Establishment of a Standard Assay Method for Human Thrombomodulin and Determination of the Activity of the Japanese Reference Standard

Biologicals ◽  
2002 ◽  
Vol 30 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Shingo Niimi ◽  
Tadashi Oshizawa ◽  
Masaaki Naotsuka ◽  
Sumiaki Ohba ◽  
Akira Yokozawa ◽  
...  
Keyword(s):  
Assay Method ◽  
Reference Standard ◽  
Standard Assay

Ethopabate in Feeds

1965 ◽  
Vol 48 (2) ◽  
pp. 280-284
Author(s):  
C R Szalkowski
Keyword(s):  
Room Temperature ◽  
Sodium Carbonate Solution ◽  
Collaborative Study ◽  
Chloroform Extract ◽  
Assay Method ◽  
Reference Standard ◽  
Free Amine ◽  
Commercial Poultry ◽  
Colored Compound

Abstract A collaborative study was completed on a method for the determination of ethopabate. Ethopabate is extracted from the feed with 50% methanol at room temperature, and separated from amines by chloroform extraction. The chloroform extract is washed with sodium carbonate solution to remove interfering drugs, if present. Chloroform is removed by evaporation, and the ethopabate residue is hydrolyzed with HCI to the free amine, which is diazotized and coupled. The colored compound is extracted and measured at 555 mμ against pure reference standard ethopabate. Unmedicated commercial poultry feeds showed an apparent ethopabate content of 0.2–0.5 ppm. Recoveries from these same feeds after medication with ethopabate ranged from 96 to 105%. This assay method is suitable for determining ethopabate down to 2 ppm and is recommended for adoption as official, first action, for all levels of ethopabate.

Development of Validated Stability Indicating HPTLC Method for Assay of Ozagrel and its Pharmaceutical Formulations

2018 ◽  
pp. 36-48 ◽  
Author(s):  
Vishal N Kushare ◽  
Sachin S Kushare
Keyword(s):  
High Performance ◽  
Linear Regression Analysis ◽  
Pharmaceutical Formulations ◽  
Base Hydrolysis ◽  
Assay Method ◽  
Related Substance ◽  
Stability Indicating ◽  
Regular Production ◽  
Hptlc Method

The present paper describes stability indicating high-performance thin-layer chromatography (HPTLC) assay method for Ozagrel in bulk drugs. The method employed TLC aluminium plates precoated with silica gel 60F-254 as the stationary phase. The solvent system consisted of toluene: methanol: triethylamine (6.5: 4.0: 0.1 v/v/v). The system was found to give compact spot for Ozagrel (Rf value of 0.40 ± 0.010). Densitometric analysis of Ozagrel was carried out in the absorbance mode at 280 nm. The linear regression analysis data for the calibration plots showed good linear relationship with r2 = 0.999 with respect to peak area in the concentration range 30 - 120 ng/spot. The developed HPTLC method was validated with respect to accuracy, precision, recovery and robustness. Also to determine related substance and assay determination of Ozagrel that can be used to evaluate the quality of regular production samples. The developed method can also be conveniently used for the assay determination of Ozagrel in pharmaceutical formulations. The limits of detection and quantitation were 4.069 and 12.332 ng/spot, respectively by height. Ozagrel was subjected to acid and alkali hydrolysis, oxidation, photochemical and thermal degradation. The drug undergoes degradation under acidic, basic, oxidation and heat conditions. This indicates that the drug is susceptible to acid, base hydrolysis, oxidation and heat. Statistical analysis proves that the method is repeatable, selective and accurate for the estimation of said drug. The proposed developed HPTLC method can be applied for identification and quantitative determination of Ozagrel in bulk drug and tablet formulation.

Stability Indicating Liquid Chromatographic Method for the Determination of Fenofibrate and its Application to Kinetic Studies

2013 ◽  
Vol 5 (4) ◽  
pp. 1866-1874
Author(s):  
K. Srinivasa Rao ◽  
Keshar N K ◽  
N Jena ◽  
M.E.B Rao ◽  
A K Patnaik
Keyword(s):  
Degradation Products ◽  
Kinetic Studies ◽  
Pharmaceutical Formulations ◽  
Assay Method ◽  
Pharmaceutical Dosage Form ◽  
Stability Indicating ◽  
Zero Order Kinetics ◽  
Relative Standard ◽  
Liquid Chromatographic

A stability-indicating LC assay method was developed for the quantitative determination of fenofibrate (FFB) in pharmaceutical dosage form in the presence of its degradation products and kinetic determinations were evaluated in acidic, alkaline and peroxide degradation conditions. Chromatographic separation was achieved by use of Zorbax C18 column (250 × 4.0 mm, 5 μm). The mobile phase was established by mixing phosphate buffer (pH adjusted 3 with phosphoric acid) and acetonitrile (30:70 v/v). FFB degraded in acidic, alkaline and hydrogen peroxide conditions, while it was more stable in thermal and photolytic conditions. The described method was linear over a range of 1.0-500 μg/ml for determination of FFB (r= 0.9999). The precision was demonstrated by relative standard deviation (RSD) of intra-day (RSD= 0.56– 0.91) and inter-day studies (RSD= 1.47). The mean recovery was found to be 100.01%. The acid and alkaline degradations of FFB in 1M HCl and 1M NaOH solutions showed an apparent zero-order kinetics with rate constants 0.0736 and 0.0698  min−1 respectively and the peroxide degradation with 5% H2O2 demonstrated an apparent first-order kinetics with rate constant k = 0.0202 per min. The t1/2, t90   values are also determined for all the kinetic studies. The developed method was found to be simple, specific, robust, linear, precise, and accurate for the determination of FFB in pharmaceutical formulations.  

Development and Validation of a New Method for the Determination of Anti-hepatitis C Agent Simeprevir in Human Plasma using HPLC with Fluorescence Detection

2020 ◽  
Vol 16 (4) ◽  
pp. 428-435
Author(s):  
Ahmed F.A. Youssef ◽  
Yousry M. Issa ◽  
Kareem M. Nabil
Keyword(s):  
Hepatitis C ◽  
Human Plasma ◽  
Fluorescence Detection ◽  
Internal Standard ◽  
Protein Precipitation ◽  
Assay Method ◽  
Fluorescence Detector ◽  
Limit Of Quantification ◽  
Relative Standard

Background: Simeprevir is one of the recently discovered drugs for treating hepatitis C which is one of the major diseases across the globe. Objective: The present study involves the development of a new and unique High-Performance Liquid Chromatography (HPLC) method using fluorescence detection for the determination of simeprevir (SIM) in human plasma. Methods: Two methods of extractions were tested, protein precipitation using acetonitrile and liquidliquid extraction. A 25 mM dipotassium hydrogen orthophosphate (pH 7.0)/ACN (50/50; v/v), was used as mobile phase and C18 reversed phase column as the stationary phase. The chromatographic conditions were optimized and the concentration of simeprevir was determined by using the fluorescence detector. Cyclobenzaprine was used as an internal standard. Results: Recovery of the assay method based on protein precipitation was up to 100%. Intra-day and inter-day accuracies range from 92.30 to 107.80%, with Relative Standard Deviation (RSD) range 1.65-8.02%. The present method was successfully applied to a pharmacokinetic study where SIM was administered as a single dose of 150 mg SIM/capsule (Olysio®) to healthy individuals. Conclusion: This method exhibits high sensitivity with a low limit of quantification 10 ng mL-1, good selectivity using fluorescence detection, wide linear application range 10-3000 ng mL-1, good recovery and highly precise and validation results. The developed method can be applied in routine analysis for real samples.

Novel Determination of Anti-Hypertensive Combination; Benidipine Hydrochloride and Nebivolol Hydrochloride by High Performance Chromatographic Method

2021 ◽  
pp. 5433-5438
Author(s):  
V.L.N. Balaji Gupta Tiruveedhi ◽  
Venkateswara Rao Battula ◽  
Kishore Babu Bonige ◽  
Tejeswarudu B.
Keyword(s):  
High Performance ◽  
Degradation Products ◽  
Research Work ◽  
Hplc Method ◽  
Assay Method ◽  
Injection Quantity ◽  
Relative Standard ◽  
Nebivolol Hydrochloride ◽  
Concentration Series

This research work was designed to establish and validate a novel stability indicating RP-HPLC method for the combined determination of Benidipine hydrochloride (BHE) and Nebivolol hydrochloride (NHE) in bulk and tablets, dependent on ICH guidelines.The assay method to analyse BHE and NHE was optimized with isocratic elution using acetonitrile: 0.1M acetate buffer (45:55, pH 5.1), Lichrospher ODS RP-18 column and flow pace of 1 ml/min. Total time for single run was 14 min. The injection quantity was 20μl, and was detected at 249nm. The method was verified on a concentration series of 1.25-10μg/ml (NHE) and 1.0-10μg/ml (BHE) for precision, accuracy and linearity. The LOD values were 0.059µg/ml and 0.028µg/ml for NHE and BHE, respectively. The LOQ values were 0.196µg/ml for NHE and 0.094µg/ml for BHE. The recovery percentages were 98.60-100.11% (BHE) and 98.94-101.50% (NHE) with relative standard deviation 0.250-0.694% (BHE) and 0.183-0.400% (NHE). The method was also observed to be efficient, and was sufficiently specific to measure BHE and NHE in the presence of stress-produced degradation products.

Immunofluorescent Staining of Mouse Pancreas for Islet Cell Mass Analysis v1

2021 ◽  
Author(s):  
Islet and Pancreas Analysis Core
Keyword(s):  
Quantitative Determination ◽  
Islet Cell ◽  
Cell Mass ◽  
Immunofluorescent Staining ◽  
Assay Method ◽  
Mass Analysis ◽  
Mouse Pancreas ◽  
Cell Composition ◽  
Diabetes Center

This SOP defines the assay method used by the Vanderbilt Diabetes Center Islet and Pancreas Analysis (IPA) Core for quantitative determination of the islet cell composition and islet cell mass of mouse pancreas by immunofluorescent staining.

scholarly journals Determination of Organosulfides from Onion Oil

Foods ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 884 ◽  
Author(s):  
Maranda S. Cantrell ◽  
Jared T. Seale ◽  
Sergio A. Arispe ◽  
Owen M. McDougal
Keyword(s):  
Diethyl Ether ◽  
Steam Distillation ◽  
Extraction Efficiency ◽  
Agricultural Products ◽  
Gas Chromatography Mass Spectrometry ◽  
Diallyl Disulfide ◽  
Reference Standard ◽  
Internal Reference ◽  
Internal Reference Standard

Qualitative and semi-quantitative analysis of organosulfides extracted from oil obtained by steam distillation of yellow onions was performed by gas chromatography-mass spectrometry (GC-MS). The extraction efficiency of organosulfides from onion oil was evaluated across four solvents: dichloromethane; diethyl ether; n-pentane; and hexanes. Analysis of solvent extracted organosulfides by GC-MS provided qualitative results that support the use of dichloromethane over other solvents based on identification of 27 organosulfides from the dichloromethane extract as compared to 10 from diethyl ether; 19 from n-pentane; and 17 from hexanes. Semi-quantitative evaluation of organosulfides present in the dichloromethane extract was performed using diallyl disulfide as the internal reference standard. Three organosulfides were detected in the extract at ≥5 mg/kg; 18 organosulfides between 3–5 mg/kg; and six organosulfides at <3 mg/kg. The E/Z isomers of 1-propenyl propyl trisulfide were among the most prevalent components extracted from the onion oil across all solvents; and 3,6-diethyl-1,2,4,5-tetrathiane was among the most abundant organosulfides in all solvents except hexanes. The method described here for the extraction of organosulfides from steam distilled onion oil surveys common solvents to arrive at a qualitative and semi-quantitative method of analysis for agricultural products involving onions; onion oil; and secondary metabolites of Allium spp.

scholarly journals RAPID ANALYTICAL METHOD FOR ASSAY DETERMINATION FOR PROCHLORPERAZINE EDISYLATE DRUG SUBSTANCES BY ULTRA PERFORMANCE LIQUID CHROMATOGRAPHY

2017 ◽  
Vol 9 (4) ◽  
pp. 118 ◽  
Author(s):  
Kishorkumar L. Mule
Keyword(s):  
Liquid Chromatography ◽  
Trifluoroacetic Acid ◽  
Analytical Method ◽  
Mobile Phase ◽  
Ultra Performance Liquid Chromatography ◽  
Drug Substance ◽  
Assay Method ◽  
Column Temperature ◽  
Drug Substances

Objective: To develop and validate new, simple and rapid assay method for Prochlorperazine edisylate drug substance by UPLC as per ICH guidelines.Methods: Ultra performance liquid chromatographic method was developed, optimized and validated on Acquity UPLC by using Acquity BDH300 C4 (100 x 2.1 mm) 1.7µ column. 3.85g ammonium acetate in 1000 ml of water add 0.5 ml trifluoroacetic acid and 1 ml triethylamine (Mobile phase A): 0.5 ml trifluoroacetic acid in 1000 ml acetonitrile mobile phase (Mobile phase B) with gradient program. Detector wavelength 254 nm and column temperature 30 °C.Results: Linearity study was carried out for prochlorperazine edisylate, linearity was calculated from 80 % level to 120% with respect to specification level. The correlation coefficient (r) = 0.999 was proved that the method is robust. The resolution between known impurities and Prochlorperazine edisylate found more than 2.5, it was evident from specificity test that Prochlorperazine edisylate peak are well separated from its related impurities, hence the method is specific. Prochlorperazine edisylate sample solution and mobile phase were found to be stable for at least 3 d.Conclusion: A new, simple and rapid method has been developed and validated for assay determination of prochlorperazine edisylate in drug substance by Ultra Performance Liquid Chromatography (UPLC). The analytical method was developed and validated as per ICH guidelines. The developed method can be used for the fast assay determination of prochlorperazine edisylate drug substances in research laboratories and in the pharmaceutical industry. 

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