Preparation, in vitro characterization and pharmacokinetics of paclitaxel thermosensitive gel / 药学学报

Local drug delivery is a new strategy to prevent postoperative recurrence of cancer, thermosensitive gel is a typical topical drug delivery system. In this study, a novel paclitaxel thermosensitive gel (PTG) was prepared to prevent recurrence after chemotherapy for cancer, the effects of drug particle size on release and absorption rate in vivo were investigated. Paclitaxel suspensions with different particle sizes were prepared by medium grinding, high pressure homogenization, air crushing and screening. Using poloxamer as the gel matrix and carbomer as the biological adhesive, Box-Behnen was used to optimize the formulation of PTG. The morphology, viscosity, rheological properties and biological adhesion of thermosensitive gel were characterized. The relationship between dissolution and release of thermosensitive gel was investigated by weight loss method, pharmacokinetics was studied in rats. The paclitaxel suspensions with the particle sizes of 350 nm, 800 nm, 3 μm and 9 μm were prepared, 19% poloxamer 407, 4% poloxamer 188 and 0.1% carbomer were used to prepare PTG. The phase transition temperature of thermosensitive gel was 30 to 35 ℃, there was a good linear relationship between in vitro release and gel dissolution. In the pharmacokinetic study, area under the curve (AUC0-t) increased with the decrease of particle size. In general, the PTG prepared in this study can rapidly change into gel under human body temperature, provided with good adhesion. The release rate in vitro is closely related to the particle size, the release rate increased with the decrease of particle size. This study provides data support for preventing postoperative recurrence of cancer. The animal welfare and experimental process in this paper follow the regulations of the Animal Ethics Committee of the Academy of Military Medical Sciences.

Based on clinical application research progress of thermosensitive gel in different drug delivery sites / 药学学报

The advantages of local administration are as follow: release drugs directly at the lesion, increase the drug concentration in lesion location and reduce the side effects of systemic administration. Thermosensitive gel is one of typical local administration agents. It exhibits the different physical characteristics with the change of temperature. It is sol-gel at low temperature or storage temperature, while when the temperature rises to the transition temperature or near the body temperature, it is semisolid gel with a certain viscoelasticity, and can recover rapidly. It can enhance the local adhesion, which prolongs the local retention time of drugs. As a result, thermosensitive gel can control and display the release of drugs, which can significantly improve the bioavailability of drugs. This review summarizes the characteristics of thermosensitive gel, thermosensitive materials, and its application in different parts: nasal cavity, eye, vagina, periodontal, skin, tumor and joint cavity, based on clinical needs.