Metronidazole Delivery: An analysis of enhancers agents and their toxicity

The objective of the present work was to evaluate the delivery of Metronidazole through cellulose acetate membranes, by means of the determination of parameters that quantify the delivery process. Propylene glycol (PG) and tween 20 were selected as delivery enhancers based on their hydrophilic properties, and urea for its lipophilicity, since they increase skin permeability affecting the resistance offered by the stratum corneum. The toxicity of the combination of the active ingredient and the promoters was also evaluated, taking into account that it is a critical aspect of any potential pharmaceutical agent for therapeutic use. Phosphate buffered saline (pH 7.4) was used in the receptor compartment. The physicochemical parameters calculated were the permeation and diffusion coefficients (P and D respectively). To obtain comparative results, all the enhancers were studied at the same concentration (10%). Combinations were previously evaluated at concentrations of 0.5, 5.0 and 10.0% and it was found that the optimal concentration was 10%. The best result was obtained when urea was used as a delivery enhancer. Urea significantly increases the release of MTZ (approximately 16 times more than the control), indicating that it is an effective enhancer of the therapeutic system under study.