Influence of pH and agitation intensity on drug dissolution from tablets evaluated by means of factorial design

Abstract

Dissolution rate of a drug substance can be strongly influenced by the experimental conditions employed, among which agitation intensity and pH value were recognized as the most important. A complete two-factor, three-level factorial design followed by multiple regression analysis was applied in order to investigate the influence of pH and agitation intensity on paracetamol (CAS 103-90-2) and acetylsalicylic acid (CAS 50-78-2) dissolution from conventional tablets. Mean dissolution time, amount of drug dissolved after 30 min and first-order dissolution rate constant were evaluated as response variables in terms of their applicability to characterize different release profiles. The obtained results indicated that factorially designed experiments present a valuable tool in dissolution method development. Mean dissolution time showed to be the most useful response criterion capable to differentiate between dissolution curves of different shape.