Abstract: Objective To assess the safety of Haoqin nasal drops and provide a reference for safe clinical medications for allergic rhinitis (AR). Methods In single-dose toxicity test, SD rats were administered with the maximum tolerated dose (0.4 mL·kg^-1) of Haoqin nasal drops, which was equivalent to 1440 mg crude drug/kg. The overall state, body weight, food intake, toxic symptoms, and mortality of these rats were observed over a period of 14 days, followed by histopathological examination of major tissues and organs. In the repeated dose toxicity test, SD rats were divided into high-dose(270.0 mg·kg^-1), medium-dose (135.0 mg·kg^-1), low-dose(67.5 mg·kg^-1) groups and a control group, with 30 rats in each. The rats were administered with this drug for 13 weeks, followed by 4 weeks of recovery. The overall state of these rats was observed daily while their body weight was measured weekly. Such indexes were recorded as parameters of hematology, coagulation and blood biochemistry, urine indexes, organ coefficients and results of histopathological examination. Results In the single-dose toxicity test, the overall state, body weight, food intake and other indicators of rats were normal. In the repeated-dose toxicity test, some of the indicators of the medication group, such as red blood cell count and the average hemoglobin concentration of red blood cells, reticulocytes, hemoglobin, hematocrit and urea at the end of the dosing period, were statistically different from those of the control group, but within the normal range of fluctuation. In the high-dose group, there was one case of male hepatocyte vacuolation and one case of a slight decrease in female bone marrow hematopoietic stem cells. The two cases were considered a spontaneous disease in rats based on blood biochemical indicators. Conclusion The MTD of Haoqin nasal drops is 1440 mg crude drug/kg (equivalent to 400 times the intended clinical dose) for a single administration, and the NOAEL for the 13-week repeated doses is 270 mg crude drug/kg (equivalent to 75 times the intended clinical dose). Haoqin nasal drops show no significant toxicity and prove quite safe at therapeutic dosages.

Key words: Haoqin Nasal Drops, Single Administration, Repeated Administration, MTD, NOAEL, Safety Assessment, Rats