Formulation and evaluation of pulsatile release tablets of Venlafaxine Hydrochloride

S. Masood Ahmed*, G. Somasekhar, R. Nazemoon, S. MD. Razia Sultana
Department of Pharmaceutics, Safa College of Pharmacy, Kurnool, Andhra Pradesh, India

A B S T R A C T
Conventional tablet dosage form of venlafaxine HCl has a poor pharmacokinetic profile and shorter half life (5hrs) that necessitates 2-3 times daily dosing. Thus, this study attempts to design and evaluate a chronomodulated pulsatile drug delivery system of venlafaxine by rupturable coating method. The core containing venlafaxine were prepared by direct compression method and then coated sequentially with an inner swelling layer containing superdisintegrants like sodium starch glycollate, crosscaramellose, and an outer rupturable layer consisted of Eudragit L 100 and ethyl cellulose and HPMC E-15. In vitro drug release and rupture tests were performed using USP paddle method at 50 rpm in 0.1 N HCl and phosphate buffer of pH 6.8. The results show that as the amount of inner swelling layer increases the lag time decreases and as the Eudragit coating level prolongs the lag time and percent water uptake of time dependent pulsatile release system decreases.
Keywords: pulsatile drug delivery, eudragit, venlafaxine HCl, HPMC