Supercritical Fluid Processing, Precipitation and Impregnation of Anti-Cancer Drugs with Bio-Polymer Films

Camptothecin together with Taxol have been demonstrated to be effective against a broad spectrum of tumors, improving the lives of cancer patients. However, due to their hydrophobicity, these drugs are not easily removed from blood circulation. As a result, the accumulation of toxic amounts creates side effects that far outweigh the therapeutic property. Compritol, a lipid particle, have been proposed as drug carrier, because it enhances the bioavailability, releases the active ingredient in a controlled form and protect the drug from light, moisture and oxidation.

Preliminary essays with acetaminophen and polyethylene glycol (PEG) were processed using supercritical fluids (SCFs). This technology has been successfully applied for the formation of micro particles; controlling particle size, avoiding thermal and chemical degradation of the active ingredient and providing better stability to particles of drug-lipids. The encapsulation was evaluated as a function of drug/lipid composition (25-75% wt.) using scanning electron microscopy (SEM). From these SEM images one can observe that the microspheres were embedded into the PEG matrix and the best homogeneity was obtained with the 50/50 mixture. One explanation for these results could be due to the hydrogen-bonding interactions and the size of PEG and acetaminophen. In addition, the SEM images reveal that particle size of pure acetaminophen with and without SCF processing did not show significant differences.