Effect of Penetration Enhancers on Transdermal Absorption of Insulin Across Human Cadaver Skin (original) (raw)

1994, Drug Development and Industrial Pharmacy

Materials PF was purchased from Clariant Corp. (Muttentz, Switzerland). Stearic acid (SA) was obtained from Kanto Chemical Co., Ltd. (Tokyo, Japan). Acetonitrile, ethanol, methanol, oleic acid (OA), sodium dodecyl sulfate (SDS), propylene glycol (PG), isopropyl myristate (IPM), L(Ϫ)-menthol (MEN), D(ϩ)-limonene (LIM) and phosphoric acid were purchased from Wako Pure Chemical Industries, Ltd. (Osaka, Japan) as the purest grade available. Macrogol 400 (MG) was of Japanese Pharmacopoeia (JP) grade. Sucrose fatty acid esters were obtained from Mitsubishi-Kagaku Foods Corporation (Tokyo, Japan). We used four kinds of sucrose fatty acid esters (L595, L1695, O1570 and S1570). L, O and S indicate lauric acid, oleic acid and stearic acid, respectively. The hydrophilic lipophilic balance (HLB) values of L595, L1695, O1570 and S1570 were 5, 16, 15 and 15, respectively. All other chemicals were obtained commercially as the purest grade available. Animals Male Sprague-Dawley rats weighing approximately 200-220 g were purchased from Tokyo Laboratory Animals Science Co., Ltd. (Tokyo, Japan). The experimental protocol was approved by the Ethics Review Committee for Animal Experimentation of Hoshi University. The guidelines for animal experimentation at Hoshi University conform to the basic guidelines published by the Ministry of Education, Culture, Sports, Science and Technology of Japan. In Vitro Transdermal Permeation Experiments After sacrifice using ether, the abdominal hair was removed using an electric clipper, and the abdominal skin was excised and mounted on flow-through Franz diffusion cells. 18) The exposed skin area was 0.785 cm 2 and test solutions (0.5 ml)