Modelling of controlled drug release in gastrointestinal tract simulation

Abstract

The drug release system is a process in which a bioactive substance discharged from a drug product and enters the process of absorption, distribution and metabolism to deliver its pharmacological action. The drug release is maintained at a specific rate to maximize the benefits as well as to suppress the side impacts. The release rate behaviour is affected by physiological conditions such as ion charge, pH level and enzymatic environment. Since the intestinal tract itself varies broadly in a pH environment, hence it is important to study the profile of drug release in different pH conditions. Mathematical model turns out very useful in predicting the drug release as well as reducing experimental works. The objective of this work was to study the mathematical model in describing the drug release profile in gastrointestinal tract liquid simulation. The release profiles of furosemide and sodium-iron chlorophyllin encapsulation were studied in the pH ranges 1.3-1.5 and 6.8-7.4 to simulate the different part of gastrointestinal tract acidity. The Korsemeyer-Peppas, Weibull and Gompertz were applied in describing the profile. Korsmeyer-Peppas model shows more superior (R2>0.912) than Weibull and Gompertz in describing the release kinetic of furosemide and sodium-iron chlorophyllin encapsulations in both pHs of GTS. The n values of Korsmeyer-Peppas are mostly less than 0.5 suggesting the release mechanism was governed by diffusion.