Green processing: CO2-induced glassification of sucrose octaacetate and its implications in the spontaneous release of drug from drug-excipient composites

Abstract Liquid and supercritical (sc) CO2 offer tremendous advantages as a greener and safer solvent platform for the pharmaceutical industry. Sugar acetates form a class of inexpensive, carbonyl-based, CO2-philes that exhibits remarkably high solubility in liquid and scCO2. In this work, we combine the use of the green CO2 solvent platform and a class of renewable, FDA-approved excipient systems, viz., α- d -glucose pentaacetate (AGLU) and sucrose octaacetate (SOA), to disperse two active pharmaceutical ingredients, viz., aspirin and paracetamol. When treated with CO2, these excipients undergo profound structural modifications in comparison to those processed using two conventional organic solvents, viz., ethyl acetate and acetone. Of particular interest is the glass formation of sucrose octaacetate. Spontaneous drug release from these excipient systems processed using CO2 and the conventional solvents are compared. It is observed that the drug release from the CO2-processed SOA/drug system is an order of magnitude slower as compared to those processed using conventional solvent systems studied, plausibly due to the immobilization of the drug inside the glassy SOA matrix.