A validated LC-MS/MS method for analysis of Cabergoline in human plasma with its implementation in a bioequivalent study: investigation of method greenness.

Cabergoline (CAB) is effective prolactin lowering drug. Evaluation of the bioequivalence for the new test product (0.5 mg CAB film-coated tablets) in Egypt is strongly needed for approval of the drug by the official health authority. Therefore, a highly sensitive and rapid (LC-MS/MS) method was validated for CAB analysis in human plasma. CAB was extracted from plasma via diethyl ether using Quetiapine (QUE) as an internal standard. Multiple reaction monitoring (MRM) in positive ion mode was used, m/z 452.3 → 381.2 for CAB and 384.2 → 253.1 for QUE. Separation was accomplished on a reversed-phase C18. FDA procedures for the bio-analytical method were followed. The method was used in the bioequivalence study to compare the test product (0.5 mg CAB) versus Dostinex tablets, on 24 healthy Egyptian volunteers. The total analysis time was 5.5 min for each sample which permits analysis of various samples per day. The linearity range was from 2.00 to 200.00 pg/mL for CAB. LOD and LOQ were found to be 0.5 and 1.6 pg/mL, respectively. The final greenness numerical value was 0.63 using AGREE tool. The results of pharmacokinetic parameter Tmax were 2.17, and 2.33 h; for test and reference products, respectively. The generic formulation of test product is considered bioequivalent to the reference product Dostinex 0.5 mg tablets and satisfies the requirements of the Egyptian market. The merits of the method over the previous published methods are low cost; availability of cheap internal standard; rapidness; use of acetonitrile-free solvents mobile phase.