title: Formulation and in vitro assessment of minoxidil niosomes for enhanced skin delivery.
abstract: Niosomes have been reported as a possible approach to improve the low skin penetration and bioavailability characteristics shown by conventional topical vehicle for minoxidil. Niosomes formed from polyoxyethylene alkyl ethers (Brij) or sorbitan monoesters (Span) with cholesterol molar ratios of 0, 1 and 1.5 were prepared with varying drug amount 20-50mg using thin film-hydration method. The prepared systems were characterized for entrapment efficiency, particle size, zeta potential and stability. Skin permeation studies were performed using static vertical diffusion Franz cells and hairless mouse skin treated with either niosomes, control minoxidil solution (propylene glycol-water-ethanol at 20:30:50, v/v/v) or a leading topical minoxidil commercial formulation (Minoxyl). The results showed that the type of surfactant, cholesterol and incorporated amount of drug altered the entrapment efficiency of niosomes. Higher entrapment efficiency was obtained with the niosomes prepared from Span 60 and cholesterol at 1:1 molar ratio using 25mg drug. Niosomal formulations have shown a fairly high retention of minoxidil inside the vesicles (80%) at refrigerated temperature up to a period of 3 months. It was observed that both dialyzed and non-dialyzed niosomal formulations (1.03+/-0.18 to 19.41+/-4.04%) enhanced the percentage of dose accumulated in the skin compared to commercial and control formulations (0.11+/-0.03 to 0.48+/-0.17%) except dialyzed Span 60 niosomes. The greatest skin accumulation was always obtained with non-dialyzed vesicular formulations. Our results suggest that these niosomal formulations could constitute a promising approach for the topical delivery of minoxidil in hair loss treatment.
authors.affiliation: College of Pharmacy, Yeungnam University, 214-1, Dae-Dong, Gyongsan 712-749, South Korea.
authors.forename: Prabagar
authors.initials: P
authors.lastname: Balakrishnan
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Shanmugam
authors.forename: Won Seok
authors.initials: WS
authors.lastname: Lee
authors.forename: Won Mo
authors.initials: WM
authors.lastname: Lee
authors.forename: Jong Oh
authors.initials: JO
authors.lastname: Kim
authors.forename: Dong Hoon
authors.initials: DH
authors.lastname: Oh
authors.forename: Dae-Duk
authors.initials: DD
authors.lastname: Kim
authors.forename: Jung Sun
authors.initials: JS
authors.lastname: Kim
authors.forename: Bong Kyu
authors.initials: BK
authors.lastname: Yoo
authors.forename: Han-Gon
authors.initials: HG
authors.lastname: Choi
authors.forename: Jong Soo
authors.initials: JS
authors.lastname: Woo
authors.forename: Chul Soon
authors.initials: CS
authors.lastname: Yong
mesh_terms: D000279:Administration, Cutaneous; D000818:Animals; D001682:Biological Availability; D002626:Chemistry, Pharmaceutical / Q000379:methods*; D016503:Drug Delivery Systems / Q000379:methods*; D066298:In Vitro Techniques; D008081:Liposomes; D051379:Mice; D008812:Mice, Hairless; D008914:Minoxidil / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D012869:Skin Absorption
chemical_list: D008081:Liposomes; D008914:Minoxidil