Distribution of Tramadol Hydrochloride in Rats

Objective To investigate the in vivo distribution of tramadol hydrochloride in rats. Methods After an oral administration of tramadol hydrochloride (684 or 1368 mg/kg), concentrations of tramadol hydrochloride in the heart, lung, liver, kidney, spleen, brain and blood were determined by a TLC scanning chromatography. Results The levels of tramadol hydrochloride in the kidney , lung , blood , liver , brain , spleen and heart were 112±15, 59±17, 53±31, 32±19.7, 22±11.5, 20±20, 16.7±8.3 μg/g (μg/ml) in the rats given three times LD 50 dose ( 684 mg/kg) respectively, and the concentrations of tramadol hydrochloride in the blood, lung , liver, heart, kidney, brain and spleen in rats given six times LD 50 dose (1368 mg/kg) was 107.6±7.2, 26.3±20, 11.7±6.6, 11.2±7.2, 10.3±3.6, 6.38±0.2, 6.1±0.3 μg/g (μg/ml) respectively . Conclusion In rats with three times LD 50 dose, the levels of tramadol hydrochloride in kidney, lung, blood are higher, whereas in the rats with six times LD 50 dose, the higher concentrations of tramadol hydrochloride are determined in the blood, lung and liver, suggesting that blood, liver, lung, kidney and spleen are suitable samples for forensic toxicological analysis in tramadol hydrochloride poisoning cases.