Formulation and evaluation of a buccoadhesive captopril tablets

ABSTRACT

Buccoadhesive tablets of captopril were prepared by direct compression of the drug with different polymers; Carbopol 934 [CP 934], EudragitRS 100 [EU RS 100], Chitosan [Ch], Hydroxpropyl methylcellulose [HPMC] and Polyvinylpyrrolidone K[30] [PVP K[30]] either singly or in blends of different ratios. The tablets were evaluated for their weight variation, drug content uniformity, friability, hardness, swelling index, surface pH, in-vitro bioadhesive strength and release characteristics. The bioavailability and the pharmacokinetics parameters of captopril from two selected formulations [CP 934HPMC 64 andChHPMC 64] were evaluated. The in-vitro bioadhesive strength and release characteristics were found to be a function of the type of polymer and ratio of polymer blends. Swelling and bioadhesive characteristics were determined for both plain and medicated tablets. The high concentration of carbopol and chitosan containing formulations showed the greatest adhesive strength. The mean pharmacokinetic parameters of captopril after buccoadhesive tablet administration were C[max] 506.9 ng/ml, T[max] 4 hr, AUC[0-8] 2359.5 ng.hr/mlfor CP 934 HPMC [64], while C[max] 429.02 ng/ml, T[max] 2.67 hr, AUC[0-8] 1637.43 ng.hr/ml for Chitosan HPMC [64]. In comparison, in case of oral administration of control tablet the C[max] 591.28 ng/ml, T[max] 1.5 hr, AUC[0-8] 1869.29ng.hr/ml