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Showing papers in "Journal of analytical and bioanalytical techniques in 2010"


Journal ArticleDOI
TL;DR: In this article, a reversed-phase high-performance liquid chromatographic method has been developed and validated for simultaneous estimation of ascorbic and gallic acid in Phyllanthus emblica L. (Euphorbiaceae).
Abstract: A reversed-phase high-performance liquid chromatographic method has been developed and validated for simultaneous estimation of ascorbic and gallic acid in Phyllanthus emblica L. (Euphorbiaceae). A C18 column was used with a gradient elution of methanol and 0.1% (v/v) acetic acid in HPLC-grade water as mobile phase at a flow rate of 0.9 mL min -1 . UV detection was performed at 278 nm. The method was validated for accuracy, precision, linearity, specificity and sensitivity in accordance with International Conference on Harmonisation guidelines. Amounts of ascorbic and gallic acid detected in freeze-dried extract of the plant were 4.58% and 0.59%. Total run time was 50 min. ascorbic and gallic acid was eluted with retention times of 3.60 and 10.77 min respectively. Validation revealed that the method is specific, accurate, precise, reliable and reproducible. Calibration plots were linear over the concentration ranges 30–90 μg mL -1 for ascorbic acid and 5–15 μg mL -1 for gallic acid, respectively. Limits of detection were 1.42 and 1.56 μg mL -1 and limits of quantification were 4.32 and 4.73 μg mL -1 for ascorbic and gallic acid, respectively. Recovery was 99.37 % and 98.68% for ascorbic and gallic acid, respectively and the coefficient of variance was <2.0% for both. In negative ESI mode, the spectra showed the signals at m/z of 174.98 for ascorbic acid and m/z of 168.98 for gallic acid .The high percentage recovery and low coefficient of variation confirm the suitability of the method for simultaneous analysis of ascorbic and gallic acid in Phyllanthus emblica .

58 citations


Journal ArticleDOI
TL;DR: In this article, the HPTLC method was used for simultaneous estimation of Metformin hydrochloride (MET), Atorvastatin (ATV) and Glimepiride (GLM) in tablet dosage forms.
Abstract: This paper describes a new, simple, precise, and accurate HPTLC method for simultaneous estimation of Metformin hydrochloride (MET), Atorvastatin (ATV) and Glimepiride (GLM) as the bulk drug and in tablet dosage forms. Chromatographic separation of the drugs was performed on aluminum plates precoated with silica gel 60 F 254 as the stationary phase and the solvent system consisted of water: methanol: ammonium sulphate (1: 1: 4 v/v/v). Densitometric evaluation of the separated zones was performed at 237 nm. The three drugs were satisfactorily resolved with R F values 0.37 ± 0.02 and 0.59 ± 0.02, 0.75 ± 0.02 for MET, ATV, GLM respectively. The accuracy and reliability of the method was assessed by evaluation of linearity (200-700 ng/spot for MET, 600-2100 ng/spot for ATV and 600-2100 ng/spot for GLM ), precision (intra-day% RSD was 0.54–1.23 and inter-day% RSD was 0.90–1.48 for MET, intra-day% RSD was 0.91–1.74 and inter-day% RSD was 0.56–1.52 for ATV and intra-day% RSD was 0.60–1.27 and inter-day% RSD was 0.96–1.48 for GLM ), accuracy (99.66 ± 0.14 for MET, 98.46 ± 0.40 for ATV and 98.62 ± 0.39 for GLM ), and specificity in accordance with ICH guidelines.

38 citations


Journal ArticleDOI
TL;DR: In this paper, the role of ionization polarity on matrix effect was studied and the matrix factor (MF) was determined to evaluate the matrix effects in different polarities by using ESI-LC-MS/MS.
Abstract: Matrix effect is the effect on an analytical method caused by all other components of the sample except the specific compound to be quantified. Matrix effects and selectivity issues have long been associated with bioanalytical techniques. A number of approaches have been investigated to improve reproducibility and robustness of LC-MS-MS methods that are subjected to matrix effects. In the present research work the role of ionization polarity on matrix effect was studied. Enalapril and its metabolite were analyzed in positive and negative polarity by using ESI-LC-MS/MS. Matrix factor (MF) was determined to evaluate the matrix effects in different polarities. Two different concentration levels of each analyte were used to determine the MF. In positive polarity the MF at two different concentration levels were 0.6353 & 0.6496 for enalapril and 0.6885 & 0.6770 for enalaprilat, whereas, the MF in negative polarity at two different concentration levels were 0.8203 & 0.7717 for enalapril and 1.1124 & 1.0915 for enalaprilat. These data showed approximately 30-35% ion suppression in positive polarity for both the analyte, but approximately 20% ion suppression for enalapril and 10% ion enhancement for enalaprilat in negative polarity. So, matrix effects depend on the ionization polarity also.

21 citations


Journal ArticleDOI
TL;DR: In this paper, the authors investigate the sudden drop of dissolution with respect to higher compression pressure and hardness of tablet with a good and comparative less significant disintegration time and to understand an affect of pressure on drug with regards to compression behavior on dissolution and other properties.
Abstract: The current work aims to investigate the sudden drop of dissolution with respect to higher compression pressure and hardness of tablet with a good and comparative less significant disintegration time and to understand an affect of pressure on drug with respect to compression behavior on dissolution and other properties. Where Cefuroxime Axetil was compressed at different pressure in form of pellets and tablets using hydraulic press and compression machine respectively, and characterized to understand any physical and chemical change using X-ray powder diffraction, differential scanning calorimetry, and Dissolution and Scanning Electron microscopy. Scanning electron microscopy studies of pellets revealed that the change in surface morphology from opaque to translucent clear with increase in breaking force, these different pressure compressed pellets were subjected to uniform reduction of particle size. The similarity factor f2 values of drug release profile were comparably same. The breaking force and pellet hardness had indicated a very firm intrinsic binding force exist with Cefuroxime Axetil, study had investigated the decrease in-vitro dissolution is marked by the compact binding property of individual particles of Cefuroxime Axetil between the excipient due to the increase in compression force.

16 citations


Journal ArticleDOI
TL;DR: In this article, a simple and precise method for the determination of Tinidazole and Ciprofloxacin hydrochloride from its single formulation tablet has been developed using differential pulse polarography.
Abstract: A simple and precise method for the determination of Tinidazole and Ciprofloxacin hydrochloride from its single formulation tablet has been developed using differential pulse polarography. Tinidazole and ciprofloxacin produces a cathodic wave at -0.38 V and -1.30 V respectively versus S.C.E in a solution of pH = 6.5 (Britton Robison buffer). The dynamic range for Tinidazole, is 0.50 to 279.31μgcm -3 and for Ciprofloxacin, it is 24.39 to 245.28 μgcm -3 . The method has been validated and applied successfully for the determination of the two drugs from their respective formulation.

16 citations


Journal ArticleDOI
TL;DR: In this article, an isocratic HPLC method for the stability indicating assay of Glipizide (GPZ), Glibenclamide (GBD) and Glimeperide (GMD) in the presence of Metformin hydrochloride (MET) in pharmaceutical dosage forms using ion pair-reversed phase liquid chromatographic Technique.
Abstract: The present work describes the development and validation of an isocratic HPLC method for the stability indicating assay of Glipizide (GPZ), Glibenclamide (GBD) and Glimeperide (GMD) in the presence of Metformin hydrochloride (MET) in pharmaceutical dosage forms using ion pair-reversed phase liquid chromatographic Technique. The ion pairing agent used was tetrabutyl ammonium hydrogen sulphate (TBHS). The TBHS 0.030 molar solution in water with pH 6.0 used as buffer. The composition of buffer with acetonitrile used was 50:50 (v/v) on reversed phase column bonded with octadecyl silane. The wave length used was 225 nm. The resolution between the closest peaks Glimeperide and Glibenclamide was more than 1.5 and all the three drugs gives a linear response (r2>0.999). The method used for all the three substances were found selective, precise, accurate and robust. The method can be used for quality control assay of the bulk and in finished dosage form as single component and combine with Metformin hydrochloride. The purpose of the method to study individually the stability of Glipizide, Glibenclamide and Glimeperide in the presence of Metformin hydrochloride as any such method is not reported so far.

14 citations


Journal ArticleDOI
TL;DR: In this paper, the robustness of an analytical chromatographic method for separation of cystatin c has been verifi fi ed. The results obtained using mobile phase after 6 months of storage have proven its stability and possibility of use.
Abstract: Robustness of an analytical chromatographic method for separation of cystatin c has been veri fi ed. Changes in many parameters were carried out, such as, wavelength, column oven, mobile phase composition, chromatographic column. Imperative changes have altered the ef fi ciency of the chromatographic separation; such changes include pH alteration of the mobile phase as well as alkyl sulfonate molarity changing. All robustness conditions showed no major effect on the chromatographic separation of the analyte except with the changes related to TFA and alkyl sulfonate ion pair reagents. Peak area RSD, asymmetry and No. of theoretical plates were 10,000, respectively. Results obtained using mobile phase after 6 months of storage have proven its stability and possibility of use. Gradient elution mode was utilized to elute cystatin c with a UV detection of 224 nm. Ace and Waters C8 (150 x 4.6 mm i.d., 5 μ m) as chromatographic columns were used.

9 citations


Journal ArticleDOI
TL;DR: In this article, a rapid and simple method for the separation and quantification of paromomycin sulfate and its impurities by HPLC coupled with evaporative light scattering detection (ELSD) was developed.
Abstract: A rapid and simple method for the separation and quanti fi cation of paromomycin sulfate and its impurities by HPLC coupled with evaporative light scattering detection (ELSD) was developed. The chromatographic conditions included the use of a GRACE Alltima C 18 column (250mm×4.6mm, 5 μ m) maintained at 30°C and a mobile phase of 0.2 M tri fl uoroacetic acid water–acetonitrile (96:4, v/v) at a fl ow rate of 0.6 mL/min. The in fl uence of gas pressure and temperature of the drift tube in the detector on the detection response was also investigated. A system suitability test to check the quality of the separation was speci fi ed. The method showed good repeatability, linearity and robustness. It also enabled the simultaneous determination of the inorganic counter ions (sulfates).

9 citations


Journal ArticleDOI
TL;DR: In order to perform a reliable pharmacokinetic study of cancer pain patients receiving morphine and oxycodone, an easy, rapid, sensitive and selective analytical method was proposed and validated.
Abstract: Morphine and oxycodone are widely used as analgesic drugs for cancer pain. Frequently, morphine and oxycodone are given alternately to avoid adverse drug reactions. Morphine is metabolized primarily into two glucuronide metabolites, morphine-3-glucuronide and morphine-6-glucuronide to be pharmacologically active. Morphine-3-glucuronide and morphine-6-glucuronide have neuroexcitatory action and analgesic activity, respectively. Oxymorphone, a metabolite of oxycodone, has an analgesic effect, however it is so small that it can be neglected when considering oxycodone. The pharmacological effects of these drugs and also their metabolites have been reported in experimental papers, but in humans, the relationships between these plasma concentrations and the clinical effects remain unclear. Also the necessity for simultaneous determination of both drugs has been suggested because opioid rotation is performed clinically. However, to date there is no study which has simultaneously determined these four drugs, and also achieved a high recovery. In this paper, in order to perform a reliable pharmacokinetic study of cancer pain patients receiving morphine and oxycodone, an easy, rapid, sensitive and selective analytical method was proposed and validated.

9 citations


Journal ArticleDOI
TL;DR: In this article, four simple, sensitive, and accurate spectrophotometric methods (A-D) have been developed for the determination of domperidone (I) and doxycycline (II) in bulk and in pharmaceutical formulations.
Abstract: Four simple, sensitive, and accurate spectrophotometric methods (A-D) have been developed for the determination of domperidone (I) and doxycycline (II) in bulk and in pharmaceutical formulations. The first two methods (A and B) are based on the formation of yellow ion-pair complexes between the examined drugs with bromocresol green (BCG) and methyl orange (MO) as chromophoric reagents in Britton-Robinson (B-R) universal buffer of pH 3.0 and 2.2, respectively. The formed complexes were extracted with chloroform and measured at 420 nm and 424 nm for I and II using BCG, respectively and 480 nm for the studied drugs using MO. The last two methods (C and D) are based on charge transfer complex formation between the studied drugs and tetracyanoethylene (TCNE); and 7,7,8,8-tetracyanoquinodimethane (TCNQ). Different variables affecting the reactions were studied and optimized. Under the optimum reaction conditions, linear relationships with good correlation coefficients (0.9992 - 0.9998) were found between the absorbance and the concentration of I in the range of 1.4-22.4μg mL −1 , whereas that for II in the range 1.4-25.5μg mL −1 . For more accurate analysis, Ringbom optimum concentration range was found to be between 3.0-21.5 and 3.0-23.5μg mL −1 , for I, and II, respectively. Sandell’s sensitivity, correlation coefficient, and limits of detection and quantification were calculated for each method. A Job’s plot of the absorbance versus the molar ratio of drug to each of formed complex under consideration indicated (1:1) ratio. No interference was observed from common pharmaceutical excipients and additives. Statistical comparison of the results with those obtained by the official method shows excellent agreement and indicates no significant difference in accuracy and precision.

8 citations


Journal ArticleDOI
TL;DR: A rapid and sensitive liquid chromatography/mass spectrometry (LC/MS) method was developed and validated and suitable for pharmacokinetic studies of saikosaponin a in rats.
Abstract: A rapid and sensitive liquid chromatography/mass spectrometry (LC/MS) method was developed and validated for the determination of saikosaponin a in rat plasma. Saikosaponin a was extracted by protein precipitation with acetonitrile and the chromatographic separation was performed on a C18 column. The total analytical run time was relatively short (5.5 min) and the limit of assay quantifi cation (LLOQ) was 10 ng mL-1 using 100 μL of rat plasma. Saikosaponin a and the internal standard (felodipine) were monitored in selected ion monitoring (SIM) mode at m/z 779.2 and 382.0, respectively. The standard curve was linear over a concentration range from 10 to 5000 ng mL-1 and the correlation coeffi cients were greater than 0.999. The recoveries of saikosaponin a from plasma were larger than 82% and RSD of inter-day and intra-day assay were below 10%. The method described in this report was sensitive and specifi c and suitable for pharmacokinetic studies of saikosaponin a in rats.

Journal ArticleDOI
TL;DR: It is found that use of the first derivative+vector normalization (FD+VN) removes the effects of packaging bottle and particle size in the NIR spectra.
Abstract: The wrapper composition, particle size and crystallinity of powder drugs all affect their NIR spectra. To remove these effects, one must apply proper spectral preprocessing methods and good algorithms before developing a NIR quantitative model. Though different spectral preprocessing methods possess different functions aimed at removing different effects, we have found that use of the first derivative+vector normalization (FD+VN) removes the effects of packaging bottle and particle size in the NIR spectra. The effect of crystallinity cannot be removed with spectral preprocessing methods, but it can be reduced by choosing a proper calibration set, choosing a specific principal component, and applying partial least squares fitting.

Journal ArticleDOI
TL;DR: The studies indicated that P. integerrima can be equated to ‘Kakadshringi’ and its indication for the treatment of diarrhoea and it may be due to their high phenolic and tannin content.
Abstract: T growing demand of crude drugs (raw materials and their products) by populations is forcing to develop standards for quality control and to evaluate the health climes. Much more studies in this aspect have been done on plant originated crude drugs/raw materials. Meager evaluation is available considering animal originated raw materials. Use of insect galls as medicine is not new but evaluation of such materials is unique. The ethnobotanical and Ayurvedic literature indicates that ‘Kakadshringi’ leaf galls are used for the treatment of diarrhoea. The leaf galls occurring on botanically three different plant species viz. Pistacia integrrima Stew. ex Brindis, Terminalia chebula Retz., and Garuga pinnata Roxb. are commerced in trade. These samples were standardized using pharmacognostic and phytochemical parameters to establish identification markers. To investigate the text clime, antidiarrheal activity was evaluated using animal modal. The result suggested that ethanol extract of P. integerrima and loperamide, a standard antidiarrheal drug showed significant reduction in fecal output in castor oil and magnesium sulphate induced diarrhoea and castor oil induced intraluminal fluid accumulation. Also it inhibited dose dependently (100-500 mg/kg) the intestinal propulsion of charcoal meal in normal and barium chloride induced changes in gastrointestinal tract. The ethanol extract of P. integerrima has antidiarrhoeal, antisecretory and antipropulsive activities and it may be due to their high phenolic and tannin content. Our studies indicated that P. integerrima can be equated to ‘Kakadshringi’ and its indication for the treatment of diarrhoea. Standardization and Preclinical Studies on ‘Kakadshringi’: Leaf Galls Used in Ayurvedic System of Medicine

Journal ArticleDOI
TL;DR: In the present study, HTS- compatible assays for COX-1,COX-2 and 5-LOX were developed for screening of compound libraries with the view to identify potential anti-inflammatory drug candidates.
Abstract: High-throughput screening (HTS) involves testing of compound libraries against validated drug targets using quantitative bioassays to identify 'hit' molecules that modulate the activity of target, which forms the starting point of a drug discovery effort. Eicosanoids formed via cyclooxygenase (COX) and lipoxygenase (LOX) pathways are major players in various inflammatory disorders. As the conventional non-steroidal anti-inflammatory drugs (NSAIDs) that inhibit both the constitutive (COX-1) and the inducible (COX-2) isoforms have gastric and renal side effects and the recently developed COX-2 selective anti-inflammatory drugs (COXIBs) have cardiac side effects, efforts are being made to develop more potent and safer anti- inflammatory drugs. Current assay methods for these enzymes, such as oxygraphic, radioisotopic, spectrophotometric etc. are not compatible for screening of large number of compounds as in drug discovery programs. In the present study, HTS- compatible assays for COX-1, COX-2 and 5-LOX were developed for screening of compound libraries with the view to identify potential anti-inflammatory drug candidates. A spectrophotometric assay involving co-oxidation of tetramethyl-p- phenylene diamine (TMPD) during the reduction of prostaglandin G 2 (PGG 2) to PGH 2 was adopted and standardized for screening of compounds against COX-1 and COX-2. Similarly, the HTS-compatible FOX (ferrous oxidation-xylenol orange) based spectrophotometric assay involving the formation of Fe 3+ /xylenol orange complex showing absorption in the visible range was developed for screening of compounds against 5-LOX.


Journal ArticleDOI
TL;DR: In this article, a new method using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF-MS) was developed for determination of quinocetone (QCT) and its major metabolites, 1-desoxyquinocetones (1-DQCT), 4-dioxinequinoxaline-2-carboxylic acid (MQCA) in swine liver.
Abstract: A new method using ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry (UPLC/ Q-TOF-MS) was developed for determination of quinocetone (QCT) and its major metabolites, 1–desoxyquinocetone (1– DQCT), 4–desoxyquinocetone (4–DQCT), 1,4–bisdesoxyquinocetone (DQCT) and methyl–3–quinoxaline–2–carboxylic acid (MQCA) in swine liver. Tissue samples were extracted by a two-step method. Firstly, all analytes except MQCA were extracted with ethyl acetate. Then a hydrochloric acid solution was added in the remained sediment for hydrolysis of combined MQCA. The MQCA in the acid extract was transferred to ethyl acetate by liquid-liquid extraction (LLE) approach. All the ethyl acetate extract were combined, evaporated, resolved in a phosphate buffer, and cleaned up using a Oasis MAX cartridges. The chromatographic separation of all the analytes was achieved in less than 5 min using UPLC. The identification and confirmation by accurate mass measurement and their different fragmentation pathways were performed on ESI-Q-TOF-MS (MS/MS). The quantitation was carried out in TOF mode using narrow window extracted ion chromatogram of each compound. In the range of 1-100 µg·kg–1, the calibration curve equations of MQCA, QCT, 4-DQCT, 1-DQCT and DQCT were y=0.7878x+10.49, y=4.656x+42.244, y=5.5825x+24.919, y=8.491x+21.195 and y=10.733x+160.72, respectively. And the relative coefficients of all calibration curves were higher than 0.98. The limit of detection and the limit of quantification were 1.4–4.8 µg·kg –1 and 4.6–15.9 µg·kg–1, respectively. The established method was validated for determination of incurred swine liver samples in an actual residue study.

Journal ArticleDOI
TL;DR: The laboratory has successfully demonstrated the ability to measure glucose, urea and other blood analytes in serum, whole blood and individual human volunteers and it is shown that correction for these non-analyte specific variances provides a clinically accurate and robust calibration algorithm that can be used for prospective prediction in human population.
Abstract: B applications of lasers and laser spectroscopy are changing the face of medicine as it is currently practiced. Spectroscopy is a promising means of extracting biochemical and morphological information from tissue that is relevant to disease progression and diagnosis. In particular, Raman spectroscopy is a powerful tool for non-invasive and real time diagnosis due to its exquisite molecular specificity and lack of sample preparation requirements. Raman spectroscopy, which measures the molecular vibrations of a sample, is currently being used to study atherosclerosis, measure blood analytes, and detect dysplasia and cancer in various tissues including the breast, cervix, prostate, and skin. In this talk, we present our results on quantitative biological spectroscopy for non-invasive blood analyte detection. Our work in this area is primarily motivated by the necessity for accurate and frequent measurement of blood glucose levels, which is most commonly achieved by withdrawal of blood. Given the inconvenience and invasiveness of this procedure, a non-invasive method would greatly benefit the increasing number of diabetics. Our laboratory has successfully demonstrated the ability to measure glucose, urea and other blood analytes in serum, whole blood and individual human volunteers. In addition, we present our results for turbidity correction and suppression of tissue autofluorescence in biological Raman spectroscopy. We show that correction for these non-analyte specific variances provides a clinically accurate and robust calibration algorithm that can be used for prospective prediction in human population. Finally, we discuss our plans for miniaturization of the device for point of care and commercial applications. Raman Spectroscopy: An Emerging Tool for Clinical Diagnostics

Journal ArticleDOI
TL;DR: In the metabolic approach, permeation rate is enhanced by delaying this natural recovery processes by application of chemicals/drugs that interfere with the skin metabolism, however, to use this strategy, one has to have a clear understanding of the constituents of the skin as well as the mechanism of Skin homeostasis.
Abstract: T enhance the skin permeability of a drug, the barrier function of the skin must be overcome at least temporarily. The barrier function of stratum corneum –the rate limiting membrane for skin permeation, depends upon the quality and quantity of its constituent lipids and a decrease in their concentration affects its barrier properties. In general, barrier disruption is followed by quick recovery responses. In the metabolic approach, permeation rate is enhanced by delaying this natural recovery processes by application of chemicals/drugs that interfere with the skin metabolism. However, to use this strategy, one has to have a clear understanding of the constituents of the skin as well as the mechanism of Skin homeostasis. The present article discusses some important aspects related to it. 1) the liquid crystalline nature of stratum corneum (the cholesterol and ceramides) 2) the biophysical aspects of the barrier lipids, 3) the sequence of events at stratum granulosum-stratum corneum interface, 4) role of different enzymes/ drugs (HMGCoA Reductase inhibitors) that interfere with barrier recovery and thereby enhance permeation rate of drugs. Important research on this aspect is also analyzed along with the advantages and limitations of the strategy. Enhancement of Skin Permeation: the Metabolic Approach