title: Quantification of zolpidem in human plasma by high-performance liquid chromatography with fluorescence detection.
abstract: A simple, reliable HPLC method with fluorescence detection (excitation 320 and emission 388 nm) was developed and validated for quantitation of zolpidem in human plasma. Following a single-step liquid-liquid extraction, the analyte and internal standard (quinine) were separated using an isocratic mobile phase on a reversed-phase C(18) column. The lower limit of quantitation was 1.8 ng/mL, with a relative standard deviation of less than 5%. A linear dynamic range of 1.8-288 ng/mL was established. This HPLC method was validated with between-batch and within-batch precision of 1.7-4.8 and 1.2-2.3%, respectively. The between-batch and within-batch accuracy was 95.3-100.4 and 95.5-102.7%, respectively. Frequently coadministered drugs did not interfere with the described methodology. Stability of zolpidem in plasma was excellent, with no evidence of degradation during sample processing (autosampler) and 30 days storage in a freezer. This validated method is simple and repeatable enough to be used in pharmacokinetic studies.
authors.affiliation: Biopharmaceutical Research, Suven Life Sciences Ltd, Serene Chambers, Road 7, Banjara Hills, Hyderabad 500034, India. ramakrishna_nirogi@yahoo.co.in
authors.forename: Ramakrishna V S
authors.initials: RV
authors.lastname: Nirogi
authors.forename: Vishwottam N
authors.initials: VN
authors.lastname: Kandikere
authors.forename: Wishu
authors.initials: W
authors.lastname: Shrivasthava
authors.forename: Koteshwara
authors.initials: K
authors.lastname: Mudigonda
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005453:Fluorescence; D006801:Humans; D015394:Molecular Structure; D011725:Pyridines / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D011803:Quinine / Q000032:analysis / Q000592:standards; D012015:Reference Standards; D015203:Reproducibility of Results; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D000077334:Zolpidem
chemical_list: D011725:Pyridines; D000077334:Zolpidem; D011803:Quinine