Characterization, in vitro release and permeation studies of nicotine transdermal patches prepared from deproteinized natural rubber latex blends

The nicotine transdermal patches (NTPs) are available used for smoking cessation; however, they still should be developed for high efficacy and low cost. In this study, deproteinized natural rubber latex (DNRL) blended with hydroxypropylmethyl cellulose (HPMC) and dibutylphthalate (DBP) were used as matrix membrane for nicotine (NCT) delivery. Several techniques, i.e., FT-IR, XRD, DSC, and SEM were used to characterize the compatibility of each ingredient in the blended patches. A backing layer was used to protect NCT from volatilization. Five different types of backing layer were evaluated for their effects on in vitro release and skin permeation of NCT from the formulated matrix membranes. The backing layer with highest moisture vapor transmission rate (MVTR) and lowest oxygen transmission (OT) supposed to give higher NCT release and skin permeation due to increasing of skin hydration and its occlusive effect. The kinetic of in vitro release and permeation was demonstrated the monophasic slow release pattern which confirmed by first order and zero order kinetics, respectively. Therefore, the backing layer could be appropriated and used conveniently in the preparation of NTPs.     

Deproteinised natural rubber used as a controlling layer membrane in reservoir-type nicotine transdermal patches

Reservoir-type nicotine transdermal patches (NTPs), composed of a concentrated nicotine solution embedded between a backing layer and a controlling layer membrane, were constructed by a heat-sealing technique. The aim of this research was the preparation of a novel controlling layer membrane from deproteinised natural rubber latex (DNRL). The ultimate tensile strength and percentage of elongation at breakage of the DNRL membrane were 0.23 ± 0.04 MPa and 604.46 ± 95.38%, respectively. The DNRL membrane existed as an amorphous phase and was poorly hygroscopic and dense. FT-IR and DSC analysis demonstrated that the membrane consisted almost entirely of isoprene functional groups with a T_g of −64.79 °C. The effects of the DNRL membrane thickness (100–300 μm) and different nicotine concentrations in the reservoir (1.75–4.25 mg/cm²) on the nicotine release rate and nicotine permeation through a pig skin membrane were studied in vitro. The in vitro nicotine release rate and skin permeation rate increased with decreasing membrane thickness and increasing nicotine content in the reservoir. The release and permeation profiles followed first- and zero-order kinetics, respectively. The release and permeation performance was similar to a commercially available Nicotinell TTS-20 patch. The newly developed NTPs were stable under storage in a tightly sealed container at 4 °C or at ambient temperature for up to 3 months. Thus, DNRL is suitable for use as a controlling layer membrane in NTPs in transdermal drug delivery systems.