Formulation and evaluation of limonene-based membrane-moderated transdermal therapeutic system of nimodipine.

The aim of the present study was to design a membranemoderated transdermal therapeutic system (TTS) of nimodipine using 2% w/w hydroxypropyl methylcellulose (HPMC) gel as a reservoir system containing 4% w/w of limonene as a penetration enhancer. The permeability flux of nimodipine through ethylene vinyl acetate (EVA) copolymer membrane was found to increase with an increase in vinyl acetate content in the copolymer (9 to 28%). The effect of pressure-sensitive adhesives such as TACKWHITE A 4MED® on the permeability of nimodipine through EVA membrane 2825 (28% w/w vinyl acetate) or membrane/rat skin composite also was studied. The permeability flux of nimodipine from the chosen EVA 2825 (with 28% vinyl acetate content) was 159.72 ± 1.96 μg/cm2/hr, and this flux further decreased to 141.85 ± 1.54 μg/cm2/hr on application of pressure-sensitive adhesive (TACKWHITE A 4MED®). However, the transdermal permeability flux of nimodipine across EVA 2825 membrane coated with TACKWHITE A 4MED®/rat skin composite was fo...