Acrylic matrix type nicotine transdermal patches: In vitro evaluations and batch-to-batch uniformity

Nicotine transdermal patches (NTPs) were fabricated using an acrylic pressure sensitive adhesive emulsion to form a transparent matrix film. An automated thin layer chromatography (TLC) plate scraper was Used to control the thickness of the cast nicotine matrix film. The in vitro release behavior and permeation of nicotine across abdominal human epidermis (HE) from the NTPs was Studied using United States Pharmacopeia (USP) dissolution apparatus 5 (paddle over disk) and modified Franz-diffusion cell, respectively. The release of nicotine from the NTPs showed a good linear correlation with the square root of time (R-2 >0.99). This indicated a matrix diffusion controlled-release mechanism. The surface morphology of the matrix of the NTP was uniform and nonporous before and after release, indicating that the dried adhesive nicotine matrix was a homogeneous single-phase film. Neither the nicotine content in the range 4.70-8.41% w/w nor the film thicknesses of the NTPs affected the apparent diffusion coefficient of nicotine in the acrylic matrix. A good relationship between the amount of nicotine permeated across the HE and the square root of time was also observed with R-2 >0.98. This Study also showed that the NTPs provided a good delivery system with more than 65% of the nicotine delivery being controlled by the device. Moreover, the release of nicotine from six production batches met the criteria of USP 24. This finding presented a good potential of this method for upscaling to industrial manufacturing.