Curcumin-loaded solid lipid particles by PGSS technology

Curcumin is a poorly water-soluble and fragile compound that, by virtue of its biological activities, has been considered for a variety of therapeutic applications. In this work, a novel process based on supercritical fluid technology has been used for encapsulating curcumin in solid lipid particles (SLP) to yield curcumin formulations with enhanced biopharmaceutical properties. SLP were obtained by a Particles Generated from Gas Saturated Solution technique (PGSS), where [tristearin + soy phosphatidylcholine (PC)]/[dimethylsulfoxide (DMSO) + curcumin] mixtures were processed. The effects of operative conditions were investigated in order to identify the main parameters that affect the biopharmaceutical properties of the final product. Samples with (tristearin + PC)/(DMSO + curcumin) w/w ratios ranging from 65.6:1 to 3:1 were prepared either in the presence or absence of helium and then processed by PGSS. The drug loading yield was found to be between 30 and 87 drug/lipid w/w%. The particles obtained from lipid mixtures with low DMSO feed were homogeneous in size. The formulation prepared with the highest DMSO feed yielded a bimodal particle size distribution with significant aggregation. Interestingly, the use of helium in the preparation of the lipid mixture was found to improve the biopharmaceutical properties of the SLP, namely drug loading and particle dimensional features. The preparation process was not found to degrade curcumin indicating that PGSS can be properly set-up for the preparation of curcumin lipid particles.