Formulation and evaluation of vesicular carrier systems containing anti alopecia serenoa repens extract

Androgenic Alopecia is primarily caused by dihydrotestosterone, which is mediated by 5- reductase enzyme. This can be reasonably treated by a 5-α reductase inhibitor. Serenoa repens, commonly known as "Saw Palmetto", extract has shown inhibitory activity against 5- reductase enzyme, which is believed to be due to the presence of many 5- reductase inhibiting components, mainly, methyl laurate. Methyl laurate (ML) has significant activity against both isotypes of 5α-reductase enzyme. The nature and size of niosomes make them great carriers for these anti-alopecia agents to aid deeper penetration and longer residence in the follicular sink. Niosomes were prepared using Span 60, Tween 60, and cholesterol with the addition of sodium cholate to increase the elasticity of the vesicles by thin-film hydration method. The thin films of these components together with either methyl laureate or Saw Palmetto extract were hydrated by pH 5.5-phosphate buffer saline (PBS). The average size of vesicles was 185 and 176 nm for methyl laurate and the Saw Palmetto (SP) extract vesicles, respectively. Their polydispersity indexes were 0.4 and 0.3, respectively, indicating homogeneity. Zeta potential values for these vesicles were -17.3 and -17.8 mV whereas their deformability indexes were 0.89 and 1.06, respectively. Two mg of ML could be loaded for every 0.1 mM surfactant. These vesicles exhibited acceptable stability over 6-month period. Methyl laureate loaded vesicles were subjected to permeability testing through a skin alternative artificial membrane, Strat-M, and showed significant flux (P= 0.0087), permeability (P=0.0075), and cumulative permeability (P=0.0007). Finally, loaded niosomes were incorporated into carboxymethyl cellulose gel formulation with a final concentration of 0.1 % (w/w). Rheograms of gel formulations showed a plastic behavior. The plastic viscosities of these gels were 9.27-9.44 centiPoise (cP). In conclusion, niosomes are applicable delivery carriers for anti-alopecia agents Saw Palmetto extract and its component methyl laurate, and are good candidates for in vivo efficacy assessment