Formulation and in vitro evaluation of pentazocine transdermal delivery system.

Author(s): Furuishi T, Io T, Fukami T, Suzuki T, Tomono K

Affiliation(s): Research Unit of Pharmaceutics, College of Pharmacy, Nihon University, Chiba, Japan.

Publication date & source: 2008-07, Biol Pharm Bull., 31(7):1439-43.

Publication type: Research Support, Non-U.S. Gov't

The aim of this study was to prepare a pentazocine (PTZ) matrix-type transdermal drug delivery system (TDDS) using acrylic pressure-sensitive adhesives. Among the five Duro-Tak adhesive polymers tested (87-9301, 87-2677, 87-201A, 87-2196, 87-2852), in vitro dissolution studies demonstrated the highest PTZ release flux from the Duro-Tak 87-9301 matrix. In addition, the effects of permeation enhancers, isopropyl myristate (IPM) and glyceryl monocaprylate (GEFA-C(8)), and drug content on PTZ skin permeation from prepared patches were evaluated using Franz diffusion cells fitted with hairless mouse skin. IPM and GEFA-C(8) were found to produce effective flux of PTZ at a patch concentration of 10% w/w and 5% w/w, respectively. The PTZ flux increased linearly as the loading dose increased up to 30%, whereas no further increase in flux was observed at loading doses of 40% and 50% due to drug crystallization in the matrix. Thus, the highest skin permeation rate (24.2 microg/cm(2)/h) was achieved when 30% of PTZ was loaded in Duro-Tak 87-9301 with 10% IPM and 5% GEFA-C(8). These results demonstrate the feasibility of a novel narcotic-antagonist analgesic matrix-type TDDS for PTZ.