Preparation of Gelatin Blended Films for Drug Delivery

Abstract

This study aimed to prepare and evaluate the matrix type anesthetic films for using as oral transmucosal (OTD) or transdermal drug delivery systems (TDDS). Gelatin was chosen as the main polymer. Pregelatinized tapioca starch (alpha starch) or gelatinized sago starch was used as a blended polymer. Glycerin (GLY), propylene glycol (PG), polyethylene glycol 400 (PEG400), or deproteinized natural rubber latex (DNRL) was selected as a plasticizer. Either lidocaine base (LB) or its hydrochloride salt (LH) was used as a model drug. The films were obtained by mixing and casting methods before being dried in hot air oven. The amounts of starch and plasticizer affected the water uptake, erosion, and elasticity of films. The films were characterized for their compatibility by using texture analyzer, scanning electron microscopy (SEM), atomic force microscopy (AFM), fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), and X-ray diffractometry (XRD). Gelatin blended with 5 part per hundred of gelatin (phg) alpha starch and 25 phg GLY (Gagly) presented as the appropriate film for OTD. In addition, gelatin blended with 5 phg gelatinized sago starch and 50 phg DNRL (GSNR) gave the suitable patch for TDDS. LB or LH was incorporated into both Gagly film and GSNR patch. The modified Franz diffusion cells were applied for in vitro drug release and permeation studies. Chick chorioallantoic membrane (CAM) and newborn pig skin were used to evaluate the permeation of lidocaine as buccal and skin models, respectively. Both LB and LH could release from Gagly films and GSNR patches. The release of LH was higher than LB in both Gagly films and GSNR patches. Moreover, the drugs could permeate through both CAM and newborn pig skin. For Gagly films, LH could permeate through CAM higher than LB. For GSNR patches, LH could permeate through newborn pig skin lower than LB. This indicated that the lidocaine release or permeation from these films depended on drug property. Medicated Gagly films and GSNR patches exhibited different kinetics of drug release and permeation. Most drug release kinetics of Gagly films in short time and 8 h drug release were fitted to zero order kinetic and first order kinetics, respectively. Most drug permeation kinetics were fitted to first order kinetics. For GSNR patches, most drug release kinetics were fitted to first order or Higuchi's kinetic model. The permeation kinetics of LB- GSNR patches were zero order kinetics or first order kinetics, while that of LH-GSNR patches was not statistically different for three types of kinetics. The results from the stability test for 3 months indicated that these films or patches were recommended to be stored at low temperature. Moreover, the low irritation with CAM test of medicated Gagly films signified their safety for buccal delivery. In conclusion, gelatin and starch could be blended with plasticizer and anesthetic drug such as LB and LH to obtain the suitable film for use as oral transmucosal films or transdermal patches.