FORMULATION AND EVALUATION OF MUCOADHESIVE BUCCAL TABLETS OF LABETALOL HYDROCHLORIDE

Arigela Bharathi*, Nadikatla Anusha, Vaida Aswini priya, Sali Roja, Garikipati Priyanka

ABSTRACT

The present study was aimed to formulate and evaluate nine prototype formulations (Viz.: F1 to F9) of Labetalol hydrochloride mucoadhesive buccal tablets using various concentrations of mucoadhesive polymers such as HPMC K4M, Locust bean gum and Tara gum, individually and in combination by direct compression method. Objective of the study is to achieve prolonged drug release and improve the bioavailability by avoidance of first-pass hepatic metabolism. Prepared buccal tablets were comparatively evaluated for their physicochemical parameters like weight variation, hardness, friability and drug content. The surface pH, swelling index, bio-adhesive strength are also carried out which has been important aspect for success of mucoadhesive buccal tablets. FTIR studies showed no evidence on interactions between drug and polymers. The swelling of all the formulations was increased as the time proceeds. The in vitro drug release of Labetalol hydrochloride was performed under sink conditions (Phosphate buffer pH 6.8, 37±0.5ºC, 50rpm) using type II dissolution apparatus for 12hrs. Formulation F5 (Combination of HPMC K4M and Tara gum at 25%w/w concentration) is considered as optimized formulation with the best in vitro drug release and high bio-adhesive strength i.e. 52.74% and 15g respectively. Mathematical treatment of the in vitro drug release data suggests that, all the formulations fitted into first order release kinetics. Drug release from the matrix occurred by combination of two mechanisms, diffusion of drug from tablet matrix and anamolous transport, which was reflected from Higuchi's model and Korsmeyer peppas equation.

Keywords: Labetalol hydrochloride, HPMC K4M, Locust bean gum, Tara gum, Mucoadhesive buccal tablets.