[The comparing study between subchronic toxicity and local implantation response of sodium hyaluronan gels for...

According to the requirements of ISO10993-11.2006 and ISO10993-6:r2007 standards, we used SD rats for evaluating the subchronic systemic toxicity and local implantation response of two kinds of sodium hyaluronan gels with different application. The results of 90d subchronic toxicity study by intraperitoneal route showed that the animals of the tested group and control group grew normally. There were no differences in the increases of the body weight, haematological index and clinical biochemistry indexes. The examination of gross pathology and histopathology revealed no abnormal changes caused by the test substance during the process. But there was different degree test article residual in the body of the animals at the end of the experiment. It was observed in the local subcutaneous implantation that at the early stage, gel A had mild inflammatory response, cysts were seen clearly, and new blood capillaries were visible at local area. Later, the wall got thinner and dense with little tissue reaction. Gel B also had mild inflammatory response earlier, but it totally disappeared after 14 days of implantation. It can be concluded that the gel products with different characteristics decided its degradation and metabolic process in the body of the test animals and therefore the areas of application of the products clinically. Meanwhile, we compared the evaluation method of subchronic systemic toxicity and local implantation response in risk assessment, providing reference for the choice of biological safe testing.