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 < 0.05). Using lower compression forces leads to slightly better release profiles, i.e., profiles close to an ideal Higuchi kinetics for a total release of drug in a 12-h period, allowing to conclude that a compression force higher than 100 MPa is unnecessary.