Formulation and bioequivalence of two Valsartan/Amlodipine immediate release tablets after a single oral administration.

The aim of this study was to formulate a film-coated Valsartan/Amlodipine (VS/AM) immediate release tablets and to evaluate their in vivo release profile. VS/AM core tablets were manufactured using dry granulation method. Opadry aqueous coating dispersion was used as film coating material. Dissolution of the film coated tablets was tested in 900 ml of 0.5% SLS media, bioequivalence of tablets was tested by comparisons against the reference brand product. The ICH guidelines were used to evaluate the stability of the obtained tablets. The coated tablets were subjected to gastric pH, and drug release was analyzed using HPLC system to evaluate the efficiency of the film coat. The coated tablets had no defects. VS/AM release met the FDA guidelines for bioequivalence studies. Statistical comparison of the main pharmacokinetic parameters showed no significant difference between test and reference. These findings suggest that aqueous film coating with Opadry system is an easy and economical approach for preparing stable film coated VS/AM tablets without compromising their in vivo drugs release.

Formulation and bioequivalence of two valsartan tablets after a single oral administration.

The aim of this study is to assess the quality of Valzan(®) tablet (160 mg, valsartan immediate release test formulation) by comparing its pharmacokinetic parameters with Diovan(®) tablet (160 mg, valsartan reference formulation). Valzan(®) tablets were prepared according to a dry granulation method (roll compaction). To assess the bioequivalence of Valzan(®) tablets a randomized, two-way, crossover, bioequivalence study was performed in 24 healthy male volunteers. The selected volunteers were divided into two groups of 12 subjects. One group was treated with the reference formulation (Diovan(®)) and the other one with the generic Valzan(®), with a cross-over after the drug washout period of 14 days. Blood samples were collected at fixed time intervals and valsartan concentrations were determined by a validated HPLC assay method. The pharmacokinetic parameters AUC(0-48), AUC(0-∞), C(max), T(max), K(e) and T(1/2) were determined for both the tablets and were compared statistically to evaluate the bioequivalence between the two brands of valsartan, using the statistical model recommended by the FDA. The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals (CI) fell within the acceptable range for bioequivalence. Based on this statistical evaluation it was concluded that the test tablets (Valzan(®)) is well formulated, since it exhibits pharmacokinetic profile comparable to the reference brand Diovan(®).