title: LC-MS/MS method for the determination of pitolisant: application to rat pharmacokinetic and brain penetration studies.
abstract: A simple and sensitive LC-MS/MS method was developed and validated for the quantitation of pitolisant, an H3 receptor antagonist/inverse agonist. Acetonitrile protein precipitation technique was used to prepare rat blood and brain tissue homogenate samples by using aripiprazole as internal standard (IS). Chromatographic separation was performed by using Xbridge column (2.1 × 50 mm, 3.5 µm) with a gradient elution program. The mobile phase consists of ammonium formate (10 mm) with 0.2% formic acid and acetonitrile. Multiple reaction monitoring mode was used in positive polarity with a transition of m/z 296.3 → 98.2 for the pitolisant and m/z 448.2 → 285.3 for the IS. The calibration curves were linear in the range of 0.1-100 ng/mL in both the blood and brain homogenate samples. This method was applied to quantify samples obtained from the pharmacokinetic and brain penetration studies in male wistar rats. Mean maximum concentration, area under the curve from zero to infinity and half-life of the pitolisant were found to be 3.4 ± 1.7 ng/mL, 5 ± 4 ng h/mL and 1.9 ± 0.3 h, respectively, after a 3 mg/kg oral dose. The mean calculated concentrations in the brain were found to be 38, 60 and 52 ng/g at 0.5, 1 and 2 h, respectively.
authors.affiliation: Biopharmaceutical Research, Suven Life Sciences Ltd, Serene Chambers, Road 5, Avenue 7, Banjara Hills, Hyderabad, 500034, India.
authors.forename: Ramakrishna
authors.initials: R
authors.lastname: Nirogi
authors.forename: Devender Reddy
authors.initials: DR
authors.lastname: Ajjala
authors.forename: Vishwottam
authors.initials: V
authors.lastname: Kandikere
authors.forename: Hanumanth Rao
authors.initials: HR
authors.lastname: Pantangi
authors.forename: Mahesh Reddy
authors.initials: MR
authors.lastname: Jonnala
authors.forename: Gopinadh
authors.initials: G
authors.lastname: Bhyrapuneni
authors.forename: Nageswar Rao
authors.initials: NR
authors.lastname: Muddana
authors.forename: Himabindu
authors.initials: H
authors.lastname: Vurimindi
mesh_terms: D000818:Animals; D019540:Area Under Curve; D001921:Brain / Q000378:metabolism*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006633:Histamine Antagonists / Q000097:blood / Q000493:pharmacokinetics*; D057230:Limit of Detection; D008297:Male; D010880:Piperidines / Q000097:blood / Q000493:pharmacokinetics*; D051381:Rats; D017208:Rats, Wistar; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D006633:Histamine Antagonists; D010880:Piperidines; C516975:pitolisant
keywords: H3 receptor; LC-MS/MS; Parkinson's disease; narcolepsy; pitolisant; schizophrenia