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 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 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 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.

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Aims: An easy, sensitive and inexpensive volumetric method for the determination of rosuvastatin calcium in raw material has been developed. Methodology: The titrimetric method is based on the reaction of calcium with a solution of Disodium ethylene diaminotetraacetate (EDTA) -Magnesium 0.01 M. Hydroxynaphtol blue was used as indicator. It changes from pink to blue at pH = 10 at the end point of the titration. The method was validated for linearity, precision and accuracy, following the suggestions of the International Conference on Harmonization (ICH). Results: The linearity of the volumetric method was determined by analysis of six replicates at 80%, Short Communication100% and 120% and three replicates at 90% and 110% of analyte concentration. The calibration curve was linear, with r = 0.9998. Assay method precision was evaluated by carrying out six independent assays of bulk drug and the intermediate precision was also verified using different analyst and different day in the same laboratory. Accuracy (mean recovery 99.0%) and precision were found to be satisfactory. Conclusion:The proposed method can be used for quality control assay of rosuvastatin calcium in bulk drug.