Microemulsion liquid chromatographic method for simultaneous determination of simvastatin and ezetimibe in their combined dosage forms

Accumulation and risk assessment of metals in palm oil cultivated on contaminated oil palm plantation soils

Anthropogenically polluted soils with metals are detrimental to human life. The present study assessed the concentration of metals in soil and the risks associated with the consumption of the metals when transferred from soil to palm oil. The metals of interest were Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn. Analysis was done on metals in soil and virgin palm oil from fifteen independent sampling locations in the southern states of Nigeria, which includes the Nigeria Institute for Oil Palm Research (NIFOR) and its substations. Top soils were collected at a depth of 0-15 cm and virgin palm oil in 1 litre container by grab sampling method. The method proposed was to achieve high throughput with minimal mobile phase solvent. Micro emulsion technique was involved as sample preparation method for the extraction of metals in virgin palm oil from the matrix. Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES) was used to analyse metals in virgin palm oil and soil. This reduces analysis time and does not require complex sample preparation. Zinc metal recorded the highest concentration of metal in the palm oil and Chromium metal recorded the highest concentration of metal in soil. There was a correlation between the accumulations of metals from soil to palm oil. Risk was assessed using various indices. Cadmium metal recorded the highest concentration in the Target Hazard Quotient (THQ), Accumulation Factor (AF) and Health Risk Index (HRI). Daily Intake of Metals (DIM) was highest for Chromium metal. Cadmium was the highest accumulator of metals in the palm oil.

Cetyl-alcohol-reinforced hollow fiber solid/liquid-phase microextraction and HPLC-DAD analysis of ezetimibe and simvastatin in human plasma and urine

A new cetyl-alcohol-reinforced hollow fiber solid/liquid-phase microextraction (CA-HF-SLPME) followed by high-performance liquid chromatography-diode array detection (HPLC-DAD) method was developed for simultaneous determination of ezetimibe and simvastatin in human plasma and urine samples. To prepare the CA-HF-SLPME device, the cetyl-alcohol was immobilized into the pores of a 2.5 cm hollow fiber micro-tube and the lumen of the micro-tube was filled with 1-octanol with the two ends sealed. Afterwards, the prepared device was introduced into 10 mL of the sample solution containing the analytes with agitation. Under optimized conditions, calibration curves plotted in spiked plasma and urine samples were linear in the ranges of 0.363-25/0.49-25 μg L^-1 for ezetimibe/simvastatin and 0.193-25/0.312-25 μg L^-1 for ezetimibe/simvastatin in plasma and urine samples, respectively. The limit of detection was 0.109/0.174 μg L^-1 for ezetimibe/simvastatin in plasma and 0.058/0.093 μg L^-1 for ezetimibe/simvastatin in urine. As a potential application, the proposed method was applied to determine the concentration of selected analytes in patient plasma and urine samples after medication and satisfactory results were achieved. In comparison with reference methods, the CA-HF-SLPME-HPLC-DAD method demonstrates considerable potential in the biopharmaceutical analysis of selected drugs.

Development and Validation of an LC-MS-MS Method for the Simultaneous Determination of Simvastatin, Simvastatin Acid and Ezetimibe in Human Plasma and Its Application to Pharmacokinetic Study in the Indian Population

A simple, selective, sensitive and high-throughput liquid chromatography-tandem mass spectrometry (LC-MS-MS) method has been developed and validated for the simultaneous quantification of simvastatin (SS), simvastatin acid (SSA, active metabolite of SS) and ezetimibe (EZM) in K2 EDTA containing human plasma, using simvastatin D6, simvastatin acid D3 and ezetimibe D4 as internal standards (ISTDs), respectively. A volume of plasma sample of only 400 µL was processed by the solid phase extraction technique; then 20 µL of processed sample was run on a Phenomenex, Kinetix XB C18, 150 × 4.6 mm, 5 µm column using an isocratic mobile phase consisting of 10 mM ammonium formate buffer (pH 4.0 ± 0.3): acetonitrile (27 : 73, v/v) with a run time of 6.3 min. The precursor and product ions of SSA, EZM and their ISTDs were monitored on a triple quadrupole instrument operated in the negative ionization mode, and SS was monitored in the positive mode. The method was validated over a concentration range of 0.2-80 ng/mL for SS, 0.1-60 ng/mL for SSA and 0.05-15 ng/mL for EZM. The method has been successfully applied in clinical pharmacokinetic study in the Indian population. The Cmax, AUC0-inf and Tmax values obtained in our study were 10.61 ± 5.287, 77.58 ± 29.367 and 1.62 ± 0.436 for EZM; 69.74 ± 45.274, 190.71 ± 107.271 and 1.74 ± 0.480 for SS; and 25.36 ± 23.576, 139.24 ± 131.653 and 3.95 ± 0.671 for SSA, respectively.

Validated UPLC-MS/MS method for simultaneous determination of simvastatin, simvastatin hydroxy acid and berberine in rat plasma: Application to the drug-drug pharmacokinetic interaction study of simvastatin combined with berberine after oral administration in rats

A rapid and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) assay method was developed and validated for simultaneous quantification of simvastatin (SV), its metabolite simvastatin hydroxy acid (SVA) and berberine (BBR) in rat plasma. Separation was performed on Poroshell 120 EC-C18 column (4.6×50mm, 2.7μm) using gradient elution by mobile phase containing acetonitrile and 10mM ammonium acetate (pH 4.5). Polarity switch (positive-negative-positive ionization mode) was performed in a total run time of 4.0min. The lower limits of quantification (LLOQ) for SV, SVA and BBR were 0.10, 0.20 and 0.10ng/mL, respectively. The response function was established for concentration range of 0.10-100ng/mL for SV and BBR and 0.20-3000ng/mL for SVA, with a coefficient of correlation of >0.99 for all the compounds. The proposed method was applied to the drug-drug pharmacokinetic interaction study of SV combined with BBR after oral administration in rats.