Performance Liquid Chromatography-ultraviolet Method Research Articles

Eco-friendly micellar HPLC approach for simultaneous estimation of combination therapy for hidradenitis suppurativa: Applications to spiked human plasma and different dosage forms.

This study introduces a new method for analyzing rifampicin, moxifloxacin, and metronidazole using a green micellar High Performance Liquid Chromatography-Ultraviolet method in bulk drugs, different commercial formulations, and spiked human plasma. The combined therapy of these three broad-spectrum antibiotics is used to cure refractory hidradenitis suppurativa (HS), an inflammatory condition affecting the skin. The sustainable separation was attained on a reversed-phase C18 Kinetex® column maintained at ambient temperature in less than 5 min. The mobile phase comprises 0.1 M sodium dodecyl sulfate (SDS) in water, pH 3.5, adjusted using o-phosphoric acid, and 10% n-butanol. The flow rate was 1 mL/min, with 10 μL injection volume and UV detection at 230 nm. The impact of three key significant variables, SDS concentration, n-butanol percentage, and the mobile phase pH, on suitability parameters was studied. ICH and FDA guidelines were committed to when validating the technique. The results showed linear calibration graphs with high precision and accuracy, in both pure and spiked plasma. The method is efficient, easy to use, and has a high sample throughput, making it suitable for routine analysis in the quality control department and therapeutic monitoring. It is also evaluated as a green-and-white substitute for traditional reported methods.

High performance liquid chromatography Ultraviolet method for the determination of fludioxonil fungicide residues: Application on rice grains cultivated in Pakistan

An analytical method was developed and validated for the determination of fludioxonil in rice samples. Rice samples for the study were collected from different regions of Pakistan. The method was based on safe and cost-effective extraction of fludioxonil from rice grains using acetone and methanol (1:1), efficient clean-up through homogenous mixture of acidic aluminium (12 g) and activated charcoal (1 g) followed by liquid chromatographic determination with UV detection. Quantification was performed on Prospher Star C18 (5 µm, 25 × 0.46 cm) column maintaining the temperature 40 °C and detector wavelength 212 nm using mobile phase 50:50 v/v methanol-water (pH 3.3) employing flow rate 1.0 mL min −1 and 20 µL injection volume. The method showed linearity (0.01–16 mg −1 ) with correlation coefficient greater than 0.998. The proposed method was precisely validated for rice sample of all regions, showing recoveries higher than 98%. Rice samples collected from Badin, Multan, Hyderabad, Lahore, Jahania and Sarghoda was found to have fludioxonil residues 0.046, 0.045, 0.043, 0.040, 0.024 and 0.016 mg Kg −1 respectively, all below the maximum residual limit (MRL) level i.e. 0.05 mg Kg −1 whereas samples collected from Khanewal and Gularchi showed fludioxonil residue above MRL i.e. 0.065 and 0.058 mg Kg −1 respectively. However, fludioxonil residues was not detected in rice sample collected from city Makhdumpur.

Simultaneous quantification of ondansetron and tariquidar in rat and human plasma using a high performance liquid chromatography-ultraviolet method.

Ondansetron, a widely used antiemetic agent, is a P-glycoprotein (P-gp) substrate and therefore expression of P-gp at the blood-brain barrier limits its distribution to the central nervous system (CNS), which was observed to be reversed by coadministration with P-gp inhibitors. Tariquidar is a potent and selective third-generation P-gp inhibitor, and coadministration with ondansetron has shown improved ondansetron distribution to the CNS. There is currently no reported bioanalytical method for simultaneously quantifying ondansetron with a third-generation P-gp inhibitor. Therefore, we aimed to develop and validate a method for ondansetron and tariquidar in rat and human plasma samples. A full validation was performed for both ondansetron and tariquidar, and sample stability was tested under various storage conditions. To demonstrate its utility, the method was applied to a preclinical pharmacokinetic study following coadministration of ondansetron and tariquidar in rats. The presented method will be valuable in pharmacokinetic studies of ondansetron and tariquidar in which simultaneous determination may be required. In addition, this is the first report of a bioanalytical method validated for quantification of tariquidar in plasma samples.

Pharmacokinetics and Tissue Residence of Various Doses of Levamisole in Crucian Carp at Different Water Temperatures

The pharmacokinetics of levamisole in crucian carp, including the absorption, distribution, and clearance rates in different tissues, were studied at different temperatures and doses for the theoretical basis of proper usage and withdrawal time. The fish were divided into three groups denoted A, B and C. The A and B groups were treated once at a dosage of 5 mg/kg levamisole, at 19 ± 1°C and 26 ± 1°C water temperature, respectively. The C group was treated at a dosage of 20 mg/kg levamisole at 19 ± 1°C water temperature. Then plasma, muscle, hepatopancreas, and kidney tissues samples were collected and pretreated, then measured using an ultra performance liquid chromatography-ultraviolet method. Plasma data were analyzed using DAS 3.0 pharmacokinetics software. Total area under the curve (AUC0-t) and elimination half-life (t1/2z) had a negative correlation with water temperature, and a positive correlation with dosage. Apparent volume of distribution (Vz) and total clearance rate (CLz) was positively correlated with temperature, and a negatively correlated with dosage. Levamisole was absorbed quickly to reach its peak concentration. The drug concentration and residence time in hepatopancreal and kidney were considerably higher and longer respectively than in the muscle and plasma suggesting that the hepatopancreas and kidney may be important metabolic organs for levamisole.

Determination and comparative analysis of 13 nucleosides and nucleobases in natural fruiting body of Ophiocordyceps sinensis and its substitutes

ABSTRACTNucleosides and nucleobases are one of the most important indicators of quality control. A sensitive and reliable high performance liquid chromatography-ultraviolet method was applied to analyse 13 nucleosides and nucleobases simultaneously in 15 batches of nine Ophiocordyceps species and its allies in China. Principal component analysis (PCA) and cluster analysis were conducted by SPSS 22.0 software (IBM Corp., Armonk, NY, USA). The 15 samples of Cordyceps were differentiated successfully based on their nucleoside and nucleobase content. Total nucleosides content in mycelium was significantly higher than that in the natural fruiting bodies of Ophiocordyceps sinensis (NFOS). Five nucleosides or nucleobases – adenine (A), guanosine (Gu), uracil (U), uridine (Ur) and guanine (G) – were the major components contributed to the total variance according to PCA. The profiles of the 13 tested nucleosides and nucleobases (including adenosine, cytidine, guanosine, inosine, thymidine, uridine, cordycepin, adenine, cytosine, guanine, thymine, uracil and hypoxanthine) can discriminate different samples and can be candidate indicators applied for the quality control of Ophiocordyceps and its allies.

Rapid Quantitative Analysis of Naringenin in the Fruit Bodies of Inonotus vaninii by Two-phase Acid Hydrolysis Followed by Reversed Phase-high Performance Liquid Chromatography-ultra Violet.

Introduction:Sanghuang is one of mystical traditional Chinese medicines recorded earliest 2000 years ago, that included various fungi of Inonotus genus and was well-known for antitumor effect in modern medicine. Inonotus vaninii is grown in natural forest of Northeastern China merely and used as Sanghuang commercially, but it has no quality control specification until now. This study was to establish a rapid method of two-phase acid hydrolysis followed by reversed phase-high performance liquid chromatography-ultra violet (RP-HPLC-UV) to quantify naringenin in the fruit body of I. vaninii.Materials and Methods:Sample solution was prepared by pretreatment of raw material in two-phase acid hydrolysis and the hydrolysis technology was optimized. After reconstitution, analysis was performed using RP-HPLC-UV. The method validation was investigated and the naringenin content of sample and comparison were determined.Results:The naringenin was obtained by two-phase acid hydrolysis method, namely, 10.0 g of raw material was hydrolyzed in 200 mL of 1% sulfuric acid aqueous solution (v/v) and 400 mL of chloroform in oil bath at 110°C for 2 h. Good linearity (r = 0.9992) was achieved between concentration of analyte and peak area. The relative standard deviation (RSD) of precision was 2.47% and the RSD of naringenin contents for repeatability was 3.13%. The accuracy was supported with recoveries at 96.37%, 97.30%, and 99.31%. The sample solution prepared using the proposed method contained higher content of naringenin than conventional method and was stable for 8 h.Conclusion:Due to the high efficiency of sample preparation and high reliability of the HPLC method, it is feasible to use this method for routine analysis of naringenin in the fungus.SUMMARY A convenient two-phase acid hydrolysis was employed to produce naringenin from raw material, and then an efficient and reliable reversed phase-high performance liquid chromatography-ultra violet method was established to monitor naringenin in the fruit bodies of Inonotus vaninii. The newly established method could be used to control the quality of the herb. Abbreviations used: RP-HPLC-UV: Reversed Phase-High Performance Liquid Chromatography-Ultra Violet, RSD: Relative Standard Deviation, EtOAc: Ethyl acetate, ACN: Acetonitrile, MeOH: Methanol, RH: Relative Humility.

Optimization and validation of high performance liquid chromatography-ultra violet method for quantitation of metoprolol in rabbit plasma: application to pharmacokinetic studies

Purpose: To develop a sensitive, simple and validated high performance liquid chromatography (HPLC) analytical method for the determination of metoprolol tartrate in rabbit plasma. Methods: Mobile phase of methanol and 50 mM ammonium dihydrogen phosphate solution (50:50) at pH 3.05 was used for separation of metoprolol on BDS hypersil C18 column at a wavelength of 223 nm. Flow rate and retention time were 0.6 mL/min and 7.4 min, respectively. For pharmacokinetic study, rabbits were given an oral dose of 8 mg/kg of metoprolol in solution form. Blood samples were taken from jugular vein of the rabbits after drug administration and analysed by HPLC. Results: Separation of metoprolol was not interfered with other components in plasma. The calibration curve was linear in the range of 25 - 1000 ng/mL (r 2 = 0.997). Lower limits of detection (LLOD) and quantitation (LLOQ) were 8.87 and 25 ng/mL, respectively. Relative standard deviation (RSD) of intraday and inter-day precision was < 14.27 and 7.61 %, respectively. Relative error of accuracy was between 4.85 and 14.37 %. Maximum plasma concentration (C max ), time to maximum plasma concentration (T max ) and half-life (t½) after metoprolol oral administration in rabbits were 186.29 ng/mL, 0.50 h and 2.27 h, respectively. Conclusion: A simple, accurate and precise HPLC-UV method for metoprolol determination in rabbit plasma has been successfully developed and applied to a pharmacokinetic study. Keywords: HPLC-UV, Metoprolol, Pharmacokinetics, Rabbit plasma, Liquid-liquid extraction, Validation

Method Validation for Simultaneous Determination of Pesticide Residues in Post-Mortem Samples by High Performance Liquid Chromatography-Ultraviolet Method

Method Validation for Simultaneous Determination of Pesticide Residues in Post-Mortem Samples by High Performance Liquid Chromatography-Ultraviolet Method

Development and validation of an HPLC-UV method for pazopanib quantification in human plasma and application to patients with cancer in routine clinical practice.

Pazopanib, a new oral angiogenesis inhibitor, has demonstrated clinical activity against multiple solid tumors and was approved for the treatment of patients with advanced renal cell carcinoma. As an exposure-response relationship has been observed for pazopanib, its therapeutic drug monitoring could be a valuable tool in clinical practice. Therefore, the aim of this study was to develop and validate a selective and precise high performance liquid chromatography-ultraviolet method for the measurement of pazopanib in plasma from patients with cancer. After liquid-liquid extraction with diethyl ether, pazopanib and gefitinib (internal standard) were separated using isocratic elution on an Ultrabase C18 column using a mobile phase consisting of a mixture in vol/vol proportion of 47:53 of ammonium acetate (pH, 7; 0.02 mol/L) and acetonitrile/methanol (70:30, vol/vol) pumped at a constant flow rate of 1 mL/min. Quantification was performed at 260 nm. Method validation was undertaken as per the guidelines for Bioanalytical Method Validation published by the Food and Drug Administration and European Medicines Agency. Calibration curves were linear over the range 0.5-100 mcg/mL. Interday and intraday coefficients of variations were less than 4.5%. The limit of detection and the lower limit of quantification were 0.2 and 0.5 mcg/mL, respectively. Recovery of pazopanib from plasma was >80%. This is the first high performance liquid chromatography-ultraviolet method for pazopanib quantification that has been validated within a wide range of plasma concentrations and is a suitable method for therapeutic drug monitoring of pazopanib.

PARAFAC based methods for the analysis of Diltiazem drug excitation emission matrices of fluorescence obtained by a derivatization reaction

A fluorescent derivatization reaction for Diltiazem drug quantification based on the condensation reaction of citric or malonic acid with acetic anhydride, catalyzed by the tertiary amine group of Diltiazem, was developed. Excitation emission matrices (EEMs) of fluorescence of the pure solvent (ethanol), standard and sample solutions following a standard addition methodology were analysed by PARAFAC based methods (PARAFAC, PARAFAC2 and PARALIND) to obtain robust calibration methodologies. The quantification results of the sample were compared with the official US Pharmacopeia high performance liquid chromatography-ultraviolet method (USP HPLC-UV). Although the experimental sets of EEM show linearity deviations all the PARAFAC based methods allow correct robust estimation of Diltiazem concentration in pharmaceutical formulations. The closest results were: derivatization with citric acid and PARAFAC2 six components non-negativity constraint model with a detection limit of 0.088 ppm; and, derivatization with malonic acid and PARAFAC six components non-negativity constraint model with a detection limit of 0.066 ppm for the malonic acid was observed. The simultaneous utilization of the three PARAFAC methods gives further information about the intrinsic structure of the data sets under analysis, i.e., it works as an efficient diagnostic tool for the existence of non-linearity and colinearity.

Phase II trial of nolatrexed dihydrochloride [ThymitaqTM, AG 337] in patients with advanced hepatocellular carcinoma

To evaluate the tolerability and efficacy of nolatrexed in patients with advanced hepatocellular carcinoma. Forty-eight patients were entered onto this study. Nolatrexed was administered every 3 weeks as a 24-h continuous intravenous infusion of 725 mg/m(2)/day for 5 days. Doses were adjusted to maintain a dose level that produced > or = grade 2 toxicity. Response was assessed after every two cycles. Plasma pharmacokinetic samples were assayed using a validated high performance liquid chromatography ultraviolet method. Thirty-nine (81%) patients were evaluable for response. The mean number of cycles received was 2.8 (range 1-12). The mean dose intensity was 700 mg/m(2)/day (SD of 71). One patient had a partial response (2.6%) for 7 months. Eighteen (46%) patients had SD, 20 (51%) patients had progressive disease. The median duration of SD was 93 days. The median overall survival was 32 weeks [95% CI (22-37)]. The most frequent Grade 3 or 4 adverse events were stomatitis (25%), dehydration (23%) and asthenia (21%). There was no evidence of cumulative toxicity. The overall median plasma concentration (C (max)) was 14.20 microg/mL (range 1.41 to 119 microg /mL) with no accumulation observed between cycles 1-6. This phase II study of nolatrexed in advanced HCC patients, demonstrated minimal activity and significant stomatitis. Hence, it does not warrant further study as a single agent for this disease.