DESIGN AND IN-VIVO EVALUATION OF TOPICALLY APPLIED CHLORPHENIRAMINE MALEATE GELS

This study was aimed at formulating topically applied Chlorpheniramine maleate gel (CPM gel). Combined effects of propylene glycol and polyethylene glycol as permeation enhancers were investigated using response surface methodology. The formulated gels were characterized for various formulation attributes including viscosity, homogeneity, pH, spreadability and accelerated stability studies (40 ± 0.5 °C / 75% RH). In-vitro studies were also conducted using silicone sheets and rat skin as model membranes. The permeation study revealed that an increase in the drug permeation across model membranes was due to an increasing concentration of enhancers. Based on formulation attributes and permeation parameters, FM6 was identified as optimized formulation. The drug release from optimized formulation followed the first order release kinetics. Draize’s skin irritation test was conducted on healthy human volunteers to elucidate the safety profile of the formulations. Pharmacokinetic profiling of optimized gel was also conducted, and finally, the optimized gel was subjected to anti-allergenic challenge. Pharmacokinetic studies revealed that topical application produced comparable results with the oral delivery and the optimized gel was excellent in the management of allergy in rabbits. This study showed that the optimized CPM gel (FM6) containing a combination of propylene glycol and polyethylene glycol as permeation enhancers would be beneficial for addressing topical allergies and should be further tested in more clinically relevant settings.