title: Sensitive liquid chromatography assay with ultraviolet detection for a new phosphodiesterase V inhibitor, DA-8159, in human plasma and urine.
abstract: A sensitive high-performance liquid chromatographic (HPLC) method with ultraviolet absorption detection (292 nm) was developed and validated for the determination of the new phosphodiesterase V inhibitor, DA-8159 (DA), in human plasma and urine. A single step liquid-liquid extraction procedure using ethyl ether was performed to recover DA and the internal standard (sildenafil citrate) from 1.0 ml of biological matrices combined with 200 microl of 0.1M sodium carbonate buffer. A Capcell Pak C18 UG120 column (150 mm x 4.6 mm I.D., 5 microm) was used as a stationary phase and the mobile phase consisted of 30% acetonitrile and 70% 20mM potassium phosphate buffer (pH 4.5) at a flow rate of 1.0 ml/min. The lower limit for quantification was 5 ng/ml for plasma and 10 ng/ml for urine samples. Within- and between-run accuracy and precision were < or =15 and < or =10%, respectively, in both plasma and urine samples. The recovery of DA from human plasma and urine was greater than 70%. Separate stability studies showed that DA is stable under the conditions of analysis. This validated assay was used for the pharmacokinetic analysis of DA during a phase I, rising dose study.
authors.affiliation: Department of Pharmacology, College of Medicine, Seoul National University, 28 Yongun-dong, Chongro-gu, Seoul 110-799, South Korea.
authors.forename: Joo Youn
authors.initials: JY
authors.lastname: Cho
authors.forename: Hyeong Seok
authors.initials: HS
authors.lastname: Lim
authors.forename: Kyung Sang
authors.initials: KS
authors.lastname: Yu
authors.forename: Hyun Joo
authors.initials: HJ
authors.lastname: Shim
authors.forename: In Jin
authors.initials: IJ
authors.lastname: Jang
authors.forename: Sang Goo
authors.initials: SG
authors.lastname: Shin
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases; D002851:Chromatography, High Pressure Liquid; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D006801:Humans; D010726:Phosphodiesterase Inhibitors / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D010727:Phosphoric Diester Hydrolases / Q000187:drug effects*; D011743:Pyrimidines / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D013449:Sulfonamides; D000096926:Benzenesulfonamides
chemical_list: D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054706:Cyclic Nucleotide Phosphodiesterases, Type 5; D010726:Phosphodiesterase Inhibitors; D010727:Phosphoric Diester Hydrolases; D011743:Pyrimidines; D013449:Sulfonamides; C517381:PDE5A protein, human; C419664:udenafil; D000096926:Benzenesulfonamides