Comparison between the dissolution profiles of nine meloxicam tablet brands commercially available in Buenos Aires, Argentina

In this work, the dissolution profiles of nine meloxicam tablet brands marketed in Argentina have been evaluated. As meloxicam is a Class 2 Biopharmaceutical Classification System (BSC) drug, interchangeability between commercial products must be demonstrated through in vivo bioequivalence studies. However, in our country, such studies remain to be performed. Dissolution studies have been performed according to USP 38 and evaluated by fitting experimental data to the zero and first-order, the Hixson-Crowell, the Higuchi, and the Weibull model-dependent methods. To test the pertinence of these release models, the Akaike Information Criteria (AIC) were used. All brands satisfied the dissolution profiles (phosphate buffer, pH 7.5) established in the USP. The comparison between the dissolution profiles was carried out by model-dependent and model-independent methods. The Weibull model provided the best kinetic curve adjustment. Brands I, II, IV and VI had the best fitting, with the maximum determination coefficient and the smallest AIC values. Model-independent methods included ratio test and the fit factors. The Dissolution Efficiency (DE) and Mean Dissolution Time (MDT) were analysed with ANOVA and the DGC method. In both cases, brand I did not show similarity with the rest of the brands. Using fit factors, only brands I, II and V were similar to each other. Significant differences were found among the in vitro dissolution profiles of meloxicam tablets belonging to the nine brands. As meloxicam is a class 2 BCS drug, interchangeability between commercial products must be demonstrated through in vivo bioequivalence studies. However, in Argentina, such studies remain to be performed. Our results demonstrate that caution must be exercised as regards interchangeability of generic products.