Development and validation of liquid chromatography-tandem mass spectrometric method for the quantification of ciprofibrate from human plasma.

A new rapid, selective and sensitive liquid chromatography-tandem mass spectrometric method was developed and validated for the determination of ciprofibrate, an antihyperlipidemic agent, in K2EDTA human plasma. Furosemide was used as internal standard (IS). The ciprofibrate and IS were extracted using Oasis HLB 1 cc 30 mg solid-phase extraction cartridge. The chromatographic separation was performed on ACE C18, 50 × 4.6 mm, 5 µm column. The mobile phase consisted of 0.001% ammonia in methanol-acetonitrile-water (70:20:10, v/v/v). Detection and quantitation were performed by a triple quadrupole equipped with electrospray ionization and multiple reaction monitoring in negative ionization mode. The most intense [M-H](-) transition for ciprofibrate at m/z 287.0 → 85.0 and for IS at m/z 328.9.0 → 204.9 were used for quantification. The method was found to linear over the range of 25-30,000 ng/mL (r > 0.998). The lower limit of quantitation (LLOQ) was 25 ng/mL. The extraction recovery was above 90%. The accuracy was found to be 101.26-106.44%. The stability testing was also investigated and it was found that both drug and IS were quite stable. The developed method was successfully applied to the bioequivalence study of ciprofibrate 100 mg tablet after oral administration to healthy human volunteers.

Comparative cardiometabolic effects of fibrates and omega-3 fatty acids.

Even with the aggressive reduction of low-density lipoprotein cholesterol by statin therapy, a high residual risk of cardiovascular events remains substantially and attracts attention to the need for additional preventive therapies. Therefore, effective reductions of residual risk of cardiovascular disease have emerged as therapeutic targets. Fibrates and omega-3 fatty acids have been introduced to reduce triglycerides and to increase high-density lipoprotein cholesterol and have shown anti-atherosclerotic, vascular and metabolic effects. However, some effects are controversial and very recent randomized clinical trials report different results from the earlier ones. In this review, we address the vascular and metabolic effects and the results of recent clinical trials of fibrates and omega-3 fatty acids. We also compared their effects under modern guideline therapy regarding potential drugs to reduce a residual cardiometabolic risk of cardiovascular disease.

Ciprofibrate quantification in human plasma by high-performance liquid chromatography coupled with electrospray tandem mass spectrometry for pharmacokinetic studies.

A rapid, sensitive and specific method for quantifying ciprofibrate in human plasma using bezafibrate as the internal standard (IS) is described. The sample was acidified prior extraction with formic acid (88%). The analyte and the IS were extracted from plasma by liquid-liquid extraction using an organic solvent (diethyl ether/dichloromethane 70/30 (v/v)). The extracts were analyzed by high performance liquid chromatography coupled with electrospray tandem mass spectrometry (HPLC-MS/MS). Chromatography was performed using Genesis C18 4 µm analytical column (4.6 × 150 mm i.d.) and a mobile phase consisting of acetonitrile/water (70/30, v/v) and 1mM acetic acid. The method had a chromatographic run time of 3.4 min and a linear calibration curve over the range 0.1-60 µg/mL (r>0.99). The limit of quantification was 0.1 µg/mL. The intra- and interday accuracy and precision values of the assay were less than 13.5%. The stability tests indicated no significant degradation. The recovery of ciprofibrate was 81.2%, 73.3% and 76.2% for the 0.3, 5.0 and 48.0 ng/mL standard concentrations, respectively. For ciprofibrate, the optimized parameters of the declustering potential, collision energy and collision exit potential were -51 V, -16 eV and -5 V, respectively. The method was also validated without the use of the internal standard. This HPLC-MS/MS procedure was used to assess the bioequivalence of two ciprofibrate 100mg tablet formulations in healthy volunteers of both sexes. The following pharmacokinetic parameters were obtained from the ciprofibrate plasma concentration vs. time curves: AUC(last), AUC(0-168 h), C(max) and T(max). The geometric mean with corresponding 90% confidence interval (CI) for test/reference percent ratios were 93.80% (90% CI=88.16-99.79%) for C(max,) 98.31% (90% CI=94.91-101.83%) for AUC(last) and 97.67% (90% CI=94.45-101.01%) for AUC(0-168 h). Since the 90% CI for AUC(last), AUC(0-168 h) and C(max) ratios were within the 80-125% interval proposed by the US FDA, it was concluded that ciprofibrate (Lipless 100mg tablet) formulation manufactured by Biolab Sanus Farmacêutica Ltda. is bioequivalent to the Oroxadin (100 mg tablet) formulation for both the rate and the extent of absorption.