New sustained release of zidovudine matrix tablets - cytotoxicity toward Caco-2 cells.

Objective: The aim of this study was to adjust the zidovudine (AZT) release from solid tablets to an ideal profile, by developing matrices comprising swellable polymers with nonswellable ones.

Methods: Directly compressed matrices comprised different ratios of hydroxypropylmethylcellulose K15M and K100M, ethylcellulose, and methacrylic acid (Eudragit(®) RS PO and Eudragit(®) RL PO) were prepared. Technological characterization and evaluation of the in vitro release behavior were carried out.

Development and validation of a RP-HPLC method for the determination of zidovudine and its related substances in sustained-release tablets.

A reversed-phase high-performance liquid chromatography (RP-HPLC) method for the rapid and accurate quantification of zidovudine (AZT) in sustained release tablets during stability testing was developed. A Waters RP-18 XTerra™(®) column, using a water:methanol (80:20, v/v%) mobile phase at a flow rate of 1.0 ml min(-1), and UV detection at 266 nm, was employed.

The influence of the compression force on zidovudine release from matrix tablets.

The aim of the present work is the study of different zidovudine (AZT) formulations containing polymers (both cellulosic and acrylic), in order to evaluate the influence of the compression force on the antiviral release from the matrix tablets. The results evidenced that the formulations compressed at 500 and 1,000 MPa exhibit a higher hardness than those prepared at 100 MPa. The effect of the compression force on the drug release was analyzed and a statistically significant difference was observed (P < 0.