Preparation of starch/cellulose acetate structures as drug delivery system using green technology

Controlled drug delivery systems, using biocompatible or biodegradable polymers, have received considerable attention in the last years. These substances are generally used for the preparation of controlled release formulations, which therefore allow control the rate of assumption of the drug by the body improving its pharmocinetic profile. The objective of this work is to integrate some principles of green technology combining the processing of starch based polymers using ionic liquids as a green solvent together with supercritical fluid technology (SCF) to develop new products for drug delivery applications. Starch based polymers present an enormous potential to be used in biomedical field due to their biocompatibility, renewability and sustainability. However, due to the poor solubility they are extremely difficult to be dissolved in water or organic solvents. This can be overcome using ionic liquids which are recognized as green recyclable solvents to solubilize natural polymers, such as cellulose, lignocellulosic materials, starch, chitin and chitosan. One of the main advantages of using this processing method is the possibility to impregnate active compounds in a subsequent step, after the preparation of the structures. Supercritical fluids, such as (scCO2) has been identified as prime candidates to develop alternative clean processes for the preparation of drug-loaded polymeric matrixes.