Objective: The aim of this study was to determine the acute toxicity and anti-inflammatory activity of new 1,3,4-thiadiazole derivatives to assess their potential as pharmacological agents. Methods: Acute toxicity was evaluated in outbred white male mice using the fixed-dose procedure according to OECD Guideline No. 420. The substances were administered orally at a dose of 2000 mg/kg. The anti-inflammatory potential was assessed using a carrageenan-induced paw edema model in rats. The animals were treated with the test substances at doses of 50 mg/kg and 100 mg/kg prior to carrageenan injection. Results: In the acute toxicity test, no mortality or significant changes in body weight were observed. The average lethal dose (LD50) was determined to be greater than 2000 mg/kg, classifying the substances as Class V (practically non-toxic) according to the OECD classification. In the anti-inflammatory assay, the derivatives demonstrated significant activity. Specifically, substances administered at a dose of 50 mg/kg showed the most pronounced inhibition of paw edema compared to the control group. Conclusion: The studied 1,3,4-thiadiazole derivatives exhibit a high safety profile with low toxicity and possess significant anti-inflammatory properties, particularly at lower doses, suggesting their potential for further pharmaceutical development.

1,3,4-thiadiazole derivatives, acute toxicity, anti-inflammatory activity, carrageenan-induced edema, LD50, OECD guidelines.

OECD (2001) Guideline for testing of chemicals. Acute Oral Toxicity – Fixed Dose Procedure No 420.

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