Abstract

FORMULATION, CHARACTERIZATION AND EVALUATION OF SUSTAINED RELEASE NIFEDIPINE CAPSULE.

Kanika Arora*,Meenu Nagpal, Upendra K. Jain, R. C. Jat, Dr.Suman Jain

Abstract

The present work was aimed at exploitation of hydrophobic polymer Ethyl Cellulose for sustained delivery of Nifedipine, further, at achieving sustained release for the period of 12 hours. Five different formulations of nifedipine matrix granules with different amounts of the polymer ethyl cellulose and drug in the ratio of 1:1, 2:1, 3:1, 4:1 and 5:1 were prepared by wet granulation and the resultant granules were filled in size „2‟ hard gelatin capsules. The FT-IR spectra of the pure drug and formulation F3 indicated no chemical interactions between the drug and carrier used. The resultant granulations exhibited acceptable particle size distribution and good flow properties. Capsules prepared by using these granulations exhibited desirable pharmacotechnical properties. The average particle size of granules was found to be in the range of 500-841μm. The results of dissolution study of formulations F1, F2, F3, F4, F5 showed 84.77% in 6 hrs, 89.63% in 8 hrs, 89.57% in 12 hrs, 58.96% in 12 hrs and 52.14% in 12 hrs respectively. And therefore, formulation F3 with drug – polymer ratio 1:3 was found to be most promising formulation as it showed sustained release (89.57%) as well as maintained excellent matrix integrity during the period of 12 hr study. The optimized formulation (F3) selected from the % drug release profiles was fitted into various kinetic models to know the mechanism of drug release from this formulation. The best fit release kinetic model was found to be Higuchi for F3, which indicated release of the drug by difussion from matrix type formulation. Drug release study supported the study hypothesis that as a result of formation of a nifedipine molecular dispersion, nifedipine dissolution inside the matrix was no longer the rate-limiting step for drug release, and the drug diffusion in matrix through the channels formed by dissolution of lactose became the slowest step instead. Indeed, the results offered formulation researcher a cheaper option that incurs no additional cost that may arise if a material is to be replaced because of the need to improve on response parameters such as dissolution and drug release. The results of the present study indicate that the granules prepared using ethyl cellulose could be used for the sustained release of the drug. Therefore, it was also concluded that Ethyl cellulose can be successfully used to modulate drug release of poorly water soluble drug Nifedipine in sustained release inert matrices.

Keywords: Nifedipine, sustained – release, ethyl cellulose, molecular dispersion, enhanced solubility.