| Finasteride is medicine approved by the U.S. Food and Drug Administration for the treatment of male pattern hair loss. It is currently available as tablets for oral administration and its most common side-effects reported are decreased libido and impotence. Transfollicular application of finasteride proniosomes could reduce such side effects. The purpose of this study was to develop finasteride proniosomes for hair growth stimulation. Finasteride proniosomes were prepared by coacervation phase separation method. A Central composite design of response surface methodology was used to optimize formulation parameters of finasteride proniosomes. Results showed the optimum formulation was 39.03 % of cholesterol concentration of total lipid concentration, 20.26 mM of total lipid content, and 3.39 mM of finasteride concentration. The experimental values of the optimized formulation exhibited encapsulation efficiency of 94.47 ± 1.67 %, drug loading capacity of 13.14 ± 0.18 % and mean particle size of 292 ± 0.85 nm. Particles size and zeta potential of the system remained stable after 4 months storage at 4 º C, 25 º C 75% RH and 40 º C 75% RH. Percentage of encapsulation efficiency and drug loading capacity at 25 º C 75% RH was 86.69 ± 1.04 and 12.70 ± 0.08, respectively which was higher than those kept at 4 º C and 40 º C 75% RH. In vitro drug release study by dialysis test found that the drug release from proniosomes was in a sustained release manner. Skin penetration of finasteride investigated by Franz diffusion cell from finasteride proniosomes and finasteride solution at 24 hours were 5.26 ± 1.85 μg/cm2 and 2.51 ± 0.45 μg/cm2, respectively. In vitro transfollicular of finasteride proniosomes compared with finasteride solution showed amount of finasteride penetrated through transfollicular was 2.43 ± 0.63 μg/cm2 and 0.67 ± 0.91 μg/cm2, respectively. Investigation of hair growth in C57BL/6Mlac mice of 1% finasteride proniosomes was comparable to 2% minoxidil solution. The one percent finasteride proniosomes enhanced the hair growth stimulation more pronounced than that of finasteride solution of the same finasteride concentration. Histological evaluation of hair cycles after application of treated group showed that finasteride proniosomes and mioxidil solution significantly increased the number and size of hair follicle. Finasteride proniosomes significantly increased the number of hair follicle than finasteride solution. The skin irritation test showed a primary irritation index of zero. Therefore, the development of finasteride proniosomes for enhanced through transfollicular for the treatment of hair loss is one of the most interesting technologies that can reduce the side effects of the drug. |