title: Determination of metabolic profile of anti-malarial trioxane CDRI 99/411 in rat liver microsomes using HPLC.
abstract: CDRI 99/411 is a potent 1,2,4-trioxane anti-malarial candidate compound of the Central Drug Research Institute, India. This study aimed to conduct comprehensive in vitro metabolic investigations of CDRI 99/411 to corroborate its preclinical investigations. Preliminary in vitro metabolic investigations were performed to assess the metabolic stability [in vitro half-life (t(1/2) ) and in vitro hepatic intrinsic clearance (Cl(int) )] of CDRI 99/411 in male Sprague-Dawley rat and human liver microsomes using validated high-performance liquid chromatography with photodiode array detector. The observed in vitro t(1/2) of the compound in rat and human liver microsomes was 13 min with in vitro Cl(int) 130.7±25.0 μL/min/mg and 19 min with in vitro Cl(int) 89.3 ± 17.40 μL/min/mg. These observations suggested moderate metabolic degradation and in vitro Cl(int) with insignificant difference (p>0.05) in the metabolic stability profile in rat and human. Hence, in vitro metabolic investigations were performed with rat liver microsomes. It was observed that CDRI 99/411 exhibited sigmoidal kinetics. At nonlinear regression (r ≥ 0.99) EC(50) and Hill slope values were 17 µm and 1.50, respectively. The metabolism of CDRI 99/411 was primarily mediated by CYP3A2 and was inferred by CYP reaction phenotyping with known potent inhibitors. Two metabolites of CDRI 99/411 were detected which were undetectable on incubation with 1-aminobenzotriazole and ketoconazole.
authors.affiliation: Pharmacokinetics and Metabolism Division, Central Drug Research Institute (Council of Scientific and Industrial Research, India), Lucknow, Uttar Pradesh, India.
authors.forename: Smriti
authors.initials: S
authors.lastname: Mishra
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Manickavasagam
authors.forename: Girish Kumar
authors.initials: GK
authors.lastname: Jain
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000032:analysis / Q000378:metabolism* / Q000493:pharmacokinetics; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism; D065692:Cytochrome P-450 CYP3A Inhibitors; D006571:Heterocyclic Compounds / Q000032:analysis / Q000378:metabolism* / Q000493:pharmacokinetics; D006801:Humans; D007654:Ketoconazole / Q000494:pharmacology; D007700:Kinetics; D008297:Male; D055442:Metabolome; D008862:Microsomes, Liver / Q000378:metabolism*; D017711:Nonlinear Dynamics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013141:Spiro Compounds / Q000032:analysis / Q000378:metabolism* / Q000493:pharmacokinetics; D014230:Triazoles / Q000494:pharmacology
chemical_list: C529215:99-411 compound; D000962:Antimalarials; D065692:Cytochrome P-450 CYP3A Inhibitors; D006571:Heterocyclic Compounds; D013141:Spiro Compounds; D014230:Triazoles; C033020:1-aminobenzotriazole; D051544:Cytochrome P-450 CYP3A; D007654:Ketoconazole