Chromatography-photodiode Array Detection Method Research Articles

UPLC-PDA Approach for Simultaneous Quantification of Elvitegravir, Tenofovir, Emtricitabine and Cobicistat in Tablets: An MS-ESI Study for Degradation Products.

A simultaneous ultra-performance liquid chromatography photodiode array detection method was developed and validated for Elvitegravir, Tenofovir and Emtricitabine and Cobicistat drugs in tablet dosage forms. Effective liquid chromatographic quantification was achieved using a Luna C18 (100 × 2.6mm, 1.6μ) column with an acetonitrile: 0.1% v/v trifluoro acetic acid (80:20% v/v) mobile phase and a photo diode array detector at 260nm for a shorter run time of 3min. The respective retention times for Elvitegravir, Tenofovir, Emtricitabine and Cobicistat were 0.311, 0.792, 1.379 and 2.045min. The range of linearity was 37.50-225.00, 2.50-15.00, 50.00-300.00and 37.50-225.00μg/mL for Elvitegravir, Tenofovir, Emtricitabine and Cobicistat, respectively. A mass spectrometer was employed for quantitative analysis using electron spray ionization multiple reaction monitoring in positive mode. The developed method was validated for different parameters to meet the acceptance criteria as per ICH Q2 (R1) guidelines. Using UPLC-ESI-MS, 12 degradants were identified and their mechanisms were studied.

Pharmacokinetics and Pharmacodynamic Herb-Drug Interaction of Piperine with Atorvastatin in Rats.

Herbals that are widely consumed as therapeutic alternatives to conventional drugs for cardiovascular diseases, may lead to herb-drug interactions (HDIs). Atorvastatin (ATR) is drug of choice for hyperlipidemia and is extensively metabolized through CYP3A4 enzyme. Thus, we postulate that concomitant administration of ATR with piperine (PIP, potent inhibitor of CYP3A4 enzyme)/ridayarishta (RID, cardiotonic herbal formulations containing PIP) may lead to potential HDI. A simple, accurate, sensitivehigh-performance liquid chromatography-photodiode array detection method using Kromasil-100 C18 column, mobile phase acetonitrile: 30mM phosphate buffer (55:45v/v) pH4.5 with flow rate gradient programming was developed to study the potential HDI in rats. Method was found to be linear (2-100ng/mL) with Lower Limit of Detection (LLOD) 2ng/mL. The precision (%CV<15%), accuracy (-1.0 to -10% R.E) with recoveries above 90% from rat plasma of ATR and IS were obtained. The pharmacokinetic (PK) interactions studies on co-administration of ATR (8.4mg/kg, p.o.) with PIP (35mg/kg, p.o.), demonstrated a threefold increase in Cmax of ATR (P<0.01) with significant increase in AUC0-t/AUC0-∞ compared to ATR alone indicating potential PK-HDI. However co-administration of RID (4.2mL/kg, p.o.) showed less significant changes (P>0.05) indicating low HDI. The pharmacodynamic effects/interactions study (TritonX-100 induced hyperlipidemic model in rats) suggested no significant alterations in the lipid profile on co-administration of PIP/RID with ATR, indicating that there may be no significant pharmacodynamic interactions.

Application of a fabric phase sorptive extraction-high performance liquid chromatography-photodiode array detection method for the trace determination of methyl paraben, propyl paraben and butyl paraben in cosmetic and environmental samples

A new sample preparation and chromatographic separation method for methyl, propyl and butyl paraben in cosmetic and environmental samples has been developed, based on fabric phase sorptive extraction and high performance liquid chromatography-photodiode array detection.

Quantification of withaferin-A and withanolide-A in diploid (n = 12) and tetraploid cytotypes (n = 24) of “Rassbhary”, Physalis angulata L

During the present study an analytical method based on reverse-phase high performance liquid chromatography photodiode array detection method was developed for simultaneous determination of withaferin-A and withanolide-A in plant parts of two cytotypes (diploid n = 12 & tetraploid n = 24) of Physalis angulata. All the plant parts were extracted in different solvent solutions i.e., acidic [HCl] methanol (i.e., methanol containing 0.3% of HCl), methanol, n-hexane, chloroform. Both the compounds were comparatively analysed. The results revealed that tetraploid cytotype (n = 24) showed the higher composition of both the reference compounds. The method is simple, rapid and provides better resolution can be easily applied to the quantitative analyses of withanolides in plant matrices.

Fabric phase sorptive extraction-high performance liquid chromatography-photo diode array detection method for simultaneous monitoring of three inflammatory bowel disease treatment drugs in whole blood, plasma and urine

This paper reports a novel fabric phase sorptive extraction-high performance liquid chromatography-photodiode array detection (FPSE-HPLC-PDA) method for the simultaneous extraction and analysis of three drug residues (ciprofloxacin, sulfasalazine, and cortisone) in human whole blood, plasma, and urine samples, generally administered in human patients to treat inflammatory bowel disease (IBD).The drugs of interest were well resolved using a Luna C18 column (250 mm × 4.6 mm; 5 μm particle size) in gradient elution mode within 20 min. The analytical method was optimized and validated in the range 0.05–10 μg/mL for whole blood, 0.25–10 μg/mL for human plasma, and 0.10–10 μg/mL for human urine. Blank human whole blood, plasma, and urine were used as the sample matrix for the method development and validation; while methyl-p-hydroxybenzoate was used as the internal standard (IS). Weighted-matrix matched standard calibration curves showed a good linearity up to a concentration of 10 μg/mL. The intra- and inter-day accuracy values (precision and trueness) were found in the range from −10.9% to 12.3%, and the performances of the validated FPSE-HPLC-PDA were further tested on real IBD patient samples.This is the first FPSE procedure applied simultaneously to whole blood, plasma, and urine samples for the determination of residual IBD drugs, which possess a wide range of polarity (logP values ranging from 2.30 for Ciprofloxacin, to 1.66 for Cortisone, and 2.92 for Sulfasalazine). The new approach exhibits high potential for immediate adoptation as a rapid, robust and green analytical tool for future clinical and pharmaceutical applications.

Characterization of a Sea Buckthorn Extract and Its Effect on Free and Encapsulated Lactobacillus casei.

Probiotics are bacteria that can provide health benefits to consumers and are suitable to be added to a variety of foods. In this research, viability of immobilized Lactobacillus casei in alginate with or without sea buckthorn lipid extract were studied during heat treatment and with an in vitro gastrointestinal model. The characterization of the lipid extract was also done using the UV-Vis spectrometry (UV-Vis), high-performance liquid chromatography photodiode array detection method (HPLC-PDA), gas chromatography coupled with mass spectrometry (GS-MS) and Cryo scanning electron microscopy (Cryo-SEM). During heat treatment, the entrapped probiotic cells proved high viability (>6 CFU log/g), even at temperatures above 50 °C. The rich in monounsaturated fatty acids sea buckthorn fraction improved the in vitro digestion passage regarding the probiotic viability. The survival of the probiotic cells was 15% higher after 2 h in the acidic medium of the simulated gastric fluid in the sample where L. casei was encapsulated with the sea buckthorn extract compared with the samples where no extract was added. Thus, this approach may be effective for the future development of probiotic-supplemented foods as foods with health welfare for the consumers.

A fabric phase sorptive extraction-High performance liquid chromatography-Photo diode array detection method for the determination of twelve azole antimicrobial drug residues in human plasma and urine.

This paper reports a novel fabric phase sorptive extraction-high performance liquid chromatography-photodiode array detection (FPSE-HPLC-PDA) method for the simultaneous extraction and analysis of twelve azole antimicrobial drug residues that include ketoconazole, terconazole, voriconazole, bifonazole, clotrimazole, tioconazole, econazole, butoconazole, miconazole, posaconazole, ravuconazole, and itraconazole in human plasma and urine samples. The selected azole antimicrobial drugs were well resolved by using a Luna C18 column (250mm×4.6mm; 5μm particle size) in gradient elution mode within 36min. The analytical method was calibrated and validated in the range from 0.1 to 8μg/mL for all the drug compounds. Blank human plasma and urine were used as the sample matrix for the analysis; while benzyl-4-hydroxybenzoate was used as the internal standard (IS). The limit of quantification of the FPSE-HPLC-PDA method was found as 0.1μg/mL and the weighted-matrix matched standard calibration curves of the drugs showed a good linearity upto a concentration of 8μg/mL. The parallelism tests were also performed to evaluate whether overrange sample can be analyzed after dilution, without compromising the analytical performances of the validated method. The intra- and inter-day precision (RSD%) values were found ≤13.1% and ≤13.9%, respectively. The intra- and inter-day trueness (bias%) values were found in the range from -12.1% to 10.5%. The performances of the validated FPSE-HPLC-PDA were further tested on real samples collected from healthy volunteers after a single dose administration of itraconazole and miconazole. To the best of our knowledge, this is the first FPSE extraction procedure applied on plasma and urine samples for the simultaneous determination of twelve azole drugs possessing a wide range of logKow values (extending from 0.4 for fluconazole to 6.70 of butoconazole) and could be adopted as a rapid and robust green analytical tool for clinical and pharmaceutical applications.

Cytotoxic activity and phytochemical standardization of Lunasia amara Blanco wood extract

ObjectiveTo evaluate the cytotoxic activity of wood extracts of Lunasia amara Blanco (L. amara) and to perform further phytochemical standardization. MethodsThe wood extracts of L. amara were assessed for cytotoxic activity by in vitro tetrazolium bromide (MTT) method against two human cancer cell lines, cervical cancer cells (HeLa) and breast cancer cells (T47D). Thin layer chromatography, Dragendorf, acetic anhydride-sulfuric acid and ferric chloride were used to detect alkaloids, steroids and polyphenols, respectively. Furthermore, quantitative determination of total alkaloid by ultra fast liquid chromatography-photodiode array detection using lunacrine as a marker compound was performed as well. ResultsThe ethyl acetate extract exhibited higher cell-growth inhibition than methanol and n-hexane extracts on HeLa and T47D cancer line cells with the IC50 of 71.15 and 79.04 μg/mL, respectively. Total alkaloid in ethyl acetate extract was counted as (10.46 ± 0.28)% (w/w), while lunacrine determined by ultra fast liquid chromatography-photodiode array detection method was found to be (3.55 ± 0.26)% (w/w). ConclusionsThe high total alkaloid and lunacrine concentration on the extract confirm the potential cytotoxic property of ethyl acetate wood extract of L. amara.

Residue level and dissipation pattern of lepimectin in shallots using high-performance liquid chromatography coupled with photodiode array detection.

Lepimectin, as an emulsifiable concentrate, was sprayed on shallots at the recommended dose rate (10 mL/20 L) to determine its residue levels, dissipation pattern, pre-harvest residue limits (PHRLs), and health risk. Samples were randomly collected over 10 days, extracted with acetonitrile, purified using an amino solid-phase extraction (NH2 -SPE) cartridge and analyzed using a high-performance liquid chromatography-photodiode array detection method. Field-incurred samples were confirmed using ultra-performance liquid chromatography-tandem mass spectrometry. The linearity was excellent, with a determination coefficient (R2 ) of ≥0.9991. The recoveries at two spiking levels (0.2 and 1.0 mg/kg) ranged from 84.49 to 87.64% with relative standard deviations of ≤7.04%. The developed method was applied to field samples grown in separate greenhouses, one located in Naju and one in Muan, in the Republic of Korea. The dissipation pattern was described by first-order kinetics with half-lives of 1.9 (Naju) and 1.7 days (Muan). The PHRL curves indicated that, if the lepimectin residues are <0.18 (Naju) and <0.13 mg/kg (Muan) 5 days before harvest, the residue levels will be lower than the maximum residue limit (0.05 mg/kg) upon harvesting. The risk assessment data indicated that lepimectin is safe for use in the cultivation of shallots, with no risk of detrimental effects to the consumer.

Characterization of madder and garancine in historic French red materials by liquid chromatography-photodiode array detection

Abstract A reverse phase liquid chromatography-photodiode array detection method is developed for the characterization of ancient samples of madder. In the past, modifications of the madder chemical composition were carried out by hydrolysing the plant dye precursors in order to increase its red power, the aim of this transformation being to concentrate the red colour of the matter. After extraction of madder dyes in a water-methanol mixture, different anthraquinonic compounds were identified through the chemical constituents present in a garancine sample and in the two madder species growing in the Mediterranean area: Rubia tinctorum and R. peregrina . These two species comprise alizarin, purpurin, lucidin, rubiadin and pseudopurpurin for aglycones and, lucidin primeveroside, ruberythric acid, galiosin and rubiadin primeveroside for heterosidic precursors. These compounds were identified through retention times and UV spectra in comparison with pure standards. Six ancient materials belonging to the collection of the Roure Museum in Avignon (France) and dating from the nineteenth century are characterized as hydrolysed madder (garancine), synthetic alizarin and R. tinctorum roots. A colorimetric study is performed to compare the colour of each sample according to its chemical composition.

UPLC-PDA Analysis for Simultaneous Quantification of Four Active Compounds in Crude and Processed Rhizome of Polygonum multiflorum Thunb

A novel, rapid and specific ultra performance liquid chromatography-photo diode array detection method was developed for the simultaneous determination of 2,3,5,4′-tetrahydroxystilbene-2-O-β-d-glucoside (TSG), emodin-8-O-β-d-glucoside (EMG), emodin (EM) and physcion (PS). The chromatographic separation was performed on an Acquity BEH C18 column (100 × 2.1 mm i.d., 1.7 μm). The mobile phase was a mixture of 0.3% acetic acid–water and 0.3% acetic acid–acetonitrile employing gradient elution at the flow rate of 0.4 mL min−1. The four compounds behaved linearly in the concentration range between 60.80–3040.00 μg mL−1 (TSG), 0.50–25.00 μg mL−1 (EMG), 2.16–108.00 μg mL−1 (EM) and 1.56–78.00 μg mL−1 (PS), respectively with correlation coefficients >0.999. The precision of the method were below 5% RSD. Recoveries of the four compounds ranged from 95.71 to 102.97%, with RSD values less than 2%.

Analyses of tissues of eight marine species from Atlantic and Pacific coasts for dioxin-like chlorobiphenyls (CBs) and total CBs.

Eight commercially and recreationally important marine species were collected in 1993 and 1994 from several Atlantic and Pacific coastal regions of the contiguous United States. Approximately 700 edible tissue samples (e.g., whole body of mussel, crustacean muscle and hepatopancreas, and fish muscle) were analyzed for dioxin-like chlorobiphenyls (CBs) and other selected CB congeners using a rapid high-performance liquid chromatography photodiode array detection method (HPLC/PDA). Total CBs and toxic equivalents (TEQs) of dioxin-like CBs were also determined. The most abundant congeners measured in these tissues were the moderately chlorinated CBs (e.g., CB 138, 153), with mean concentrations ranging from below the limits of detection (approximately 0.2 ng/g) to 1,500 ng/g, wet weight. Certain dioxin-like CBs (e.g., CBs 77, 105, 118, 126) were also found in several of these samples (mean concentrations ranging from below the limits of detection [approximately 0.4 ng/g] to 680 ng/g). Similar to previous studies, the majority of seafood tissues contained total CB concentrations that were below the U.S. Food and Drug Administration's (FDA) tolerance limit for CBs of 2,000 ng/g, wet weight (2.0 ppm). Furthermore, the majority of samples that contained CB levels below the FDA CB tolerance limit also had CB TEQs that were lower than the FDA's advisory level for TCDD (25 ppt or 25 pg/g, wet weight) in fish from the Great Lakes, which is used in evaluating CB TEQs. Several crustacean hepatopancreas samples collected from certain Atlantic and Pacific urban sites (e.g., Dungeness crab from Elliott Bay in Puget Sound, WA, American lobster from Deer Island in Boston Harbor, MA), however, did contain total CB and CB TEQs that exceeded the FDA CB tolerance and TCDD advisory limits. Mono-ortho- (e.g., CBs 118, 105) and non-ortho-substituted congeners (e.g., CBs 77 and 126) were the largest contributors to the CB TEQs of the hepatopancreas samples that exceeded the action limit.http://link.springer-ny. com/link/service/journals/00244/bibs/37n2p205.html