Production of new hybrid systems for drug delivery by PGSS (Particles from Gas Saturated Solutions) process

The formulation of S-(+)-ibuprofen as a model water-insoluble drug in different carrier materials (poloxamers, gelucire and glyceryl monostearate, GMS) by Particles from Gas Saturated Solutions (PGSS) technique has been studied. Porous, spherical particles of 50⿿200 μm have been obtained with encapsulation efficiencies up to 90%. Differential scanning calorimetry assays reveal modifications on the structure of the material, with formation of a solid solution in experiments with poloxamer carriers, and formation of solid dispersions with a possible reduction of the crystallinity of the carrier in experiments with GMS. Drug release tests in simulated gastric and intestinal fluids have been performed. Formulations with poloxamer carrier materials provided an increased solubility of ibuprofen in the gastrointestinal fluids, with a very fast release and dissolution of this compound, while gelucire and GMS carriers did not improve the solubility of ibuprofen, but provided a slower, controlled release of the drug. PGSS-processed samples presented a superior performance over physical mixtures in terms of the solubility increase and the control of the release rate. These results show the wide possibilities and flexibility of the PGSS technique for the development of hybrid formulations of water-insoluble active compounds with hydrophilic or hydrophobic carrier materials, achieving either an increased, accelerated dissolution, or a slower, controlled delivery, depending on the choice of carrier materials.