Proniosomal powders of natural canthaxanthin: Preparation and characterization.

In this study, canthaxanthin (CTX) was produced by Dietzia natronolimnaea HS-1 using beetroot molasses as substrate and used for encapsulation in proniosome powders after extraction, with the aim of improving its stability. Proniosome powders were prepared with an equimolar ratio of span 60/cholesterol and four different carriers, namely maltodextrin, mannitol, lactose and pullulan. The properties of these formulations as both proniosomal powders and resulted niosomal dispersions were evaluated. The type of carriers had significant effects on the micrometric properties of proniosome powders which were further confirmed by the results of SEM analysis. Although light and high temperatures affected the stability of CTX drastically, but encapsulation in proniosomes retarded its degradation. Among these samples, mannitol based proniosome powder (MAPP) produced small vesicles (mean diameter=175±3nmand polydispersity index=0.28±0.02) with the highest entrapment efficiency (74.1±2.7%). MAPP provided a promising formulation to increase CTX stability especially upon storage at high temperatures (45°C).