title: Effect of emulsifiers and their liquid crystalline structures in emulsions on dermal and transdermal delivery of hydroquinone, salicylic acid and octadecenedioic acid.
abstract: This study investigated the effect of emulsifiers and their liquid crystalline structures on the dermal and transdermal delivery of hydroquinone (HQ), salicylic acid (SA) and octadecenedioic acid (DIOIC). Emulsions containing liquid crystalline phases were compared with an emulsion without liquid crystals. Skin permeation experiments were performed using Franz-type diffusion cells and human abdominal skin dermatomed to a thickness of 400 mum. The results indicate that emulsifiers arranging in liquid crystalline structures in the water phase of the emulsion enhanced the skin penetration of the active ingredients with the exception of SA. SA showed a different pattern of percutaneous absorption, and no difference in dermal and transdermal delivery was observed between the emulsions with and without liquid crystalline phases. The increase in skin penetration of HQ and DIOIC could be attributed to an increased partitioning of the actives into the skin. It was hypothesized that the interaction between the different emulsifiers and active ingredients in the formulations varied and, therefore, the solubilization capacities of the various emulsifiers and their association structures.
authors.affiliation: Unit for Drug Research and Development, North-West University, Potchefstroom Campus, Potchefstroom, South Africa.
authors.forename: A
authors.initials: A
authors.lastname: Otto
authors.forename: J W
authors.initials: JW
authors.lastname: Wiechers
authors.forename: C L
authors.initials: CL
authors.lastname: Kelly
authors.forename: J C
authors.initials: JC
authors.lastname: Dederen
authors.forename: J
authors.initials: J
authors.lastname: Hadgraft
authors.forename: J
authors.initials: J
authors.lastname: du Plessis
mesh_terms: D000279:Administration, Cutaneous; D003460:Crystallization; D003998:Dicarboxylic Acids / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004655:Emulsions; D005079:Excipients / Q000737:chemistry*; D005260:Female; D006801:Humans; D006873:Hydroquinones / Q000008:administration & dosage / Q000493:pharmacokinetics*; D066298:In Vitro Techniques; D010539:Permeability; D020156:Salicylic Acid / Q000008:administration & dosage / Q000493:pharmacokinetics*; D012869:Skin Absorption; D012995:Solubility
chemical_list: D003998:Dicarboxylic Acids; D004655:Emulsions; D005079:Excipients; D006873:Hydroquinones; C528535:octadecenedioic acid; D020156:Salicylic Acid; C031927:hydroquinone