Effect of Drying Conditions and Permeation Enhancers on Film Forming Properties of Natural Rubber Latex Blended Films

Abstract

Introduction: Transdermal drug delivery provides several advantages including avoidance of first-pass metabolism, possibly to attain sustained and constant drug level, provide good patient compliance, and ease of usage and withdrawal. However, the skin serves an excellent barrier that a drug which can be penetrated to stratum corneum must have small molecules and lipophilic properties. Several enhancers are also able to enhance drug delivery via the skin. The deproteinized natural rubber latex (DNRL) transdermal patch containing various enhancers had never been studied in film forming characteristic. Thereby, this work was aimed to study on the film forming of latex film containing various enhancers under different casting temperatures and fan speeds of oven. Materials and methods: The blended DNRL films were prepared by mixing 100 phr DNRL with 10 phr hydroxypropylmethylcellulose (HPMC) as a polymer blend, 10 phr dibutyl phthalate (DBP) as a plasticizer, and various enhancers, i.e., oleic acid, isopropyl palmitate (IPP), propylene glycol (PG), olive oil, and menthol in the concentration of 5, 10 15 and 20 phr, and prepared under different casting temperatures at 45°c and 70°C, and fan speeds of oven at 0%, 25% and 100% of the maximum speed. Physical appearance was investigated and photographed. Results and discussion: The blended films containing various enhancers were constructed using different drying time depended on types and concentrations of enhancer. Increasing the concentration of oleic acid and menthol used longer drying time. While increasing the concentration of IPP, PG and olive oil provided different results. Drying time of films containing IPP, PG and olive oil increased when increasing concentration until optimum level. After that, it decreased due to the incompatibility at too high concentrations of these enhancers. Moreover, casting temperatures and fan speeds of film forming affected the drying time of film. As expected, casting temperatures and fan speeds of film forming increased, drying times were decreased. Conclusions: The drying time in film forming and film appearance obtained from each formula depended on types and concentrations of enhancer, as well as, casting temperatures and fan speeds.