Improved gas chromatographic-mass spectrometric method for the quantitative determination of vinpocetine in human plasma

First report on the electrooxidation of vinpocetine using a modification free sensing platform: application to pharmaceutical formulations

This study presents the first insights into vinpocetine (VIN) behavior, a nootropic compound, on a glassy carbon electrode (GCE). Cyclic voltammetry (CV) revealed an irreversible oxidation peak at +1.0 V (vs. Ag/AgCl), with pH dependency indicating proton involvement in the electrochemical reaction. Density functional theory (DFT) optimized VIN's molecular geometry, while Fukui functions and dual descriptors elucidated its reactivity for a more straightforward exploration of the complete electrooxidation mechanism. Differential pulse voltammetry (DPV) demonstrated VIN sensing capabilities within a concentration range of 0.20 to 12.8 mg L-1, with a theoretical limit of detection (LOD) at 0.07 mg L-1, using optimized conditions of supporting electrolyte. The method showed selectivity in the presence of excipients and interfering species commonly found in pharmaceutical formulations. Recovery tests yielded 95.5% (n = 3), and quantification in pharmaceutical formulations showed no significant differences compared to the reference method based on HPLC DAD. This novel electroanalytical method holds promise for VIN nootropic sensing and routine pharmaceutical analysis.

Effect of different doses of borneol on the pharmacokinetics of vinpocetine in rat plasma and brain after intraocular administration

The effect of different doses of borneol on the pharmacokinetics of vinpocetine after intraocular administration in the rat plasma and the brain was investigated.Intraocular administration of vinpocetine (3 mg/kg) was performed, in combination with different doses (0, 5, 10, and 20 mg/kg) of borneol. Intravenous administration of vinpocetine was used as a control (1 mg/kg). The concentrations of vinpocetine in the rat plasma and the brain were determined using a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. Using the non-compartmental models with the DSA 2.0 software, the main pharmacokinetics parameters and the brain-targeting effect evaluated.In comparison with intravenous administration, after intraocular administration of vinpocetine alone, the absolute bioavailability (F) of vinpocetine was 43.82% for the plasma, and the drug target index (DTI) was 1.05 for the brain. After intraocular administration of vinpocetine combined with different doses of borneol, the relative bioavailability (Fr) of vinpocetine in the plasma was increased by 130.46-182.90%. The relative bioavailability (Fr) of vinpocetine in the brain was improved (147.19-225.36%). The DTI was 1.12, 1.18, and 1.21 for 5, 10, and 20 mg/kg of borneol, respectively.Compared with the intraocular administration of vinpocetine alone, the co-administration of different doses of borneol resulted in an obvious brain targeting effect.

Identification and quantification of vinpocetine and picamilon in dietary supplements sold in the United States

Vinpocetine and picamilon are drugs prescribed in many countries to treat a variety of cerebrovascular disorders. In the United States, vinpocetine and picamilon have never been approved by the US Food and Drug Administration, but they are both available for sale directly to consumers as dietary supplements. We designed our study to determine the accuracy of supplement labels with regard to the presence and quantity of vinpocetine and picamilon. A validated ultra-high performance liquid chromatography-photodiode-array method was developed for the quantification of vinpocetine and picamilon. The separation was achieved using a reversed phase (C-18) column, photodiode array detection, and water/acetonitrile as the mobile phase. Vinpocetine and picamilon were detected at concentrations as low as 10 and 50 ng/mL, respectively. The presence of vinpocetine and picamilon was confirmed using reference standards. Twenty-three supplements labelled as containing vinpocetine were available for sale at two large supplement retail chains; 17 contained vinpocetine with quantities ranging from 0.3 to 32 mg per recommended daily serving. No vinpocetine was detected in six of the sampled supplements. The supplement label implied that vinpocetine was a constituent of lesser periwinkle in three of the supplements. Of the 31 picamilon supplements available for sale from a variety of retailers: 30 contained picamilon in quantities ranging from 2.7 to 721.5 mg per recommended daily serving. We found that consumers cannot obtain accurate information from supplement labels regarding the presence or quantity of vinpocetine and picamilon. Copyright © 2015 John Wiley & Sons, Ltd.

Development and Validation of RP-HPLC Method for Quantitative Estimation of Vinpocetine in Pure and Pharmaceutical Dosage Forms

A simple, precise, specific, and accurate reversed phase high performance liquid chromatographic (RP-HPLC) method was developed and validated for determination of vinpocetine in pure and pharmaceutical dosage forms. The different analytical performance parameters such as linearity, accuracy, specificity, precision, and sensitivity (limit of detection and limit of quantitation) were determined according to International Conference on Harmonization ICH Q2 (R1) guidelines. RP-HPLC was conducted on Zorbax C18 (150 mm length × 4.6 mm ID, 5 μm) column. The mobile phase was consisting of buffer (containing 1.54% w/v ammonium acetate solution) and acetonitrile in the ratio (40 : 60, v/v), and the flow rate was maintained at 1.0 mLmin−1. Vinpocetine was monitored using Agilent 1200 series equipped with photo diode array detector (λ = 280 nm). Linearity was observed in concentration range of 160–240 μgmL−1, and correlation coefficient was found excellent (R2 = 0.999). All the system suitability parameters were found within the range. The proposed method is rapid, cost-effective and can be used as a quality-control tool for routine quantitative analysis of vinpocetine in pure and pharmaceutical dosage forms.

New HPLC–MS method for quantitative determination of apovincaminic acid in human plasma

A fast and sensitive HPLC-MS method for the quantification of apovincaminic acid, a vinpocetine metabolite, in human plasma has been developed and validated. After protein precipitation with methanol, 10 mL of supernatant was injected at 45 degrees C onto a Zorbax SB-C18 column. Elution was performed in less than three minutes with water containing 0.2% formic acid and acetonitrile (80:20) at 0.75 mL/min. A linearity domain between 4 and 240 ng/mL and a limit of quantification of 4 ng/mL apovincaminic acid were established by monitoring the signal corresponding to m/z = 323. Accuracy and precision were less than 5.2% for within-run assay and 10% for between-run assay. The method was successfully applied in a bioequivalence study of two pharmaceutical products containing 5 mg vinpocetine.

Spectrophotometric and liquid chromatographic determination of fenofibrate and vinpocetine and their hydrolysis products

Several spectrophotometric and HPLC methods are presented for the determination of fenofibrate, vinpocetine and their hydrolysis products. The resolution of either fenofibrate or vinpocetine and their hydrolysis products has been accomplished by using numerical spectrophotometric methods as partial least squares (PLS-1) and principal component regression (PCR) applied to UV spectra; and graphical spectrophotometric methods as first derivative of ratio spectra (1DD) or first (1D) and second (2D) derivative spectrophotometry for vinpocetine and fenofibrate, respectively. In addition HPLC methods were developed using ODS column with mobile phase consisting of acetonitrile-water (80:20, v/v, pH 4) with UV detection at 287 nm for fenofibrate and a mobile phase consisting of acetonitrile-10 mM KH2PO4, containing 0.1% diethylamine (60:40, v/v, pH 4.6) with UV detection at 270 nm for vinpocetine. The proposed methods were successfully applied for the determination of each drug and its hydrolysis product in laboratory-prepared mixture and pharmaceutical preparation. The proposed HPLC and derivative spectrophotometric methods were used to investigate the kinetics of acidic and alkaline hydrolytic processes of each drug. The pH-rate profile of hydrolysis of each drug in Britton-Robinson buffer solutions was studied.