title: The effects of fatty acids in propylene glycol on the percutaneous absorption of alendronate across the excised hairless mouse skin.
abstract: The effects of fatty acids at various concentrations in propylene glycol (PG) on the in vitro permeation of alendronate from solution formulations and formulated pressure-sensitive adhesive (PSA) transdermal delivery systems through excised hairless mouse skin were investigated. Caprylic acid, capric acid, lauric acid, oleic acid and linoleic acid at concentrations of 3, 6 and 10% were employed as a fatty acid. The highest maximum permeation flux was obtained with 3% capric acid in PG followed by 6% capric acid and 3% oleic acid from solution formulations; the enhancement factor by the addition of 3% capric acid to PG was 20.5 compared to PG alone. On the contrary, from PSA transdermal delivery systems, the highest enhancement factor of 2.9 was attained with 6% caprylic acid in PG compared to PG alone. The maximum permeation flux and lag time from PSA transdermal delivery systems by the addition of 6% caprylic acid to PG were 195.68+/-26.6 ng/cm2/h and 0.6+/-0.3h whereas PG without fatty acids showed 67.3+/-5.8 ng/cm2/h and 0.5+/-0.4h, respectively. The PSA transdermal delivery systems initially provided very high permeation rate followed by a gradual decrease regardless of the fatty acids. The highest release rate was also obtained with the formulation containing 6% caprylic acid in PG although release rates were not matched with permeation rates perfectly. In conclusion, for effective transdermal delivery system of alendronate, 6% caprylic acid in PG could be employed.
authors.affiliation: College of Pharmacy, Ewha Womans University, 11-1 Daehyun-Dong Seodaemun-Gu, Seoul 120-750, Republic of Korea.
authors.forename: Ahyoung
authors.initials: A
authors.lastname: Choi
authors.forename: Hyesil
authors.initials: H
authors.lastname: Gang
authors.forename: Inkoo
authors.initials: I
authors.lastname: Chun
authors.forename: Hyesun
authors.initials: H
authors.lastname: Gwak
mesh_terms: D000279:Administration, Cutaneous; D019386:Alendronate / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D000818:Animals; D050071:Bone Density Conservation Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D016503:Drug Delivery Systems; D005227:Fatty Acids / Q000737:chemistry*; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008812:Mice, Hairless; D014677:Pharmaceutical Vehicles; D019946:Propylene Glycol / Q000737:chemistry*; D012869:Skin Absorption; D012995:Solubility
chemical_list: D050071:Bone Density Conservation Agents; D005227:Fatty Acids; D014677:Pharmaceutical Vehicles; D019946:Propylene Glycol; D019386:Alendronate