Supercritical impregnation of acetylsalicylic acid in yeast β-glucan aerogels

Aerogels are solid materials with low density, high porosity and high surface area, which make them interesting for drug delivery of active compounds and tissue engineering applications.[1] To achieve the requirements of low toxicity, biodegradability and stability for drug delivery applications, polysaccharides, like β-glucans, represent a good option as carriers.[2] The supercritical impregnation is a technique explored to solve problems of formulation and development of drug delivery systems. This technique allows a good solubility of the active compounds and diffusion through the aerogel and at the same time preserves the structure of the aerogel, providing a homogeneous distribution of the drug in the material.[3] In previous work, barley and yeast β-glucans aerogels were synthetized and characterized by different techniques. In this work, yeast β-glucan aerogels were used for supercritical impregnation of an active compound, such as acetylsalicylic acid. Then with these impregnated aerogels we could evaluate the impregnation yield of the active compound in different operating conditions of pressure (8, 12, 16 and 20 MPa) and temperature (35ºC, 40ºC and 50ºC) and estimate the in vitro release of the acetylsalicylic acid in the different aerogels, that we observed to be faster in the first 2 hours.