LC-MS/MS method for simultaneous estimation of raloxifene, cladrin in rat plasma: application in pharmacokinetic studies

Aim: A newer LC-MS/MS method was developed and validated for the simultaneous quantification of raloxifene (RL) and cladrin (CL). Methodology: Both drugs were resolved in RP-18 (4.6 x 50 mm, 5 mu) Xbridge Shield column using acetonitrile and 0.1% aqueous solution of formic acid (FA) (70:30% v/v) as mobile phase by using biological matrices in female Sprague-Dawley rats using-MS/MS. Results: The developed method was found to be linear over the concentration ranges of 1-600 ng/ml, and lower limit of quantification was 1 ng/ml for RL and CL, respectively. Pharmacokinetic results of RL+CL showed C-max = 4.23 +/- 0.61, 26.97 +/- 1.14 ng/ml, at T-max(h) 5.5 +/- 1.00 and 3.5 +/- 1.00, respectively. Conclusion: Pharmacokinetic study results will be useful in the future for the combined delivery of RL and CL for osteoporosis treatment. [GRAPHICS] .