Effect of Adhesives on the Properties of Adhesion, Drug Release and Skin Permeation of Lidocaine Tapes

A generic drug is defined as a drug product that is comparable to a brand name drug in terms of dosage, form, strength, route of administration, quality, performance characteristics, and indicated use. Generic drugs for topical use, in the case of sheet-like products, are required to be the same as the original drug in terms of application area and dosage form. The composition of such generic drug formulations may differ from that of the original product. The adhesive of any pharmaceutically-active tape that directly contacts the skin plays a role in delivering the active ingredient into the skin, and affects the sensation and ease of handling. Therefore, adhesives are an important ingredient in these products. Thus, the aim of this study was to characterize original and generic lidocaine tape products, and to evaluate the adhesive properties of each. The tack force, peel strength and shear adhesion were measured as adhesive properties. In addition, in vitro drug releasing profiles and skin permeation profiles of the products were evaluated. In vivo transdermal absorption was also evaluated to predict the possibility of adverse effects. Adhesive properties differed among the three analyzed products. These differences may have been caused by differences in the adhesives. Drug-releasing profiles and skin permeation profiles also differed among the three products, even though the pharmacokinetics were not significantly different. By obtaining an adequate understanding of the characteristics of original and generic products, we will be able to provide better tailor-made medications for drug therapies for patients.