Buccoadhesive tablets of captopril were prepared by direct
compression of the drug with different polymers; Carbopol 934 (CP
934), Eudragit RS 100 (EU RS 100), Chitosan (Ch), Hydroxpropyl
methylcellulose (HPMC) and Polyvinylpyrrolidone K30 (PVP K30)
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 934:HPMC 6:4 and Ch:HPMC
6:4) 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: Cmax 506.9 ng/ml, Tmax 4 hr, AUC0-8 2359.5 ng.hr/ml for CP
934: HPMC (6:4), while Cmax 429.02 ng/ml, Tmax 2.67 hr, AUC0-8
1637.43 ng.hr/ml for Chitosan: HPMC (6:4). In comparison, in
case of oral administration of control tablet the Cmax 591.28 ng/ml,
Tmax 1.5 hr, AUC0-8 1869.29 ng.hr/ml.