COMPARATIVE PHARMACOKINETICS OF LIQUIRITIN AND CYANOCOBALAMIN COMBINATION IN RAT SERUM: AN HPLC-BASED STUDY

Abstract

Liquiritin and cyanocobalamin (vitamin B12) were evaluated individually and in combination in a preclinical antidepressant research program, with fluoxetine included as a reference treatment. Healthy adult male Wistar rats were allocated to four pharmacokinetic groups (n=6): liquiritin 25 mg/kg, cyanocobalamin 100 µg/kg, liquiritin plus cyanocobalamin 25 mg/kg + 100 µg/kg, and fluoxetine 10 mg/kg, administered orally. Blood was collected at scheduled post-dose intervals, serum was separated, proteins were precipitated with methanol, and analytes were quantified using the reported RP-HPLC conditions with a C18 column. The consolidated HPLC dataset showed Cmax values of 21.8100 µg/mL for liquiritin, 23.0696 µg/mL for cyanocobalamin, 16.1558 µg/mL for the combination and 7.7428 µg/mL for fluoxetine. Tmax values were 4, 2, 4 and 4 h, respectively. Reported AUC₀–₂₄ values were 137.16, 109.62, 147.95 and 73.70 µg·h/mL, respectively. The combination therefore showed the highest reported AUC₀–₂₄ but a lower Cmax than liquiritin or cyanocobalamin alone. These findings provide a descriptive comparison of systemic concentration profiles; they do not by themselves establish absolute bioavailability enhancement or a pharmacokinetic interaction mechanism.