DEVELOPMENT, IN-VITRO AND EX-VIVO EVALUATION OF MUCO-ADHESIVE BUCCAL TABLETS OF HYDRALAZINE HYDROCHLORIDE

Abstract

Hydralazine hydrochloride is an anti-hypertensive drug. The drug has poor oral bioavailability (BA) of about 30- 50% due to extensive first-pass metabolism. Hence, the buccal delivery was used to enhance the BA of hydralazine hydrochloride. Buccal muco-adhesive tablets were prepared by direct compression technique, using carbopol 934P, HPMC K₄M, sodium alginate and sodium carboxy methyl cellulose (NaCMC) as muco-adhesive polymers. Prepared formulations were evaluated for physico-chemical characterization, ex-vivo residence time and in-vitro release studies. The some of the parameters viz hardness, thickness, weight variation are showing the values within the pharmacopeial limits. However, the swelling and bio-adhesive strength were increased with increasing polymer concentrations. From the in-vitro release studies, F9 buccal tablets prepared with NaCMC exhibited better release (96.56%, 6 h) profile than all other formulations and considerd as optimized. The release mechanism from kinetic methods suggests that, the drug release follows zero-order kinetics with diffusion mechanism. Thus, the buccal tablets of hydralazine hydrochloride showed enhanced BA and were further confirmed by in-vivo studies.

Key Words:
Hydralazine hydrochloride. First-pass metabolism. Buccal muco-adhesive tablets. In- vitro; ex-vivo