Extended release acetaminophen-hypromellose matrix tablet and the effect of insoluble additives on the drug release kinetics

摘要

Acetaminophen-hypromellose matrix tablet in the drug: polymer ratio of 20: 1 yielded an extended release profile. The effect of water insoluble excipients such as corn starch, pregelatinized starch and dicalcium phosphate on dissolution rate of acetaminophen from the matrix tablet was evaluated. Based on the first order rate constant, it was shown that water insoluble excipients reduced the rate of drug release from the tablet. The drug release was inversely related to the amount of waterinsoluble excipients in the formulation. Fitting power law functions to data, using nonlinear regression methods allowed estimation of the release exponent 'n' and revealed that waterinsoluble excipients shifted the mechanism of drug release from an anomalous transport towards Fickian diffusion.