Development and Evaluation of Multi-Layer Controlled Release Tablet of Pentoxifylline

K. Sunil Kumar*¹, M. Lokesh^2
1Associate Professor, Department of Pharmaceutics, Sun Institute of Pharmaceutical Education and Research, Kakupalli, Nellore, Andhra Pradesh, India.
²Sun Institute of Pharmaceutical Education and Research, Kakupalli, Nellore, Andhra Pradesh, India.

A b s t r a c t
In the present study an attempt was made to prepare Pentoxifylline Extended release tablet for the treatment of Peripheral artery disease. The drug excipient compatibility study was done and found to have no interactions. The precompression parameters (bulk density, tap density, Carrs index, and angle of repose) of the prepared tablets were within the ranges given by official standards, indicating that the physical mixture was found to be free-flowing. In vitro dissolution studies were done for Felodipine Extended release tablet prepared with different concentration of polymer HPMC K4M low viscosity grade and HEC high viscosity grade. Formulation F8 was found to be 94.75% drug release at the end of 12th hours which was within the USP limits. The kinetic of drug release for formulation F8 was calculated and plotted. The formulation F8 follows zero order release kinetics and the drug release mechanism was found to be non-fickian (anomalous) diffusion. The optimized formulation was compared with marketed product and showed similar release profile. The optimized tablets, F8 were selected for stability studies were carried out according to ICH guidelines at 40ºC /75 % RH for a specific time period indicated that the physical parameters and drug release characteristics were not altered significantly showing good stability on storage. The formulation containing 8% of polymer (6% of HPMC K4M and 2% of HEC) (F8 batch) followed the desired release profile and selected for further studies. The optimized formulation follows zero order release pattern (R2.9942 with rate of release 7%/hr) and the drug release mechanism was non-fickian (anomalous transfer). Therefore, swelling and diffusion mechanisms were found to be responsible for the prolonged release of pentoxifylline from formulated matrix tablets. The optimized formulation compared with marketed formulation, were found to have a similar In vitro release profile, which is confirmed by f1 and f2 values. In terms of physical properties and drug content, the formulation (F8) was found to be stable for 3 months under accelerated conditions
Keywords: Pentoxifylline, ICH guidelines, HPMC K4M, Carrs index