FORMULATION AND EVALUATION OF TETRACAINE HYDROCHLORIDE POLYMERIC FILMS FOR TOPICAL APPLICATION
Bulletin of Pharmaceutical Sciences
Eudragit polymeric films were investigated as a potential drug delivery system for controlling the release of tetracaine HCl. The effect of modification in polymeric ratio of both Eudragit RS100 and RL100, drug loading and nature of plasticizer on the in vitro release of the drug from each film into a receiving medium of citrate buffer (pH=5) was measured. The obtained results indicated that the film containing Eudragit polymer and plasticizer affected the drug release rate and that the release
... nd that the release followed Higuchi-diffusion model. The release rate was found to be enhanced with increasing Eudragit RL100 ratio. The release rate was also found to be directly proportional to drug concentration. Tetracaine HCl was slowly released from Eudragit RS100 / dimethylphthalate films and Eudragit RS100 / diethyl-phthalate films. Eduragit films plasticized with GTA, PEG400 and PG produced a fast drug release. This study demonstrated that tetracaine HCl was compatible with Eudragit RS100 as indicated by the clear and transparent formed films. Also, the characterizations of Eudragit films were conducted by IR-spectroscopy, X-ray diffraction pattern and differential thermal analysis to explore the possibility of the drug polymer interaction occurring between tetracaine HCl and either Eudragit RS100 or Eudragit RL100. The therapeutic potential of tetracaine HCl Eudragit polymeric films was evaluated using "Tail-Flick" method on a Techano analyiseometer model. Results indicated that tetracaine HCL polymeric film composed of Eudragit RS100: Eudragit RL100 ratio (8:2) and plasticized with 20% w/w diethylphthalate gave a long duration of analgesic response.