Controlled Release Matrix Tablets of Zidovudine: Effect of Formulation Variables on the <Emphasis Type="BoldItalic">In Vitro</Emphasis> Drug Release Kinetics |
| |
Authors: | Punna Rao Ravi Udaya Kanth Kotreka Ranendra Narayan Saha |
| |
Institution: | (1) Pharmacy Group, Birla Institute of Technology and Science, Pilani, Rajasthan, India |
| |
Abstract: | The purpose of this research was to design oral controlled release (CR) matrix tablets of zidovudine (AZT) using hydroxypropyl
methylcellulose (HPMC), ethyl cellulose (EC) and carbopol-971P (CP) and to study the effect of various formulation factors
on in vitro drug release. Release studies were carried out using USP type 1 apparatus in 900 ml of dissolution media. Release kinetics
were analyzed using zero-order, Higuchi’s square root and Ritger–Peppas’ empirical equations. Release rate decreased with
increase in polymer proportion and compression force. The release rate was lesser in formulations prepared using CP (20%)
as compared to HPMC (20%) as compared to EC (20%). No significant difference was observed in the effect of pH of dissolution
media on drug release from formulations prepared using HPMC or EC, but significant difference was observed in CP based formulations.
Decrease in agitation speed from 100 to 50 rpm decreased release rate from HPMC and CP formulations but no significant difference
was observed in EC formulations. Mechanism of release was found to be dependent predominantly on diffusion of drug through
the matrix than polymer relaxation incase of HPMC and EC formulations, while polymer relaxation had a dominating influence
on drug release than diffusion incase of CP formulations. Designed CR tablets with pH independent drug release characteristics
and an initial release of 17–25% in first hour and extending the release up to 16–20 h, can overcome the disadvantages associated
with conventional tablets of AZT. |
| |
Keywords: | controlled release matrix tablets release kinetics zidovudine |
本文献已被 PubMed SpringerLink 等数据库收录! |
|