Optimising the release of aspirin from an inert ethyl cellulose-based matrix

The goal of this study was to investigate how hydrophilic and hydrophobic excipients affected the dissolution profile in order to get the most out of aspirin's long-term release from an inert ethylcellulose-based matrix. The hypothesis evaluated was that a mixture design methodology could precisely forecast and enhance drug release kinetics predicated based on excipient interactions. A special cubic mixture design was used to make experimental formulations. It comprised three variable factors: aspirin, lactose (a hydrophilic excipient that enhances aqueous solubility and promotes drug release), and zinc stearate (a hydrophobic excipient that retards wettability and slows drug diffusion. Ethylcellulose was kept at 3%. The powders were mixed for 10 minutes at 30 rpm, then wet granulated. After that, they were dried at 45°C for 12 hours and sieved to keep the 1250 μm fraction. The USP basket method was used to test dissolution at 50 rpm in an acetate buffer with a pH of 4.5. Statgraphics Centurion software was used to fit a special cubic model to the data. The results showed that the proportions of the excipients had a big effect on the release kinetics, for example, lactose sped up the release rate, while zinc stearate slowed it down by making barriers that water couldn't get through. The special cubic model worked well (adjusted R2 > 0.85), which made it possible to accurately predict dissolution profiles. The results of the optimization showed that increasing the amount of zinc stearate is a good way to keep aspirin from being released too quickly. The mixture design approach proved effective in modulating and optimising the release of aspirin from an ethylcellulose-based matrix. The conclusion was made that sustained-release dosage forms could be reproduced and improved in a logical way using statistical modelling.