COMPARATIVE-STUDY ON THE RELEASE KINETICS OF METHYL-NICOTINATE FROM TOPIC FORMULATIONS

An in vitro method for the determination of methyl nicotinate (MN) delivery from topical dosage forms, using a Franz diffusion cell system and artificial membranes, is described. Four different MN containing formulations for the topical treatment of the so-called 'cellulitis' were designed. The vehicle influence on MN release has been studied utilizing a composite membrane system especially designed in order to reproduce the barrier properties of the skin stratum corneum (SC). The artificial membranes composed of silicone and cellulose esters were previously tested with MN aqueous solutions. Single and composite membrane permeability coefficients were measured and compared with those of excised human skin. It is suggested that human skin permeability of MN may be predicted by using a particular multilaminated membrane system. The MN permeability coefficients of the different topical dosage forms were determined employing the designed synthetic membrane system. Among the different vehicles, MN retains the highest penetration rate when incorporated into the hydrophilic gel, indicating that polymers based hydrophilic gels can be efficiently employed for design, production and in vitro tests of topical forms suitable for the in vivo treatment of dermatological diseases.