title: HPLC assays to simultaneously determine the angiotensin-AT1 antagonist losartan as well as its main and active metabolite EXP 3174 in biological material of humans and rats.
abstract: Novel rapid and sensitive HPLC assays were developed to simultaneously determine losartan and its main active metabolite EXP 3174 in biological material of humans and rats following solid-phase or liquid-liquid extraction. The analytes were separated on a 3 microm particle-sized ULTREMEX CN column, which was preceded by a 5 microm particle-sized guard column, using UV-detection at 245 nm. The assays provided high sensitivity with limits of quantification (LoQ) of 5 ng ml(-1) for both compounds in human and rat plasma and 10 ng ml(-1) in human and rat urine, respectively. In rat blood, bile and various tissues, limits of quantifications were achieved that ranged 10-15 ng per ml and per 100 mg tissue, respectively, for both analytes.
authors.affiliation: Department of Pharmacology, J.W. Goethe-University, Biocenter Niederursel, Frankfurt/Main, Germany. asoldner@box-a.nih.gov
authors.forename: A
authors.initials: A
authors.lastname: Soldner
authors.forename: H
authors.initials: H
authors.lastname: Spahn-Langguth
authors.forename: E
authors.initials: E
authors.lastname: Mutschler
mesh_terms: D000803:Angiotensin I / Q000378:metabolism*; D057911:Angiotensin Receptor Antagonists; D000818:Animals; D000959:Antihypertensive Agents / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D007093:Imidazoles / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D019808:Losartan / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D051381:Rats; D011945:Receptors, Angiotensin / Q000378:metabolism; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D013777:Tetrazoles / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D014018:Tissue Distribution
chemical_list: D057911:Angiotensin Receptor Antagonists; D000959:Antihypertensive Agents; D007093:Imidazoles; D011945:Receptors, Angiotensin; D013777:Tetrazoles; D000803:Angiotensin I; C066026:losartan carboxylic acid; D019808:Losartan