Absolute bioavailability studies of a new oral topotecan formulation in Chinese patients using UHPLC-MS/MS.
Xinze(®) is a new capsule formulation of topotecan being made in China which is similar to Hycamtin(®), the currently available oral formulation approved in 2007 for the treatment of relapsed small cell lung cancer (SCLC). As topotecan bioavailability and pharmacokinetic data for Chinese patients is limited, the aim of the study was to assess the absolute bioavailability and pharmacokinetics of Xinze(®) in Chinese patients with SCLC treated intravenously (i.v.) with 1.5mg/m(2)/d topotecan (Hycamtin(®)) on day 1 and treated orally with 1.5mg/m(2)/d topotecan on day 2. An ultra high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for the determination of total topotecan (lactone and carboxylate forms) and of topotecan in the lactone form in human plasma samples. The method was validated with respect to selectivity, extraction recovery, matrix effect, linearity, intra- and inter-day precision, accuracy, and stability. The quantification limits were 0.5ng/mL for total topotecan and 0.1ng/mL for topotecan in the lactone form. The mean absolute bioavailability of total topotecan and topotecan in the lactone form was 42.24±12.9% and 47.18±16.9%, respectively, values which illustrate good systemic exposure. The presented results demonstrated this method can be a sensitive and efficient tool for bioavailability studies of topotecan.
Beijing Key Laboratory of Clinical Study on Antitumor Molecular Target Drugs, Department of Medical Oncology, Cancer Institute/Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China.
Ning
N
Li
Xiaohong
X
Han
Jianliang
J
Yang
Lin
L
Gui
Yuanyuan
Y
Song
Ping
P
Du
Yuankai
Y
Shi
D000284:Administration, Oral; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use; D001682:Biological Availability; D002681:China; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D007262:Infusions, Intravenous; D057230:Limit of Detection; D008175:Lung Neoplasms / Q000188:drug therapy / Q000473:pathology; D008297:Male; D015203:Reproducibility of Results; D055752:Small Cell Lung Carcinoma / Q000188:drug therapy / Q000473:pathology; D053719:Tandem Mass Spectrometry / Q000379:methods*; D059004:Topoisomerase I Inhibitors / Q000008:administration & dosage / Q000493:pharmacokinetics / Q000627:therapeutic use; D019772:Topotecan / Q000008:administration & dosage / Q000493:pharmacokinetics* / Q000627:therapeutic use
D000970:Antineoplastic Agents; D059004:Topoisomerase I Inhibitors; D019772:Topotecan