title: Self-dissolving micropiles for the percutaneous absorption of recombinant human growth hormone in rats.
abstract: The feasibility of self-dissolving micropiles (SDMP) as a percutaneous delivery system of recombinant human growth hormone (rhGH) has been studied in rats using SDMP where dextran was used as a base. After mixing dextran solution with rhGH, SDMPs were prepared by pulling with polypropyrene tips. The mean weight, length and diameter were 0.68+/-0.05 mg, 3.2+/-0.5 mm and 0.6+/-0.2 microm, respectively. To evaluate the bioavailability (BA) of rhGH percutaneously administered by SDMP, an absorption experiment was performed in rats. RhGH SDMPs were inserted into the rats skin, 200 microg kg(-1), and plasma rhGH levels were measured by an ELISA method. Peak plasma rhGH level, 132.8+/-11.8 ng ml(-1), appeared at 0.8+/-0.2 h. By comparing the plasma rhGH levels vs. time profiles after the administration of SDMP and intravenous injection of rhGH solution, 5 microg kg(-1), BA of rhGH from SDMP was calculated to be 87.5%. Theses results may suggest that SDMP can be used as a novel percutaneous drug delivery system.
authors.affiliation: Department of Pharmacokinetics, Kyoto Pharmaceutical University, Kyoto, Japan. yukako@mb.kyoto-phu.ac.jp
authors.forename: Yukako
authors.initials: Y
authors.lastname: Ito
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ohashi
authors.forename: Keiji
authors.initials: K
authors.lastname: Shiroyama
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Sugioka
authors.forename: Kanji
authors.initials: K
authors.lastname: Takada
mesh_terms: D000818:Animals; D019540:Area Under Curve; D004797:Enzyme-Linked Immunosorbent Assay; D006207:Half-Life; D019382:Human Growth Hormone / Q000097:blood / Q000493:pharmacokinetics*; D007275:Injections, Intravenous; D008297:Male; D053758:Nanoparticles; D051381:Rats; D017208:Rats, Wistar; D011994:Recombinant Proteins / Q000097:blood / Q000493:pharmacokinetics; D012869:Skin Absorption / Q000502:physiology*
chemical_list: D011994:Recombinant Proteins; D019382:Human Growth Hormone