TY  - JOUR
AU  - Mitrović, Jelena
AU  - Bjelošević Žiberna, Maja
AU  - Vukadinović, Aleksandar
AU  - Knutson, Daniel E.
AU  - Sharmin, Dishary
AU  - Kremenović, Aleksandar
AU  - Ahlin Grabnar, Pegi
AU  - Planinšek, Odon
AU  - Lunter, Dominique
AU  - Cook, James M
AU  - Savić, Miroslav
AU  - Savić, Snežana
PY  - 2023
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/4982
AB  - Recently, nanocrystal dispersions have been considered as a promising formulation strategy to improve the bioavailability of the deuterated pyrazoloquinolinone ligand DK-I-56-1 (7‑methoxy-2-(4‑methoxy-d3-phenyl)-2,5-dihydro-3H-pyrazolo[4,3-c]quinolin-3-one). In the current study, the freeze-drying process (formulation and process parameters) was investigated to improve the storage stability of the previously developed formulation. Different combinations of lyoprotectant (sucrose or trehalose) and bulking agent (mannitol) were varied while formulations were freeze-dried under two conditions (primary drying at -10 or -45 °C). The obtained lyophilizates were characterized in terms of particle size, solid state properties and morphology, while the interactions within the samples were analyzed by Fourier transform infrared spectroscopy. In the preliminary study, three formulations were selected based on the high redispersibility index values (around 95%). The temperature of primary drying had no significant effect on particle size, but stability during storage was impaired for samples dried at -10 °C. Samples dried at lower temperature were more homogeneous and remained stable for three months. It was found that the optimal ratio of sucrose or trehalose to mannitol was 3:2 at a total concentration of 10% to achieve the best stability (particle size < 1.0 μm, polydispersity index < 0.250). The amorphous state of lyoprotectants probably provided a high degree of interaction with nanocrystals, while the crystalline mannitol provided an elegant cake structure. Sucrose was superior to trehalose in maintaining particle size during freeze-drying, while trehalose was more effective in keeping particle size within limits during storage. In conclusion, results demonstrated that the appropriate combination of sucrose/trehalose and mannitol together with the appropriate selection of lyophilization process parameters could yield nanocrystals with satisfactory stability.
PB  - Elsevier B.V.
T2  - European Journal of Pharmaceutical Sciences
T1  - Freeze-dried nanocrystal dispersion of novel deuterated pyrazoloquinolinone ligand (DK-I-56-1): Process parameters and lyoprotectant selection through the stability study
VL  - 189
DO  - 10.1016/j.ejps.2023.106557
ER  - 

@article{
author = "Mitrović, Jelena and Bjelošević Žiberna, Maja and Vukadinović, Aleksandar and Knutson, Daniel E. and Sharmin, Dishary and Kremenović, Aleksandar and Ahlin Grabnar, Pegi and Planinšek, Odon and Lunter, Dominique and Cook, James M and Savić, Miroslav and Savić, Snežana",
year = "2023",
abstract = "Recently, nanocrystal dispersions have been considered as a promising formulation strategy to improve the bioavailability of the deuterated pyrazoloquinolinone ligand DK-I-56-1 (7‑methoxy-2-(4‑methoxy-d3-phenyl)-2,5-dihydro-3H-pyrazolo[4,3-c]quinolin-3-one). In the current study, the freeze-drying process (formulation and process parameters) was investigated to improve the storage stability of the previously developed formulation. Different combinations of lyoprotectant (sucrose or trehalose) and bulking agent (mannitol) were varied while formulations were freeze-dried under two conditions (primary drying at -10 or -45 °C). The obtained lyophilizates were characterized in terms of particle size, solid state properties and morphology, while the interactions within the samples were analyzed by Fourier transform infrared spectroscopy. In the preliminary study, three formulations were selected based on the high redispersibility index values (around 95%). The temperature of primary drying had no significant effect on particle size, but stability during storage was impaired for samples dried at -10 °C. Samples dried at lower temperature were more homogeneous and remained stable for three months. It was found that the optimal ratio of sucrose or trehalose to mannitol was 3:2 at a total concentration of 10% to achieve the best stability (particle size < 1.0 μm, polydispersity index < 0.250). The amorphous state of lyoprotectants probably provided a high degree of interaction with nanocrystals, while the crystalline mannitol provided an elegant cake structure. Sucrose was superior to trehalose in maintaining particle size during freeze-drying, while trehalose was more effective in keeping particle size within limits during storage. In conclusion, results demonstrated that the appropriate combination of sucrose/trehalose and mannitol together with the appropriate selection of lyophilization process parameters could yield nanocrystals with satisfactory stability.",
publisher = "Elsevier B.V.",
journal = "European Journal of Pharmaceutical Sciences",
title = "Freeze-dried nanocrystal dispersion of novel deuterated pyrazoloquinolinone ligand (DK-I-56-1): Process parameters and lyoprotectant selection through the stability study",
volume = "189",
doi = "10.1016/j.ejps.2023.106557"
}

Mitrović, J., Bjelošević Žiberna, M., Vukadinović, A., Knutson, D. E., Sharmin, D., Kremenović, A., Ahlin Grabnar, P., Planinšek, O., Lunter, D., Cook, J. M., Savić, M.,& Savić, S.. (2023). Freeze-dried nanocrystal dispersion of novel deuterated pyrazoloquinolinone ligand (DK-I-56-1): Process parameters and lyoprotectant selection through the stability study. in European Journal of Pharmaceutical Sciences
Elsevier B.V.., 189.
https://doi.org/10.1016/j.ejps.2023.106557

Mitrović J, Bjelošević Žiberna M, Vukadinović A, Knutson DE, Sharmin D, Kremenović A, Ahlin Grabnar P, Planinšek O, Lunter D, Cook JM, Savić M, Savić S. Freeze-dried nanocrystal dispersion of novel deuterated pyrazoloquinolinone ligand (DK-I-56-1): Process parameters and lyoprotectant selection through the stability study. in European Journal of Pharmaceutical Sciences. 2023;189.
doi:10.1016/j.ejps.2023.106557 .

Mitrović, Jelena, Bjelošević Žiberna, Maja, Vukadinović, Aleksandar, Knutson, Daniel E., Sharmin, Dishary, Kremenović, Aleksandar, Ahlin Grabnar, Pegi, Planinšek, Odon, Lunter, Dominique, Cook, James M, Savić, Miroslav, Savić, Snežana, "Freeze-dried nanocrystal dispersion of novel deuterated pyrazoloquinolinone ligand (DK-I-56-1): Process parameters and lyoprotectant selection through the stability study" in European Journal of Pharmaceutical Sciences, 189 (2023),
https://doi.org/10.1016/j.ejps.2023.106557 . .

TY  - CONF
AU  - Mitrović, Jelena
AU  - Bjelošević, Maja
AU  - Knutson, Daniel E.
AU  - Kremenović, Aleksandar
AU  - Lunter, Dominique
AU  - Ahlin Grabnar, Pegi
AU  - Cook, James M.
AU  - Savić, Miroslav
AU  - Savić, Snežana
PY  - 2022
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/4270
AB  - 1.	INTRODUCTION 
Nanocrystal dispersions are considered as the universal formulation strategy for brick dust substances. However, the stability of these systems to aggregation represents a big issue. To overcome this, nanocrystal dispersions are usually solidified by freeze-drying (lyophilization). During this process the risk of aggregation is considered to be high, due to ice formation and/or water loss. To prevent the aggregation, For the particle size preservation, therefore, it is necessary to add cryoprotectants/lyoprotectants, among which sugars are most commonly used. To ensure good structure of the cake, bulking agents are often included in formulations, as well [1,2], although in nanocrystalline dispersions the combination of cryoprotectants and bulking agents is not frequent nor much investigated.
Nanocrystals of DK-I-56-1 (7‑methoxy‑2-(4‑methoxy‑d3-phenyl)-2,5-dihydro-3H-pyrazolo[4,3-c]quinolin-3-one), patent protected pyrazoloquinolinone ligand, have been developed recently, and characterized in terms of physicochemical properties and pharmacokinetics after intraperitoneal administration in mice. These formulations were stable for three weeks [3]. Our aim in this study was to improve the stability by freeze-drying, and investigate the influence of different concentrations and physical form of cryoprotectants (sucrose, trehalose) and bulking agent (mannitol) as well as different primary drying conditions on the aggregation prevention.

2. MATERIALS AND METHODS
2.1. Materials 
DK-I-56-1 was synthesized at the Department of Chemistry and Biochemistry, University of Wisconsin—Milwaukee, USA. The following other materials were used: polysorbate 80, poloxamer 407, sucrose, mannitol (Sigma-Aldrich Laborchemikalien GmbH, Germany) and trehalose (Carl Roth GmbH, Germany). 
2.2. Lyophilization 
Nanocrystal dispersions stabilized by polysorbate 80 and poloxamer 407 were prepared by wet ball milling [3]. After addition of mannitol (M), sucrose (S), or trehalose (T) alone or in combination samples were freeze- dried. Two processes were applied: (1) freezing at -80 °C (3 h), primary drying at -10 °C, 0.340 mbar, secondary drying at 25 °C (24 h) or (2) freezing at -50 °C (3 h), primary drying at -45 °C, 0.2 mbar (21 h), secondary drying at 20 °C (30 h). Samples were stored in crimped vials at 25 °C (lyophilization 1) or 2-8 ºC (lyophilization 2) for three months.
2.3. Physicochemical characterization
Particle size (z-ave) was measured by Zetasizer Nano ZS (Malvern Instruments, UK) and Mastersizer (Malvern Mastersizer 2000 Malvern, UK). Redispersibility index (RDI) was calculated as z-ave (before)/z-ave (after) and expressed in percentages. Physical state of samples was determined by differential scanning calorimetry (DSC1; Mettler Toledo, Switzerland),powder X-ray diffraction (Rigaku Smartlab X-ray Diffractometer) and polarized light microscopy (PLM) (Carl Zeiss ApoTome Imager Z1 microscope Zeiss, Germany). 
3. RESULTS AND DISCUSSION
Right after preparation, nanocrystal dispersions were with submicron particle size around 160 nm, and PDI below 0.2, suggesting narrow size distribution. In the cryoprotectant screening phase, sucrose and/or mannitol were added in different concentrations. It was shown that 10% of the total stabilizer concentration was needed for the particle size preservation: the achieved RDI was above 95%, while cakes with sucrose alone or in combination with mannitol in ratio 1:1 or 3:2 were also with satisfied appearance (Figure 1).  
Lyophilization was conducted above or below the glass transition temperature of the maximally freeze-concentrated solution (Tg’) (around -39 ºC). When primary drying was performed at -10 °C, no aggregation was noticed right after lyophilization, but particle size increased significantly, lowering down the RDI to < 50%, after one month storage at 25 °C. This was confirmed by laser diffraction. In lyophilization 2, with primary drying at temperature below Tg’, trehalose was also used in the same concentration as sucrose and in combination with mannitol. Interestingly, in this process parameters setup, sucrose or trehalose alone did not prevent aggregation during freeze-drying. Particle size remained almost unchanged in formulation S+M 3+2 (RDI 95%) or slightly higher in T+M 3+2 (RDI 90%), after three months storage, suggesting it was most probably the optimal combination for the stabilization. 
Physical state analysis revealed that sucrose and mannitol in samples lyophilized by process 1 were in crystalline state, as well as sucrose when used alone in lyophilization 2. Trehalose, on the other hand was amorphous in all samples containing it. Amorphous state of lyoprotectants allows maximal hydrogen bonding due to higher molecule flexibility and availability of hydroxyl groups [3]. Surprisingly, mannitol as a substance with high crystallization tendency was with low crystallinity in lyophilizates. These observations were confirmed by PLM. It is possible that it formed interactions with sucrose or nanocrystal stabilizers [4]. 
4. CONCLUSION
Results from this study demonstrated freeze- drying as an important technique for the improvement of nanocrystals stability. However, the selection of cryoprotectant and bulking agent ratio beside process parameters (primary drying at -45 ºC) was crucial to get freeze-dried samples with good stability. Sucrose or trehalose in combination with mannitol (ratio 3+2) in total concentration 10% successfully hindered aggregation, thus prolonging the stability to 3 months at 2-8 ºC.
5. REFERENCES
1.	Van Eerdenbrugh, B., et al. Top-down production of drug nanocrystals: nanosuspension stabilization, miniaturization and transformation into solid products. International journal of pharmaceutics, 2008. 364(1): 64-75.
2.	Trenkenschuh, E., and Friess, W. Freeze-drying of nanoparticles: How to overcome colloidal instability by formulation and process optimization. European Journal of Pharmaceutics and Biopharmaceutics, 2021.165: 345-360.
3.	Mitrović, J.R., et al. Overcoming the low oral bioavailability of deuterated pyrazoloquinolinone ligand DK-I-60-3 by nanonization: A knowledge-based approach. Pharmaceutics, 2021. 13(8): 1188.
4.	Kumar, S., et al. Sugars as bulking agents to prevent nano-crystal aggregation during spray or freeze-drying. International journal of pharmaceutics, 2014. 471(1-2): 303-311.
ACKNOWLEDGMENT
This research was supported by the Science Fund of the Republic of Serbia, grant No. 7749108, project Neuroimmune aspects of mood, anxiety and cognitive effects of leads/drug candidates acting at GABAA and/or sigma-2 receptors: In vitro/in vivo delineation by nano- and hiPSC-based platforms-NanoCellEmoCog.
C3  - 9th BBBB International conference on pharmaceutical sciences; 15th - 17th September, Ljubljana, Slovenia
T1  - Freeze-dried nanocrystal dispersion of novel deuterated pyrazoloquinolinone ligand (DK-I-56-1): process parameters and cryoprotectant selection through stability study
UR  - https://hdl.handle.net/21.15107/rcub_farfar_4270
ER  - 

@conference{
author = "Mitrović, Jelena and Bjelošević, Maja and Knutson, Daniel E. and Kremenović, Aleksandar and Lunter, Dominique and Ahlin Grabnar, Pegi and Cook, James M. and Savić, Miroslav and Savić, Snežana",
year = "2022",
abstract = "1.	INTRODUCTION 
Nanocrystal dispersions are considered as the universal formulation strategy for brick dust substances. However, the stability of these systems to aggregation represents a big issue. To overcome this, nanocrystal dispersions are usually solidified by freeze-drying (lyophilization). During this process the risk of aggregation is considered to be high, due to ice formation and/or water loss. To prevent the aggregation, For the particle size preservation, therefore, it is necessary to add cryoprotectants/lyoprotectants, among which sugars are most commonly used. To ensure good structure of the cake, bulking agents are often included in formulations, as well [1,2], although in nanocrystalline dispersions the combination of cryoprotectants and bulking agents is not frequent nor much investigated.
Nanocrystals of DK-I-56-1 (7‑methoxy‑2-(4‑methoxy‑d3-phenyl)-2,5-dihydro-3H-pyrazolo[4,3-c]quinolin-3-one), patent protected pyrazoloquinolinone ligand, have been developed recently, and characterized in terms of physicochemical properties and pharmacokinetics after intraperitoneal administration in mice. These formulations were stable for three weeks [3]. Our aim in this study was to improve the stability by freeze-drying, and investigate the influence of different concentrations and physical form of cryoprotectants (sucrose, trehalose) and bulking agent (mannitol) as well as different primary drying conditions on the aggregation prevention.

2. MATERIALS AND METHODS
2.1. Materials 
DK-I-56-1 was synthesized at the Department of Chemistry and Biochemistry, University of Wisconsin—Milwaukee, USA. The following other materials were used: polysorbate 80, poloxamer 407, sucrose, mannitol (Sigma-Aldrich Laborchemikalien GmbH, Germany) and trehalose (Carl Roth GmbH, Germany). 
2.2. Lyophilization 
Nanocrystal dispersions stabilized by polysorbate 80 and poloxamer 407 were prepared by wet ball milling [3]. After addition of mannitol (M), sucrose (S), or trehalose (T) alone or in combination samples were freeze- dried. Two processes were applied: (1) freezing at -80 °C (3 h), primary drying at -10 °C, 0.340 mbar, secondary drying at 25 °C (24 h) or (2) freezing at -50 °C (3 h), primary drying at -45 °C, 0.2 mbar (21 h), secondary drying at 20 °C (30 h). Samples were stored in crimped vials at 25 °C (lyophilization 1) or 2-8 ºC (lyophilization 2) for three months.
2.3. Physicochemical characterization
Particle size (z-ave) was measured by Zetasizer Nano ZS (Malvern Instruments, UK) and Mastersizer (Malvern Mastersizer 2000 Malvern, UK). Redispersibility index (RDI) was calculated as z-ave (before)/z-ave (after) and expressed in percentages. Physical state of samples was determined by differential scanning calorimetry (DSC1; Mettler Toledo, Switzerland),powder X-ray diffraction (Rigaku Smartlab X-ray Diffractometer) and polarized light microscopy (PLM) (Carl Zeiss ApoTome Imager Z1 microscope Zeiss, Germany). 
3. RESULTS AND DISCUSSION
Right after preparation, nanocrystal dispersions were with submicron particle size around 160 nm, and PDI below 0.2, suggesting narrow size distribution. In the cryoprotectant screening phase, sucrose and/or mannitol were added in different concentrations. It was shown that 10% of the total stabilizer concentration was needed for the particle size preservation: the achieved RDI was above 95%, while cakes with sucrose alone or in combination with mannitol in ratio 1:1 or 3:2 were also with satisfied appearance (Figure 1).  
Lyophilization was conducted above or below the glass transition temperature of the maximally freeze-concentrated solution (Tg’) (around -39 ºC). When primary drying was performed at -10 °C, no aggregation was noticed right after lyophilization, but particle size increased significantly, lowering down the RDI to < 50%, after one month storage at 25 °C. This was confirmed by laser diffraction. In lyophilization 2, with primary drying at temperature below Tg’, trehalose was also used in the same concentration as sucrose and in combination with mannitol. Interestingly, in this process parameters setup, sucrose or trehalose alone did not prevent aggregation during freeze-drying. Particle size remained almost unchanged in formulation S+M 3+2 (RDI 95%) or slightly higher in T+M 3+2 (RDI 90%), after three months storage, suggesting it was most probably the optimal combination for the stabilization. 
Physical state analysis revealed that sucrose and mannitol in samples lyophilized by process 1 were in crystalline state, as well as sucrose when used alone in lyophilization 2. Trehalose, on the other hand was amorphous in all samples containing it. Amorphous state of lyoprotectants allows maximal hydrogen bonding due to higher molecule flexibility and availability of hydroxyl groups [3]. Surprisingly, mannitol as a substance with high crystallization tendency was with low crystallinity in lyophilizates. These observations were confirmed by PLM. It is possible that it formed interactions with sucrose or nanocrystal stabilizers [4]. 
4. CONCLUSION
Results from this study demonstrated freeze- drying as an important technique for the improvement of nanocrystals stability. However, the selection of cryoprotectant and bulking agent ratio beside process parameters (primary drying at -45 ºC) was crucial to get freeze-dried samples with good stability. Sucrose or trehalose in combination with mannitol (ratio 3+2) in total concentration 10% successfully hindered aggregation, thus prolonging the stability to 3 months at 2-8 ºC.
5. REFERENCES
1.	Van Eerdenbrugh, B., et al. Top-down production of drug nanocrystals: nanosuspension stabilization, miniaturization and transformation into solid products. International journal of pharmaceutics, 2008. 364(1): 64-75.
2.	Trenkenschuh, E., and Friess, W. Freeze-drying of nanoparticles: How to overcome colloidal instability by formulation and process optimization. European Journal of Pharmaceutics and Biopharmaceutics, 2021.165: 345-360.
3.	Mitrović, J.R., et al. Overcoming the low oral bioavailability of deuterated pyrazoloquinolinone ligand DK-I-60-3 by nanonization: A knowledge-based approach. Pharmaceutics, 2021. 13(8): 1188.
4.	Kumar, S., et al. Sugars as bulking agents to prevent nano-crystal aggregation during spray or freeze-drying. International journal of pharmaceutics, 2014. 471(1-2): 303-311.
ACKNOWLEDGMENT
This research was supported by the Science Fund of the Republic of Serbia, grant No. 7749108, project Neuroimmune aspects of mood, anxiety and cognitive effects of leads/drug candidates acting at GABAA and/or sigma-2 receptors: In vitro/in vivo delineation by nano- and hiPSC-based platforms-NanoCellEmoCog.",
journal = "9th BBBB International conference on pharmaceutical sciences; 15th - 17th September, Ljubljana, Slovenia",
title = "Freeze-dried nanocrystal dispersion of novel deuterated pyrazoloquinolinone ligand (DK-I-56-1): process parameters and cryoprotectant selection through stability study",
url = "https://hdl.handle.net/21.15107/rcub_farfar_4270"
}

Mitrović, J., Bjelošević, M., Knutson, D. E., Kremenović, A., Lunter, D., Ahlin Grabnar, P., Cook, J. M., Savić, M.,& Savić, S.. (2022). Freeze-dried nanocrystal dispersion of novel deuterated pyrazoloquinolinone ligand (DK-I-56-1): process parameters and cryoprotectant selection through stability study. in 9th BBBB International conference on pharmaceutical sciences; 15th - 17th September, Ljubljana, Slovenia.
https://hdl.handle.net/21.15107/rcub_farfar_4270

Mitrović J, Bjelošević M, Knutson DE, Kremenović A, Lunter D, Ahlin Grabnar P, Cook JM, Savić M, Savić S. Freeze-dried nanocrystal dispersion of novel deuterated pyrazoloquinolinone ligand (DK-I-56-1): process parameters and cryoprotectant selection through stability study. in 9th BBBB International conference on pharmaceutical sciences; 15th - 17th September, Ljubljana, Slovenia. 2022;.
https://hdl.handle.net/21.15107/rcub_farfar_4270 .

Mitrović, Jelena, Bjelošević, Maja, Knutson, Daniel E., Kremenović, Aleksandar, Lunter, Dominique, Ahlin Grabnar, Pegi, Cook, James M., Savić, Miroslav, Savić, Snežana, "Freeze-dried nanocrystal dispersion of novel deuterated pyrazoloquinolinone ligand (DK-I-56-1): process parameters and cryoprotectant selection through stability study" in 9th BBBB International conference on pharmaceutical sciences; 15th - 17th September, Ljubljana, Slovenia (2022),
https://hdl.handle.net/21.15107/rcub_farfar_4270 .

TY  - JOUR
AU  - Krombholz, Richard
AU  - Fressle, Stefanie
AU  - Nikolić, Ines
AU  - Pantelić, Ivana
AU  - Savić, Snežana
AU  - Crevar-Sakač, Milkica
AU  - Lunter, Dominique
PY  - 2022
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/4333
AB  - When it comes to skin penetration analysis of a topically applied formulation, the number of suitable methods is limited, and they often lack in spatial resolution. In vivo studies are pivotal, especially in the approval of a new product, but high costs and ethical difficulties are limiting factors. For that reason, good ex vivo models for testing skin penetration are crucial. In this study, caffeine was used as a hydrophilic model drug, applied as a 2% (w/w) hydrogel, to compare different techniques for skin penetration analysis. Confocal Raman microspectroscopy (CRM) and tape stripping with subsequent HPLC analysis were used to quantify caffeine. Experiments were performed ex vivo and in vivo. Furthermore, the effect of 5% (w/w) 1,2-pentanediol on caffeine skin penetration was tested, to compare those methods regarding their effectiveness in detecting differences between both formulations.
PB  - John Wiley and Sons Inc
T2  - Experimental Dermatology
T1  - ex vivo–in vivo comparison of drug penetration analysis by confocal Raman microspectroscopy and tape stripping
VL  - 31
IS  - 12
DO  - 10.1111/exd.14672
ER  - 

@article{
author = "Krombholz, Richard and Fressle, Stefanie and Nikolić, Ines and Pantelić, Ivana and Savić, Snežana and Crevar-Sakač, Milkica and Lunter, Dominique",
year = "2022",
abstract = "When it comes to skin penetration analysis of a topically applied formulation, the number of suitable methods is limited, and they often lack in spatial resolution. In vivo studies are pivotal, especially in the approval of a new product, but high costs and ethical difficulties are limiting factors. For that reason, good ex vivo models for testing skin penetration are crucial. In this study, caffeine was used as a hydrophilic model drug, applied as a 2% (w/w) hydrogel, to compare different techniques for skin penetration analysis. Confocal Raman microspectroscopy (CRM) and tape stripping with subsequent HPLC analysis were used to quantify caffeine. Experiments were performed ex vivo and in vivo. Furthermore, the effect of 5% (w/w) 1,2-pentanediol on caffeine skin penetration was tested, to compare those methods regarding their effectiveness in detecting differences between both formulations.",
publisher = "John Wiley and Sons Inc",
journal = "Experimental Dermatology",
title = "ex vivo–in vivo comparison of drug penetration analysis by confocal Raman microspectroscopy and tape stripping",
volume = "31",
number = "12",
doi = "10.1111/exd.14672"
}

Krombholz, R., Fressle, S., Nikolić, I., Pantelić, I., Savić, S., Crevar-Sakač, M.,& Lunter, D.. (2022). ex vivo–in vivo comparison of drug penetration analysis by confocal Raman microspectroscopy and tape stripping. in Experimental Dermatology
John Wiley and Sons Inc., 31(12).
https://doi.org/10.1111/exd.14672

Krombholz R, Fressle S, Nikolić I, Pantelić I, Savić S, Crevar-Sakač M, Lunter D. ex vivo–in vivo comparison of drug penetration analysis by confocal Raman microspectroscopy and tape stripping. in Experimental Dermatology. 2022;31(12).
doi:10.1111/exd.14672 .

Krombholz, Richard, Fressle, Stefanie, Nikolić, Ines, Pantelić, Ivana, Savić, Snežana, Crevar-Sakač, Milkica, Lunter, Dominique, "ex vivo–in vivo comparison of drug penetration analysis by confocal Raman microspectroscopy and tape stripping" in Experimental Dermatology, 31, no. 12 (2022),
https://doi.org/10.1111/exd.14672 . .

TY  - JOUR
AU  - Lukić, Milica
AU  - Filipović, Mila
AU  - Pajić, Nevena
AU  - Lunter, Dominique
AU  - Božić, Dragana
AU  - Savić, Snežana
PY  - 2021
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/3912
AB  - Objective: The acidic skin pH is one of the regulating factors of skin barrier homeostasis. Topical products as extrinsic factors which influence skin pH could be used for acidification of the skin and consequent beneficial effect. To formulate stabile and safe topical emulsion product with low pH is on-going challenge and areas interesting to explore are related to the effect of acidic products on the skin pH together with development of protocols for these studies. Aim of our work was to investigate formulations of acidic topical products with glycolic acid (GA) stabilized with long chain alkyl polyglucoside emulsifier, in regard to the specific colloidal structure of the vehicle, together with effect of products with different concentration of acidic active on skin pH. Methods: Investigated formulations were basic vehicle and two creams with glycolic acid (concentration 2 and 10 wt%). Microstructure was investigated by polarization microscopy, Raman spectral imaging, thermal analysis and rheological measurements. Effects on the skin were assessed by measurement of biophysical skin parameters in vivo studies (5-hour, 24-hour and 7-days). In vitro screening of antimicrobial activity was performed against bacteria Staphylococcus epidermidis. Results: Polarization micrographs and Raman images have shown that GA does not disturb the specific colloidal structure. Together with rheological and thermal analysis obtained results have shown that GA in higher concentrations contributes to vehicles’ lamellar structure. In 5-hour study the mean values of skin pH ranged from 3.98-4.25 and 3.89-4.10 after application of products with smaller and higher GA concentration. GA samples lowered skin surface pH to 5 and less in 24-hour and 7-day study, with stronger effect of sample with more GA. Sample with 10% of GA had significant inhibitory effect on growth of S. epidermidis in 1:1 concentration. Conclusions: Investigated APG emulsifier could be used as a stabilizer for acidic topical products with GA which are characterized by satisfactory safety profile. Topical products induce acidification of the skin after short- and long-term application without barrier impairment or sign of irritation. Acidification of the skin depends on presence of ingredients which are proton donors and their concentrations.
PB  - Blackwell Publishing Ltd
T2  - International Journal of Cosmetic Science
T1  - Formulation of topical acidic products and acidification of the skin – Contribution of glycolic acid
DO  - 10.1111/ics.12707
ER  - 

@article{
author = "Lukić, Milica and Filipović, Mila and Pajić, Nevena and Lunter, Dominique and Božić, Dragana and Savić, Snežana",
year = "2021",
abstract = "Objective: The acidic skin pH is one of the regulating factors of skin barrier homeostasis. Topical products as extrinsic factors which influence skin pH could be used for acidification of the skin and consequent beneficial effect. To formulate stabile and safe topical emulsion product with low pH is on-going challenge and areas interesting to explore are related to the effect of acidic products on the skin pH together with development of protocols for these studies. Aim of our work was to investigate formulations of acidic topical products with glycolic acid (GA) stabilized with long chain alkyl polyglucoside emulsifier, in regard to the specific colloidal structure of the vehicle, together with effect of products with different concentration of acidic active on skin pH. Methods: Investigated formulations were basic vehicle and two creams with glycolic acid (concentration 2 and 10 wt%). Microstructure was investigated by polarization microscopy, Raman spectral imaging, thermal analysis and rheological measurements. Effects on the skin were assessed by measurement of biophysical skin parameters in vivo studies (5-hour, 24-hour and 7-days). In vitro screening of antimicrobial activity was performed against bacteria Staphylococcus epidermidis. Results: Polarization micrographs and Raman images have shown that GA does not disturb the specific colloidal structure. Together with rheological and thermal analysis obtained results have shown that GA in higher concentrations contributes to vehicles’ lamellar structure. In 5-hour study the mean values of skin pH ranged from 3.98-4.25 and 3.89-4.10 after application of products with smaller and higher GA concentration. GA samples lowered skin surface pH to 5 and less in 24-hour and 7-day study, with stronger effect of sample with more GA. Sample with 10% of GA had significant inhibitory effect on growth of S. epidermidis in 1:1 concentration. Conclusions: Investigated APG emulsifier could be used as a stabilizer for acidic topical products with GA which are characterized by satisfactory safety profile. Topical products induce acidification of the skin after short- and long-term application without barrier impairment or sign of irritation. Acidification of the skin depends on presence of ingredients which are proton donors and their concentrations.",
publisher = "Blackwell Publishing Ltd",
journal = "International Journal of Cosmetic Science",
title = "Formulation of topical acidic products and acidification of the skin – Contribution of glycolic acid",
doi = "10.1111/ics.12707"
}

Lukić, M., Filipović, M., Pajić, N., Lunter, D., Božić, D.,& Savić, S.. (2021). Formulation of topical acidic products and acidification of the skin – Contribution of glycolic acid. in International Journal of Cosmetic Science
Blackwell Publishing Ltd..
https://doi.org/10.1111/ics.12707

Lukić M, Filipović M, Pajić N, Lunter D, Božić D, Savić S. Formulation of topical acidic products and acidification of the skin – Contribution of glycolic acid. in International Journal of Cosmetic Science. 2021;.
doi:10.1111/ics.12707 .

Lukić, Milica, Filipović, Mila, Pajić, Nevena, Lunter, Dominique, Božić, Dragana, Savić, Snežana, "Formulation of topical acidic products and acidification of the skin – Contribution of glycolic acid" in International Journal of Cosmetic Science (2021),
https://doi.org/10.1111/ics.12707 . .

TY  - JOUR
AU  - Ilić, Tanja
AU  - Savić, Sanela
AU  - Batinić, Bojan
AU  - Marković, Bojan
AU  - Schmidberger, Markus
AU  - Lunter, Dominique
AU  - Savić, Miroslav
AU  - Savić, Snežana
PY  - 2018
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/3047
AB  - This study aimed to investigate the potential of lecithin-based nanoemulsions costabilized by sucrose esters, with and without skin pretreatment with stainless steel microneedles, to improve delivery of aceclofenac, as a model drug, into/across the skin. The characterization revealed favorable droplet size (about 180 nm), narrow size distribution (  lt  0.15), high surface charge (about - 40 mV) and satisfying long-term stability (one year at 4 +/- 1 degrees C) of the formulation costabilized by sucrose palmitate, demonstrating a similar trend observed for the reference stabilized by widely used lecithin/polysorbate 80 combination. In vitro release/permeation testing and differential stripping on the porcine ear proved the superiority of the sucrose ester- over polysorbate-based nanoemulsion. However, in vitro findings were not fully indicative of the in vivo performances - no significant differences were observed between investigated formulations in pharmacokinetic profile and total amount of aceclofenac deposited in the rat skin 24 h after dosing, simultaneously pointing to delayed aceclofenac delivery into the systemic circulation. In addition, the ratio of plasma concentrations of aceclofenac and its major metabolite in rats, diclofenac, was remarkably changed after topical application of tested nanoemulsions compared to intravenous administration of aceclofenac solution. Finally, skin pretreatment with microneedles improved aceclofenac delivery into/across the rat skin from tested formulations, resulting in 1.4-2.1-fold increased bioavailability and 1.2-1.7-fold enhanced level of aceclofenac retained in the skin, as measured 24 h after administration. Moreover, the plasma concentrations of aceclofenac 24 h after application of tested formulations (lecithin/sucrose palmitate vs. lecithin/polysorbate 80) combined with microneedles (173.37 +/- 40.50 ng/ml vs. 259.23 +/- 73.18 ng/ml) were significantly higher than those obtained through intact skin (105.69 +/- 19.53 ng/ml vs. 88.38 +/- 14.46 ng/ml). However, obtained results suggest that combination of microneedles and sucrose palmitate-costabilized nanoemulsion could be useful to attain higher skin concentration, while combination of microneedles with polysorbate 80-costabilized nanoemulsion could be a preferable option for enhancing drug delivery into the bloodstream.
PB  - Elsevier Science BV, Amsterdam
T2  - European Journal of Pharmaceutical Sciences
T1  - Combined use of biocompatible nanoemulsions and solid microneedles to improve transport of a model NSAID across the skin: In vitro and in vivo studies
VL  - 125
SP  - 110
EP  - 119
DO  - 10.1016/j.ejps.2018.09.023
ER  - 

@article{
author = "Ilić, Tanja and Savić, Sanela and Batinić, Bojan and Marković, Bojan and Schmidberger, Markus and Lunter, Dominique and Savić, Miroslav and Savić, Snežana",
year = "2018",
abstract = "This study aimed to investigate the potential of lecithin-based nanoemulsions costabilized by sucrose esters, with and without skin pretreatment with stainless steel microneedles, to improve delivery of aceclofenac, as a model drug, into/across the skin. The characterization revealed favorable droplet size (about 180 nm), narrow size distribution (  lt  0.15), high surface charge (about - 40 mV) and satisfying long-term stability (one year at 4 +/- 1 degrees C) of the formulation costabilized by sucrose palmitate, demonstrating a similar trend observed for the reference stabilized by widely used lecithin/polysorbate 80 combination. In vitro release/permeation testing and differential stripping on the porcine ear proved the superiority of the sucrose ester- over polysorbate-based nanoemulsion. However, in vitro findings were not fully indicative of the in vivo performances - no significant differences were observed between investigated formulations in pharmacokinetic profile and total amount of aceclofenac deposited in the rat skin 24 h after dosing, simultaneously pointing to delayed aceclofenac delivery into the systemic circulation. In addition, the ratio of plasma concentrations of aceclofenac and its major metabolite in rats, diclofenac, was remarkably changed after topical application of tested nanoemulsions compared to intravenous administration of aceclofenac solution. Finally, skin pretreatment with microneedles improved aceclofenac delivery into/across the rat skin from tested formulations, resulting in 1.4-2.1-fold increased bioavailability and 1.2-1.7-fold enhanced level of aceclofenac retained in the skin, as measured 24 h after administration. Moreover, the plasma concentrations of aceclofenac 24 h after application of tested formulations (lecithin/sucrose palmitate vs. lecithin/polysorbate 80) combined with microneedles (173.37 +/- 40.50 ng/ml vs. 259.23 +/- 73.18 ng/ml) were significantly higher than those obtained through intact skin (105.69 +/- 19.53 ng/ml vs. 88.38 +/- 14.46 ng/ml). However, obtained results suggest that combination of microneedles and sucrose palmitate-costabilized nanoemulsion could be useful to attain higher skin concentration, while combination of microneedles with polysorbate 80-costabilized nanoemulsion could be a preferable option for enhancing drug delivery into the bloodstream.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "European Journal of Pharmaceutical Sciences",
title = "Combined use of biocompatible nanoemulsions and solid microneedles to improve transport of a model NSAID across the skin: In vitro and in vivo studies",
volume = "125",
pages = "110-119",
doi = "10.1016/j.ejps.2018.09.023"
}

Ilić, T., Savić, S., Batinić, B., Marković, B., Schmidberger, M., Lunter, D., Savić, M.,& Savić, S.. (2018). Combined use of biocompatible nanoemulsions and solid microneedles to improve transport of a model NSAID across the skin: In vitro and in vivo studies. in European Journal of Pharmaceutical Sciences
Elsevier Science BV, Amsterdam., 125, 110-119.
https://doi.org/10.1016/j.ejps.2018.09.023

Ilić T, Savić S, Batinić B, Marković B, Schmidberger M, Lunter D, Savić M, Savić S. Combined use of biocompatible nanoemulsions and solid microneedles to improve transport of a model NSAID across the skin: In vitro and in vivo studies. in European Journal of Pharmaceutical Sciences. 2018;125:110-119.
doi:10.1016/j.ejps.2018.09.023 .

Ilić, Tanja, Savić, Sanela, Batinić, Bojan, Marković, Bojan, Schmidberger, Markus, Lunter, Dominique, Savić, Miroslav, Savić, Snežana, "Combined use of biocompatible nanoemulsions and solid microneedles to improve transport of a model NSAID across the skin: In vitro and in vivo studies" in European Journal of Pharmaceutical Sciences, 125 (2018):110-119,
https://doi.org/10.1016/j.ejps.2018.09.023 . .

TY  - JOUR
AU  - Nikolić, Ines
AU  - Lunter, Dominique
AU  - Ranđelović, Danijela
AU  - Žugić, Ana R.
AU  - Tadić, Vanja M.
AU  - Marković, Bojan
AU  - Cekić, Nebojša
AU  - Živković, Lada
AU  - Topalović, Dijana
AU  - Potparević, Biljana
AU  - Daniels, Rolf
AU  - Savić, Snežana
PY  - 2018
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/3084
AB  - The objective of this work was to investigate and profoundly characterize low-energy nanoemulsions as multifunctional carriers, with slight reference to dermal administration. An evidence-based approach was offered for deepening the knowledge on their formation via spontaneous emulsification. Curcumin, a compound of natural origin, potentially powerful therapeutic, was chosen as a model API. Due to curcumin's demanding properties (instability, poor solubility, low permeability), its potentials remain unreached. Low-energy nanoemulsions were considered carriers capable of overcoming imposed obstacles. Formulation consisting of Polysorbate 80 and soybean lecithin as stabilizers (9:1, 10%), medium-chain triglycerides as the oil phase (10%) and ultrapure water was selected for curcumin incorporation in 3 different concentrations (1, 2 and 3 mg/mL). Physicochemical stability was demonstrated during 3 months of monitoring (mean droplet size: 111.3-146.8 nm; PDI  lt  0.2; pH: 4.73-5.73). Curcumin's release from developed vehicles followed Higuchi's kinetics. DPPH (IC50 = 0.1187 mg/ mL) and FRAP (1.19 +/- 0.02 mmol/g) assays confirmed that curcumin acts as a potent antioxidant through different mechanisms, with no alterations after incorporation in the formulation. High biocompatibility in line with antigenotoxic activity of curcumin-loaded formulations (protective and reparative) was estimated through Comet assay. A multidisciplinary approach is needed to fully characterize developed systems, directing them to more concrete application possibilities.
PB  - Elsevier Science BV, Amsterdam
T2  - International Journal of Pharmaceutics
T1  - Curcumin-loaded low-energy nanoemulsions as a prototype of multifunctional vehicles for different administration routes: Physicochemical and in vitro peculiarities important for dermal application
VL  - 550
IS  - 1-2
SP  - 333
EP  - 346
DO  - 10.1016/j.ijpharm.2018.08.060
ER  - 

@article{
author = "Nikolić, Ines and Lunter, Dominique and Ranđelović, Danijela and Žugić, Ana R. and Tadić, Vanja M. and Marković, Bojan and Cekić, Nebojša and Živković, Lada and Topalović, Dijana and Potparević, Biljana and Daniels, Rolf and Savić, Snežana",
year = "2018",
abstract = "The objective of this work was to investigate and profoundly characterize low-energy nanoemulsions as multifunctional carriers, with slight reference to dermal administration. An evidence-based approach was offered for deepening the knowledge on their formation via spontaneous emulsification. Curcumin, a compound of natural origin, potentially powerful therapeutic, was chosen as a model API. Due to curcumin's demanding properties (instability, poor solubility, low permeability), its potentials remain unreached. Low-energy nanoemulsions were considered carriers capable of overcoming imposed obstacles. Formulation consisting of Polysorbate 80 and soybean lecithin as stabilizers (9:1, 10%), medium-chain triglycerides as the oil phase (10%) and ultrapure water was selected for curcumin incorporation in 3 different concentrations (1, 2 and 3 mg/mL). Physicochemical stability was demonstrated during 3 months of monitoring (mean droplet size: 111.3-146.8 nm; PDI  lt  0.2; pH: 4.73-5.73). Curcumin's release from developed vehicles followed Higuchi's kinetics. DPPH (IC50 = 0.1187 mg/ mL) and FRAP (1.19 +/- 0.02 mmol/g) assays confirmed that curcumin acts as a potent antioxidant through different mechanisms, with no alterations after incorporation in the formulation. High biocompatibility in line with antigenotoxic activity of curcumin-loaded formulations (protective and reparative) was estimated through Comet assay. A multidisciplinary approach is needed to fully characterize developed systems, directing them to more concrete application possibilities.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "International Journal of Pharmaceutics",
title = "Curcumin-loaded low-energy nanoemulsions as a prototype of multifunctional vehicles for different administration routes: Physicochemical and in vitro peculiarities important for dermal application",
volume = "550",
number = "1-2",
pages = "333-346",
doi = "10.1016/j.ijpharm.2018.08.060"
}

Nikolić, I., Lunter, D., Ranđelović, D., Žugić, A. R., Tadić, V. M., Marković, B., Cekić, N., Živković, L., Topalović, D., Potparević, B., Daniels, R.,& Savić, S.. (2018). Curcumin-loaded low-energy nanoemulsions as a prototype of multifunctional vehicles for different administration routes: Physicochemical and in vitro peculiarities important for dermal application. in International Journal of Pharmaceutics
Elsevier Science BV, Amsterdam., 550(1-2), 333-346.
https://doi.org/10.1016/j.ijpharm.2018.08.060

Nikolić I, Lunter D, Ranđelović D, Žugić AR, Tadić VM, Marković B, Cekić N, Živković L, Topalović D, Potparević B, Daniels R, Savić S. Curcumin-loaded low-energy nanoemulsions as a prototype of multifunctional vehicles for different administration routes: Physicochemical and in vitro peculiarities important for dermal application. in International Journal of Pharmaceutics. 2018;550(1-2):333-346.
doi:10.1016/j.ijpharm.2018.08.060 .

Nikolić, Ines, Lunter, Dominique, Ranđelović, Danijela, Žugić, Ana R., Tadić, Vanja M., Marković, Bojan, Cekić, Nebojša, Živković, Lada, Topalović, Dijana, Potparević, Biljana, Daniels, Rolf, Savić, Snežana, "Curcumin-loaded low-energy nanoemulsions as a prototype of multifunctional vehicles for different administration routes: Physicochemical and in vitro peculiarities important for dermal application" in International Journal of Pharmaceutics, 550, no. 1-2 (2018):333-346,
https://doi.org/10.1016/j.ijpharm.2018.08.060 . .

TY  - JOUR
AU  - Zhang, Z.
AU  - Lukić, Milica
AU  - Savić, Snežana
AU  - Lunter, Dominique
PY  - 2018
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/3043
AB  - Objective The aim of the study was to develop formulations to deliver physiological lipids into skin in an attempt to repair defective barrier function. MethodsResultsPhysiological cholesterol and linoleic acid were incorporated into basic cream and non-ionic cream to prepare skin repair formulations. Homogeneity and storage stability of the developed creams were examined by polarized light microscopy. Ex vivo evaluation was conducted using lipid-deficient skin samples and confocal Raman microspectroscopy. A 7-day invivo study was performed on volunteers to study the repairing efficacy. Homogeneous texture was seen in the prepared skin repair formulations. The application of the creams led to substantially increased lipid levels compared to the reference in the lipid-deficient skin in exvivo study. Twice-a-day application of the skin repair creams provided a reinforcement of the skin barrier as transepidermal water loss (TEWL) was significantly decreased. ConclusionResumeThe skin repair creams showed excellent efficacy in skin recovery. They have great potentials for treating impaired skin barrier associated with depletion of lipids in stratum corneum. ObjectifMethodesl'objectif de l'etude etait de developper des formulations pour delivrer des lipides physiologiques dans la peau dans le but de reparer une fonction barriere defectueuse. du cholesterol et de l'acide linoleique physiologiques ont ete incorpores dans une creme basique et une creme non-ionique afin de realiser des formulations pour la reparation de la peau. L'homogeneite et la stabilite au cours de la conservation des cremes developpees ont ete examinees par microscopie en lumiere polarisee. Une evaluation exvivo a ete realisee en utilisant des echantillons de peau delipidee et la microspectroscopie confocale Raman. Une etude invivo de 7jours a ete realisee sur des volontaires pour etudier l'efficacite de la reparation. ResultatsConclusionune texture homogene a ete observee dans les formulations preparees pour reparation cutanee. L'application des cremes a conduit a une augmentation substantielle des taux de lipides par rapport au temoin dans l'etude exvivo sur la peau delipidee. Une application deux fois par jour des cremes reparatrices cutanees a permis de renforcer la barriere cutanee, car la perte d'eau transepidermique (transepidermal water loss, TEWL) a ete significativement diminuee. les cremes reparatrices cutanees ont montre une excellente efficacite au niveau de la regeneration de la peau. Elles possedent des potentiels eleves pour traiter une alteration de la barriere cutanee associee a un appauvrissement en lipides de la couche cornee.
PB  - Wiley, Hoboken
T2  - International Journal of Cosmetic Science
T1  - Reinforcement of barrier function - skin repair formulations to deliver physiological lipids into skin
VL  - 40
IS  - 5
SP  - 494
EP  - 501
DO  - 10.1111/ics.12491
ER  - 

@article{
author = "Zhang, Z. and Lukić, Milica and Savić, Snežana and Lunter, Dominique",
year = "2018",
abstract = "Objective The aim of the study was to develop formulations to deliver physiological lipids into skin in an attempt to repair defective barrier function. MethodsResultsPhysiological cholesterol and linoleic acid were incorporated into basic cream and non-ionic cream to prepare skin repair formulations. Homogeneity and storage stability of the developed creams were examined by polarized light microscopy. Ex vivo evaluation was conducted using lipid-deficient skin samples and confocal Raman microspectroscopy. A 7-day invivo study was performed on volunteers to study the repairing efficacy. Homogeneous texture was seen in the prepared skin repair formulations. The application of the creams led to substantially increased lipid levels compared to the reference in the lipid-deficient skin in exvivo study. Twice-a-day application of the skin repair creams provided a reinforcement of the skin barrier as transepidermal water loss (TEWL) was significantly decreased. ConclusionResumeThe skin repair creams showed excellent efficacy in skin recovery. They have great potentials for treating impaired skin barrier associated with depletion of lipids in stratum corneum. ObjectifMethodesl'objectif de l'etude etait de developper des formulations pour delivrer des lipides physiologiques dans la peau dans le but de reparer une fonction barriere defectueuse. du cholesterol et de l'acide linoleique physiologiques ont ete incorpores dans une creme basique et une creme non-ionique afin de realiser des formulations pour la reparation de la peau. L'homogeneite et la stabilite au cours de la conservation des cremes developpees ont ete examinees par microscopie en lumiere polarisee. Une evaluation exvivo a ete realisee en utilisant des echantillons de peau delipidee et la microspectroscopie confocale Raman. Une etude invivo de 7jours a ete realisee sur des volontaires pour etudier l'efficacite de la reparation. ResultatsConclusionune texture homogene a ete observee dans les formulations preparees pour reparation cutanee. L'application des cremes a conduit a une augmentation substantielle des taux de lipides par rapport au temoin dans l'etude exvivo sur la peau delipidee. Une application deux fois par jour des cremes reparatrices cutanees a permis de renforcer la barriere cutanee, car la perte d'eau transepidermique (transepidermal water loss, TEWL) a ete significativement diminuee. les cremes reparatrices cutanees ont montre une excellente efficacite au niveau de la regeneration de la peau. Elles possedent des potentiels eleves pour traiter une alteration de la barriere cutanee associee a un appauvrissement en lipides de la couche cornee.",
publisher = "Wiley, Hoboken",
journal = "International Journal of Cosmetic Science",
title = "Reinforcement of barrier function - skin repair formulations to deliver physiological lipids into skin",
volume = "40",
number = "5",
pages = "494-501",
doi = "10.1111/ics.12491"
}

Zhang, Z., Lukić, M., Savić, S.,& Lunter, D.. (2018). Reinforcement of barrier function - skin repair formulations to deliver physiological lipids into skin. in International Journal of Cosmetic Science
Wiley, Hoboken., 40(5), 494-501.
https://doi.org/10.1111/ics.12491

Zhang Z, Lukić M, Savić S, Lunter D. Reinforcement of barrier function - skin repair formulations to deliver physiological lipids into skin. in International Journal of Cosmetic Science. 2018;40(5):494-501.
doi:10.1111/ics.12491 .

Zhang, Z., Lukić, Milica, Savić, Snežana, Lunter, Dominique, "Reinforcement of barrier function - skin repair formulations to deliver physiological lipids into skin" in International Journal of Cosmetic Science, 40, no. 5 (2018):494-501,
https://doi.org/10.1111/ics.12491 . .

TY  - JOUR
AU  - Ilić, Tanja
AU  - Pantelić, Ivana
AU  - Lunter, Dominique
AU  - Dodević, Sanela
AU  - Marković, Bojan
AU  - Ranković, Dragana
AU  - Daniels, Rolf
AU  - Savić, Snežana
PY  - 2017
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2826
AB  - This work aimed to prove the ability of "ready-to-use" topical vehicles based on alkyl polyglucoside-mixed emulsifier (with/without co-solvent modifications) to replace the conventionally used pharmacopoeial bases (e.g., non-ionic hydrophilic cream) in compounding practice. For this purpose, considering the regulatory efforts to establish alternative, scientifically valid methods for evaluating therapeutic equivalence of topical semisolids, we performed a comparative assessment of microstructure, selected critical quality attributes (CQAs) and in vitro/in vivo product performances, by utilizing aceclofenac as a model drug. The differences in composition between investigated samples have imposed remarkable variances in monitored CQAs (particularly in the amount of aceclofenac dissolved, rheological properties and water distribution mode), reflecting the distinct differences in microstructure formed, as partially observed by polarization microscopy and confocal Raman spectral imaging. Although not fully indicative of the in vivo performances, in vitro release data (vertical diffusion vs. immersion cells) proved the microstructure peculiarities, asserting the rheological properties as decisive factor for obtained liberation profiles. Contrary, in vitro permeation results obtained using pig ear epidermis correlated well with in vivo dermatopharmacokinetic data and distinguished unequivocally between tested formulations, emphasizing the importance of skin/vehicle interactions. In summary, suggested multi-faceted approach can provide adequate proof on topical semisolids therapeutic equivalence or lack thereof.
PB  - Elsevier Science BV, Amsterdam
T2  - International Journal of Pharmaceutics
T1  - Critical quality attributes, in vitro release and correlated in vitro skin permeation-in vivo tape stripping collective data for demonstrating therapeutic (non) equivalence of topical semisolids: A case study of "ready-to-use" vehicles
VL  - 528
IS  - 1-2
SP  - 253
EP  - 267
DO  - 10.1016/j.ijpharm.2017.06.018
ER  - 

@article{
author = "Ilić, Tanja and Pantelić, Ivana and Lunter, Dominique and Dodević, Sanela and Marković, Bojan and Ranković, Dragana and Daniels, Rolf and Savić, Snežana",
year = "2017",
abstract = "This work aimed to prove the ability of "ready-to-use" topical vehicles based on alkyl polyglucoside-mixed emulsifier (with/without co-solvent modifications) to replace the conventionally used pharmacopoeial bases (e.g., non-ionic hydrophilic cream) in compounding practice. For this purpose, considering the regulatory efforts to establish alternative, scientifically valid methods for evaluating therapeutic equivalence of topical semisolids, we performed a comparative assessment of microstructure, selected critical quality attributes (CQAs) and in vitro/in vivo product performances, by utilizing aceclofenac as a model drug. The differences in composition between investigated samples have imposed remarkable variances in monitored CQAs (particularly in the amount of aceclofenac dissolved, rheological properties and water distribution mode), reflecting the distinct differences in microstructure formed, as partially observed by polarization microscopy and confocal Raman spectral imaging. Although not fully indicative of the in vivo performances, in vitro release data (vertical diffusion vs. immersion cells) proved the microstructure peculiarities, asserting the rheological properties as decisive factor for obtained liberation profiles. Contrary, in vitro permeation results obtained using pig ear epidermis correlated well with in vivo dermatopharmacokinetic data and distinguished unequivocally between tested formulations, emphasizing the importance of skin/vehicle interactions. In summary, suggested multi-faceted approach can provide adequate proof on topical semisolids therapeutic equivalence or lack thereof.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "International Journal of Pharmaceutics",
title = "Critical quality attributes, in vitro release and correlated in vitro skin permeation-in vivo tape stripping collective data for demonstrating therapeutic (non) equivalence of topical semisolids: A case study of "ready-to-use" vehicles",
volume = "528",
number = "1-2",
pages = "253-267",
doi = "10.1016/j.ijpharm.2017.06.018"
}

Ilić, T., Pantelić, I., Lunter, D., Dodević, S., Marković, B., Ranković, D., Daniels, R.,& Savić, S.. (2017). Critical quality attributes, in vitro release and correlated in vitro skin permeation-in vivo tape stripping collective data for demonstrating therapeutic (non) equivalence of topical semisolids: A case study of "ready-to-use" vehicles. in International Journal of Pharmaceutics
Elsevier Science BV, Amsterdam., 528(1-2), 253-267.
https://doi.org/10.1016/j.ijpharm.2017.06.018

Ilić T, Pantelić I, Lunter D, Dodević S, Marković B, Ranković D, Daniels R, Savić S. Critical quality attributes, in vitro release and correlated in vitro skin permeation-in vivo tape stripping collective data for demonstrating therapeutic (non) equivalence of topical semisolids: A case study of "ready-to-use" vehicles. in International Journal of Pharmaceutics. 2017;528(1-2):253-267.
doi:10.1016/j.ijpharm.2017.06.018 .

Ilić, Tanja, Pantelić, Ivana, Lunter, Dominique, Dodević, Sanela, Marković, Bojan, Ranković, Dragana, Daniels, Rolf, Savić, Snežana, "Critical quality attributes, in vitro release and correlated in vitro skin permeation-in vivo tape stripping collective data for demonstrating therapeutic (non) equivalence of topical semisolids: A case study of "ready-to-use" vehicles" in International Journal of Pharmaceutics, 528, no. 1-2 (2017):253-267,
https://doi.org/10.1016/j.ijpharm.2017.06.018 . .

TY  - JOUR
AU  - Heck, Rouven
AU  - Lukić, Milica
AU  - Savić, Snežana
AU  - Daniels, Rolf
AU  - Lunter, Dominique
PY  - 2017
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2806
AB  - Aim: The purpose of this study was to evaluate skin permeation and penetration of nonivamide which has been formulated in novel film-forming formulations (FFFs). These formulations aim to prolong the availability of capsaicinoids which are used in long-term treatment of chronic pruritus. Methods: An oily solution of nonivamide was loaded into porous silica particles which then were suspended in an aqueous dispersion of a sustained release polymer. Permeation and penetration experiments were performed ex vivo with postauricular porcine skin using modified Franz diffusion cells. The penetrated drug amount was assessed ex vivo by skin surface biopsy followed by cryo-sectioning. Furthermore, in vivo skin irritation experiments were performed to compare the potential skin irritation caused by the FFFs to conventionally used semi-solid formulations. Results: Permeation rates of nonivamide from FFF through the skin are comparable to that from clinically used immediate release formulations. This elucidates the therapeutic safety profile of the novel FFF. Penetration studies confirmed the prolonged drug availability at the site of action. FFFs were found not to irritate the skin of healthy volunteers. Conclusion: FFFs with sustained nonivamide penetration represent safe and easy-to-use formulations. They therefore may improve the treatment of chronic pruritus with capsaicinoids by enhancing patient compliance through a sustained release regime.
PB  - Elsevier Science BV, Amsterdam
T2  - European Journal of Pharmaceutical Sciences
T1  - Ex vivo skin permeation and penetration of nonivamide from and in vivo skin tolerability of film-forming formulations containing porous silica
VL  - 106
SP  - 34
EP  - 40
DO  - 10.1016/j.ejps.2017.05.045
ER  - 

@article{
author = "Heck, Rouven and Lukić, Milica and Savić, Snežana and Daniels, Rolf and Lunter, Dominique",
year = "2017",
abstract = "Aim: The purpose of this study was to evaluate skin permeation and penetration of nonivamide which has been formulated in novel film-forming formulations (FFFs). These formulations aim to prolong the availability of capsaicinoids which are used in long-term treatment of chronic pruritus. Methods: An oily solution of nonivamide was loaded into porous silica particles which then were suspended in an aqueous dispersion of a sustained release polymer. Permeation and penetration experiments were performed ex vivo with postauricular porcine skin using modified Franz diffusion cells. The penetrated drug amount was assessed ex vivo by skin surface biopsy followed by cryo-sectioning. Furthermore, in vivo skin irritation experiments were performed to compare the potential skin irritation caused by the FFFs to conventionally used semi-solid formulations. Results: Permeation rates of nonivamide from FFF through the skin are comparable to that from clinically used immediate release formulations. This elucidates the therapeutic safety profile of the novel FFF. Penetration studies confirmed the prolonged drug availability at the site of action. FFFs were found not to irritate the skin of healthy volunteers. Conclusion: FFFs with sustained nonivamide penetration represent safe and easy-to-use formulations. They therefore may improve the treatment of chronic pruritus with capsaicinoids by enhancing patient compliance through a sustained release regime.",
publisher = "Elsevier Science BV, Amsterdam",
journal = "European Journal of Pharmaceutical Sciences",
title = "Ex vivo skin permeation and penetration of nonivamide from and in vivo skin tolerability of film-forming formulations containing porous silica",
volume = "106",
pages = "34-40",
doi = "10.1016/j.ejps.2017.05.045"
}

Heck, R., Lukić, M., Savić, S., Daniels, R.,& Lunter, D.. (2017). Ex vivo skin permeation and penetration of nonivamide from and in vivo skin tolerability of film-forming formulations containing porous silica. in European Journal of Pharmaceutical Sciences
Elsevier Science BV, Amsterdam., 106, 34-40.
https://doi.org/10.1016/j.ejps.2017.05.045

Heck R, Lukić M, Savić S, Daniels R, Lunter D. Ex vivo skin permeation and penetration of nonivamide from and in vivo skin tolerability of film-forming formulations containing porous silica. in European Journal of Pharmaceutical Sciences. 2017;106:34-40.
doi:10.1016/j.ejps.2017.05.045 .

Heck, Rouven, Lukić, Milica, Savić, Snežana, Daniels, Rolf, Lunter, Dominique, "Ex vivo skin permeation and penetration of nonivamide from and in vivo skin tolerability of film-forming formulations containing porous silica" in European Journal of Pharmaceutical Sciences, 106 (2017):34-40,
https://doi.org/10.1016/j.ejps.2017.05.045 . .

TY  - JOUR
AU  - Žugić, Ana R.
AU  - Lunter, Dominique
AU  - Daniels, Rolf
AU  - Pantelić, Ivana
AU  - Tasić-Kostov, Marija
AU  - Tadić, Vanja M.
AU  - Mišić, Dušan
AU  - Arsić, Ivana A.
AU  - Savić, Snežana
PY  - 2016
UR  - https://farfar.pharmacy.bg.ac.rs/handle/123456789/2588
AB  - Topical treatment of skin infections is often limited by drawbacks related to both antimicrobial agents and their vehicles. In addition, considering the growing promotion of natural therapeutic products, our objective was to develop and evaluate naturally-based emulsion system, as prospective topical formulation for skin infections-treatment. Therefore, alkyl polyglucoside surfactants were used for stabilization of a vehicle serving as potential carrier for supercritical CO2-extract of Usnea barbata, lichen with well-documented antimicrobial activity, incorporated using two protocols and three concentrations. Comprehensive physicochemical characterization suggested possible involvement of extract's particles in stabilization of the investigated system. Raman spectral imaging served as the key method in disclosing extract's particles potential to participate in the microstructure of the tested emulsion system via three mechanisms: (1) particle-particle aggregation, (2) adsorption at the oil-water interface and (3) hydrophobic particle-surfactant interactions. Stated extract-vehicle interaction proved to be correlated to the preparation procedure and extract concentration on one hand and to affect the physicochemical and biopharmaceutical features of investigated system, on the other hand. Thereafter, formulation with the best preliminary stability and liberation profile was selected for further efficiency and in vivo skin irritation potential evaluation, implying pertinent in vitro antimicrobial activity against G+ bacteria and overall satisfying preliminary safety profile.
PB  - Taylor & Francis Ltd, Abingdon
T2  - Pharmaceutical Development and Technology
T1  - Usnea barbata CO2-supercritical extract in alkyl polyglucoside-based emulsion system: contribution of Confocal Raman imaging to the formulation development of a natural product
VL  - 21
IS  - 5
SP  - 563
EP  - 575
DO  - 10.3109/10837450.2015.1026606
ER  - 

@article{
author = "Žugić, Ana R. and Lunter, Dominique and Daniels, Rolf and Pantelić, Ivana and Tasić-Kostov, Marija and Tadić, Vanja M. and Mišić, Dušan and Arsić, Ivana A. and Savić, Snežana",
year = "2016",
abstract = "Topical treatment of skin infections is often limited by drawbacks related to both antimicrobial agents and their vehicles. In addition, considering the growing promotion of natural therapeutic products, our objective was to develop and evaluate naturally-based emulsion system, as prospective topical formulation for skin infections-treatment. Therefore, alkyl polyglucoside surfactants were used for stabilization of a vehicle serving as potential carrier for supercritical CO2-extract of Usnea barbata, lichen with well-documented antimicrobial activity, incorporated using two protocols and three concentrations. Comprehensive physicochemical characterization suggested possible involvement of extract's particles in stabilization of the investigated system. Raman spectral imaging served as the key method in disclosing extract's particles potential to participate in the microstructure of the tested emulsion system via three mechanisms: (1) particle-particle aggregation, (2) adsorption at the oil-water interface and (3) hydrophobic particle-surfactant interactions. Stated extract-vehicle interaction proved to be correlated to the preparation procedure and extract concentration on one hand and to affect the physicochemical and biopharmaceutical features of investigated system, on the other hand. Thereafter, formulation with the best preliminary stability and liberation profile was selected for further efficiency and in vivo skin irritation potential evaluation, implying pertinent in vitro antimicrobial activity against G+ bacteria and overall satisfying preliminary safety profile.",
publisher = "Taylor & Francis Ltd, Abingdon",
journal = "Pharmaceutical Development and Technology",
title = "Usnea barbata CO2-supercritical extract in alkyl polyglucoside-based emulsion system: contribution of Confocal Raman imaging to the formulation development of a natural product",
volume = "21",
number = "5",
pages = "563-575",
doi = "10.3109/10837450.2015.1026606"
}

Žugić, A. R., Lunter, D., Daniels, R., Pantelić, I., Tasić-Kostov, M., Tadić, V. M., Mišić, D., Arsić, I. A.,& Savić, S.. (2016). Usnea barbata CO2-supercritical extract in alkyl polyglucoside-based emulsion system: contribution of Confocal Raman imaging to the formulation development of a natural product. in Pharmaceutical Development and Technology
Taylor & Francis Ltd, Abingdon., 21(5), 563-575.
https://doi.org/10.3109/10837450.2015.1026606

Žugić AR, Lunter D, Daniels R, Pantelić I, Tasić-Kostov M, Tadić VM, Mišić D, Arsić IA, Savić S. Usnea barbata CO2-supercritical extract in alkyl polyglucoside-based emulsion system: contribution of Confocal Raman imaging to the formulation development of a natural product. in Pharmaceutical Development and Technology. 2016;21(5):563-575.
doi:10.3109/10837450.2015.1026606 .

Žugić, Ana R., Lunter, Dominique, Daniels, Rolf, Pantelić, Ivana, Tasić-Kostov, Marija, Tadić, Vanja M., Mišić, Dušan, Arsić, Ivana A., Savić, Snežana, "Usnea barbata CO2-supercritical extract in alkyl polyglucoside-based emulsion system: contribution of Confocal Raman imaging to the formulation development of a natural product" in Pharmaceutical Development and Technology, 21, no. 5 (2016):563-575,
https://doi.org/10.3109/10837450.2015.1026606 . .