Effects of co-processing variables on properties of metronidazole tablets containing co-processed starch as sole excipient
Formulation development of pharmaceutical products is often subjected to trials and errors, and to find the best formulary could be time consuming and financially wasteful. Factorial experimental design has been proposed to optimized formulation of pharmaceutical products. In this study a 23 factorial experimental design has been used to quantitatively study individual and interaction effects of the type of gum (A), concentration of the gum (B) and the compressing pressure (C) on the tablet friability (FR), tensile strength (TS) and disintegration time (DT), on metronidazole tablet formulations. Metronidazole tablets (Metro) containing the co -processed starches as sole excipients were prepared by direct compression method and were evaluated for the tablet friability (FR), tensile strength (TS) and disintegration time (DT). The results were analyzed using drug design expert software and ANOVA. The individual and combined effects of A, B and C on DT, TS and FR were highly significant (P<0.05). In general, the ranking of the individual and sum of effects, on FR was B ≥A ≥ C ≥ BC ≥ AC ≥ABC, while that of DT and Ts were A ≥ B ≥ C ≥ AC ≥ BC = ABC and A ≥B ≥C ≥ AB = BC ≥ ABC respectively. The results generally showed that co-processing variables such as A, B and C individually and together could considerably affect tableting properties such as FR DT and TS.
Keywords: Direct compression; Factorial design; Tensile Strength; Friability; Tablet disintegration