Formulation Research Of Tetracaine Gel

Tetracaine is a Na+blockers, potent local anesthetic, mainly used local anesthesia and spinal anesthesia. At present, the clinical use of the drug dosage forms are injections and gels. Pain is a chronic and widespread medical problems, hospital and community are widespread, pain relief is an important therapeutic goal. Survey shows that pain limits the patient’s functional status, affects their quality of life, and weaks their ability to work. The main advantage lies in its topical anesthesia application process is painless, as local anesthesia infiltration doesn’t destroy tissue. Painless treatment, especially minor surgery as provided venipuncture pain treatment for pediatric patients is critical. In a busy emergency room, the main disadvantage of using topical anesthesia is anesthesia onset time.Tetracaine clinical use is limited by its high penetration delay time (35 to 40min). Because it is usually set before venipuncture or intravenous tube used, so the delay time can be reduced to improve the effectiveness of the drug to patients. And in the formulation, tetracaine is unstable, storage inconvenient. It is also an important reason for limiting its use. This paper is mainly based on these two points, to improve formulations of tetracaine.The purpose of this article is by optimizing the penetration enhancers and drug matrix, to develop a tetracaine prescription with quick onset of action and convenient storage. Choose to use the skin of nude mice when measuring vitro percutaneous kinetic parameters of tetracaine. Ks/v of tetracaine is 5.19, and this suggests that liposoluble of tetracaine is too large, the stratum corneum and stratum corneum to allocation of active transdermal skin significantly affect the behavior of tetracaine. In this study, by using the addition of chemical penetration enhancers, and we hope to improve tetracaine percutaneous penetration. In order to study the influence of a variety of chemical penetration enhancers on transdermal behavior of tetracaine, we selected vitro experiments to optimum penetration enhancers. In this paper,through investigating stability and transdermal permeation behavior study of tetracaine. we uses different drug technology to get a suitable drug technology.The results show that selection of 2% xanthan gum is an aqueous gel matrix, with advantages of good formability, good spreadability and moderate viscosity. When ethanol is added to the formulation as penetration enhancers, the cumulative amount of permeation of tetracaine can increase to 1.35 times, and its delay time is substantially no influence, but there are still problems of drug instability, and will generate new impurities. By high resolution liquid chromatography-mass spectrometry to identify new impurities structure, the structure is 4-(n-butylamino)benzoic acid ethyl ester. When using microemulsion gel as a substrate, at a high temperature test, the amount of of related substances of tetracaine significantly reduced, the amount of 4-(n-butylamino)benzoic acid is 1/7 of control group.