An investigation into the transdermal delivery of nifedipine

A systematic attempt to develop a transdermal delivery system for nifedipine is presented. Measured physicochemical properties influencing percutaneous absorption such as solubility and partition coefficient confirmed the drug's potention for such a formulation approach. However, studies involving permeation through hairless mouse skin from a range of hydrophilic and hydrophobic donor vehicles indicated inadequate penetration. Attempts to increase the drug flux through the animal skin or a range of artificial membranes alone or in parallel by use of the penetration enhancers sodium lauryl sulphate 1% and propylene glycol 20% in a sodium carboxymethylcellulose 3% gel base failed to raise the drug flux to an acceptable level. Likewise increase in the drug thermodynamic gradient across the skin by use of mixed solvents or supersaturated drug solutions was ineffective if an aqueous receiving phase was used. Collectively the results suggest that the development of a transdermal delivery system for the chemically unmodified drug in humans is unlikely to be successful.