Aqueous dispersions of water-soluble and water-insoluble cellulosic polymers as vehicles for topical drug delivery
Abstract
Topical application of therapeutic agents is an important route of drug administration for both local and systemic treatment of diseases. In this study aqueous dispersions of water-soluble and water-insoluble cellulosic polymers, which form films on drying, have been developed to deliver therapeutic agents to the skin. Flexible and transparent films of ethylcellulose and either methylcellulose, hydroxypropylmethylcellulose, or hydroxypropylcellulose could be cast from the aqueous dispersions. The ability of the mixed cellulosic polymer films to deliver selected therapeutic agents has been studied. The release of active ingredients from free films cast from the aqueous dispersions was evaluated using Franz diffusion cells and the finite dose technique. Release of drug from free films was studied as a function of the type and concentration of water-soluble polymer used and the water-soluble character of the active ingredient. Physical characterization of the film systems was performed and examined in relation to release of the active ingredient. Animal models specific for the active agent employed were used to evaluate the delivery of the therapeutic agents from the film systems following topical application in vitro and in vivo. The rate and extent of drug release from mixed cellulosic films were shown to be dependent on the amount and/or type of water-soluble polymer component of the films and the water solubility of the active ingredient. The physical characteristics of the films were also affected by the type and concentration of the water-soluble polymer employed. The penetration of p-aminobenzoic acid through hairless mouse skin from free film application was dependent on the type of water-soluble polymer contained in the film. Topical efficacy for a common antifungal agent from a mixed cellulosic polymer delivery system vs. a commercially available product was demonstrated using a guinea pig model.
Degree
Ph.D.
Advisors
Peck, Purdue University.
Subject Area
Pharmaceuticals
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