Production of polymer/active compound composites by supercritical CO2 assisted processes

Abstract

The interest in the production of novel polymer/active compound composites has increased over time as a response to the main issues encountered in the pharmaceutical field. Nowadays, polymeric carriers are employed to prepare composite systems with several aims, including the protection or stabilization of an active compound, as well as masking its unpleasant taste or odor. However, the main challenge is to reach a control of the drug release rate from innovative pharmaceutical forms, overcoming the drawbacks associated to the use of conventional formulations. The latter ones often provide uncontrolled drug release, sometimes out of the therapeutic range; as a consequence, high and repeated drug dosages are necessary, leading to serious side effects on the patient’s health. Different formulations can be fabricated as drug delivery systems, such as granulates, tablets or topical patches. However, the technologies generally used to produce composites suffer from some drawbacks, including the possible degradation of the active compound due to the high operating temperature, or multistage processing required to remove organic solvents, whose residues are often not negligible in the final composites. Supercritical carbon dioxide (scCO2) assisted techniques are considered a good alternative to overcome all the main limits involved in the use of traditional processes. In this Ph.D. work, two scCO2 assisted processes are proposed to produce different polymer/active compound composites: - Supercritical AntiSolvent (SAS) technique, to produce composite powder with a microparticle-like morphology; - supercritical impregnation, to obtain orally disintegrating tablets (ODTs) or topical patches. The main goal is to accelerate or to slow down the dissolution rate of the active principle contained in the composites, depending on the therapeutic effect required by a specific application. ... [edited by Author]