scholarly journals SubcriticalWater Extraction and Determination of Nifedipine in Pharmaceutical Formulations

2006 ◽  
Vol 89 (2) ◽  
pp. 365-368 ◽  
Author(s):  
Pablo Richter ◽  
Maria Ines Toral ◽  
Carla Toledo
Keyword(s):  
Subcritical Water ◽  
Pharmaceutical Formulations ◽  
Hot Water ◽  
Content Uniformity ◽  
Extraction Temperature ◽  
Subcritical Water Extraction ◽  
Quantitative Extraction ◽  
Relative Standard ◽  
Dynamic Extraction

Abstract A rapid and simple continuous method for the extraction of nifedipine from tablets was developed by using pressurized hot water at 150C. This is the first time that subcritical water was applied to the extraction of low-polarity compounds in pharmaceutical analysis. The method is based on the increment in solubility of nifedipine in subcritical water. Extraction temperature and static and dynamic extraction time were optimized in order to reach quantitative extraction of the drug from the tablets. After extraction, the drug was determined by spectrophotometry by measuring absorbance at 338 nm. Accuracy and precision of themethodwere determined by analysis of 10 synthetic samples of pharmaceutical formulations preparedwith common tablet excipients. Recoverywas found to be 99.2with a relative standard deviation of 1.9, which indicates that the excipients of the formulation do not interfere in the determination. The method was applied to the determination of the drug content uniformity in tablets.

scholarly journals Optimization of Subcritical Water Extraction of Polysaccharides from Inonotus Obliquus and their Antioxidant Activities

2017 ◽  
Vol 9 (3) ◽  
pp. 38 ◽  
Author(s):  
Xi Yuan ◽  
Ling Li ◽  
Hongyi Sun ◽  
Shuang Sun ◽  
Zhenya Zhang
Keyword(s):  
Subcritical Water ◽  
Antioxidant Activities ◽  
Hot Water ◽  
Water Extraction ◽  
Extraction Temperature ◽  
Subcritical Water Extraction ◽  
Inonotus Obliquus ◽  
Solid Ratio ◽  
Ft Ir

Subcritical water extraction (SWE) of Inonotus Obliquus polysaccharides (IOP) was investigated using response surface methodology (RSM) with a design by Box–Behnken design (BBD). Results showed that the optimum SWE conditions for IOP production were as follows: extraction temperature 194°C, residence time 5.36 min and liquid-solid ratio 53 mL/g, yielding 168.80 ± 0.59 mg/g of IOP, which was in close agreement with the values predicted by the mathematical model. FT-IR spectra of the polysaccharides extracted by SWE and hot water extraction (HWE) were compared as well. Moreover, in vitro antioxidant assays revealed that SWE-IOP exhibited stronger scavenging activity that HWE-IOP. This investigation suggests that polysaccharides of Inonotus Obliquus extracted by SWE could be further developed as a potential antioxidant resource for dietary supplements of functional food.

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.  

RP-HPLC METHOD DEVELOPMENT FOR THE ASSAY OF AMPHOTERICIN B

INDIAN DRUGS ◽  
2014 ◽  
Vol 51 (02) ◽  
pp. 16-20
Author(s):  
L Mohankrishna ◽  
◽  
P. J. Reddy ◽  
B. P Reddy. ◽  
P. Navya
Keyword(s):  
Amphotericin B ◽  
Mobile Phase ◽  
Method Development ◽  
Pharmaceutical Formulations ◽  
Hplc Method ◽  
Ich Guidelines ◽  
Relative Standard ◽  
Phase Combination ◽  
Hplc Method Development

A sensitive and precise HPLC procedure has been developed for the assay of amphotericin B in bulk samples and pharmaceutical formulations by using a C18 column [Kromosil, C18, (5 µm, 4.6mm x 250 mm; Make. Waters)], and mobile phase combination is 1% formic acid in water and acetonitrile in ratio of 45:55 V/V. The procedure has been validated as per the ICH guidelines. The λmax of detection was fixed at 407 nm, so that there was less interference from mobile phase with highest sensitivity according to UV analysis. Calibration plots were linear in the range of 10-100 µg/mL and the LOD and LOQ were 0.02 µg/mL and 0.06 µg/mL respectively. The high recovery and low relative standard deviation confirm the suitability of the method for routine quality control determination of amphotericin B in different formulations.

scholarly journals Spectrophotometric flow injection procedure to indirect determination of paracetamol in pharmaceutical formulations using o-tolidine as reagent

2018 ◽  
Vol 33 (2) ◽  
pp. 47
Author(s):  
Orlando Fatibello-Filho ◽  
Heberth Juliano Vieira
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Flow Injection ◽  
Pharmaceutical Formulations ◽  
Injection Method ◽  
Indirect Determination ◽  
Analytical Curve ◽  
Relative Standard ◽  
Injection Procedure

A spectrophotometric flow injection method for the determination of paracetamol in pharmaceutical formulations is proposed. The procedure was based on the oxidation of paracetamol by sodium hypochloride and the determination of the excess of this oxidant using o-tolidine dichloride as chromogenic reagent at 430 nm. The analytical curve was linear in the paracetamol concentration range from 8.50 x 10-6 to 2.51 x 10-4 mol L-1 with a detection limit of 5.0 x 10-6 mol L-1. The relative standard deviation was smaller than 1.2% for 1.20 x 10-4 mol L-1 paracetamol solution (n = 10). The results obtained for paracetamol in pharmaceutical formulations using the proposed flow injection method and those obtained using a USP Pharmacopoeia method are in agreement at the 95% confidence level.

scholarly journals A sensitive spectrophotometric determination of tadalafil in pharmaceutical preparations and industrial wastewater samples

2013 ◽  
Vol 10 (3) ◽  
pp. 1005-1013 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Standard Deviation ◽  
Industrial Wastewater ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Average Recovery ◽  
Relative Standard ◽  
Wastewater Samples ◽  
Sensitive Spectrophotometric Method

A simple, accurate, precise, rapid, economical and a high sensitive spectrophotometric method has been developed for the determination of tadalafil in pharmaceutical preparations and industrial wastewater samples, which shows a maximum absorbance at 204 nm in 1:1 ethanol-water. Beer's law was obeyed in the range of 1-7?g/ mL ,with molar absorptivity and Sandell ? s sensitivity of 0.783x105l/mol.cm and 4.97 ng/cm2respectively, relative standard deviation of the method was less than 1.7%, and accuracy (average recovery %) was 100 ± 0. 13. The limits of detection and quantitation are 0.18 and 0.54 µg .ml-1, respectively. The method was successfully applied to the determination of tadalafil in some pharmaceutical formulations (tablets) and industrial wastewater samples. The proposed method was validated by sensitivity and precision which proves suitability for the routine analysis of tadalafil in true samples.

Determination of atmospheric particle-bound polycyclic aromatic hydrocarbons using subcritical water extraction coupled with membrane microextraction

2019 ◽  
Vol 1606 ◽  
pp. 460381 ◽  
Author(s):  
Carlos Ramos-Contreras ◽  
Estefanía Concha-Graña ◽  
Purificación López-Mahía ◽  
Francisco Molina-Pérez ◽  
Soledad Muniategui-Lorenzo
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Subcritical Water ◽  
Water Extraction ◽  
Subcritical Water Extraction ◽  
Atmospheric Particle ◽  
Polycyclic Aromatic

scholarly journals DEVELOPMENT AND VALIDATION OF ULTRAVIOLET-SPECTROPHOTOMETRIC METHOD FOR DETERMINATION OF FEBUXOSTAT FOR CONDUCTING IN-VITRO QUALITY CONTROL TESTS IN BULK AND PHARMACEUTICAL DOSAGE FORMS

2018 ◽  
Vol 11 (9) ◽  
pp. 115
Author(s):  
Jaspreet Kaur ◽  
Daljit Kaur ◽  
Sukhmeet Singh
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Formulations ◽  
Dosage Forms ◽  
Pharmaceutical Dosage Forms ◽  
Relative Standard ◽  
Limit Of Quantitation ◽  
Development And Validation

Objective: A simple, accurate, and selective ultraviolet-spectrophotometric method has been developed for the estimation of febuxostat in the bulk and pharmaceutical dosage forms.Method: The method was developed and validated according to International Conference on Harmonization (ICH Q2 R1) guidelines. The developed method was validated statistically with respect to linearity, range, precision, accuracy, ruggedness, limit of detection (LOD), limit of quantitation (LOQ), and recovery. Specificity of the method was demonstrated by applying different stressed conditions to drug samples such as acid hydrolysis, alkaline hydrolysis, oxidative, photolytic, and thermal degradation.Results: The study was conducted using phosphate buffer pH 6.8 and λmax was found to be 312 nm. Standard plot having a concentration range of 1–10 μg/ml showed a good linear relationship with R2=0.999. The LOD and LOQ were found to be 0.118 μg/ml and 0.595 μg/ml, respectively. Recovery and percentage relative standard deviations were found to be 100.157±0.332% and <2%, respectively.Conclusion: Proposed method was successfully applicable to the pharmaceutical formulations containing febuxostat. Thus, the developed method is found to be simple, sensitive, accurate, precise, reproducible, and economical for the determination of febuxostat in pharmaceutical dosage forms.

Optimization of an Aqueous Two-Phase System for the Determination of Trace Ethyl Carbamate in Red Wine

2019 ◽  
Vol 82 (8) ◽  
pp. 1377-1383 ◽  
Author(s):  
LIJUAN MA ◽  
WENZHE TONG ◽  
LIPING DU ◽  
SHIYONG HUANG ◽  
JINYAN WEI ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Red Wine ◽  
Ethyl Carbamate ◽  
Phase System ◽  
Extraction Temperature ◽  
Two Phase ◽  
Aqueous Two Phase System ◽  
Relative Standard ◽  
Standard Deviations

ABSTRACT In this study, a novel method using gas chromatography–mass spectrometry coupled with ethanol and K2HPO4 aqueous two-phase system (ATPS) was established for the quantitative determination of trace ethyl carbamate (EC) in red wine. The parameters that influence EC extraction in an aqueous two-phase system, including extraction temperature, time, pH, and ethanol concentration, were optimized. Method validation results indicated that the regression coefficient of the proposed method was 0.9979 in the linear range of 10 to 100 μg/L, and the limits of detection and quantification were 2.8 and 9.2 μg/L, respectively. Four red wine samples made from different grape varieties were processed by the proposed method for the repeatability verification, and EC concentrations were between 15.8 and 37.3 μg/L, with the relative standard deviations ranging from 3.5 to 6.6%. Results of the precision assay showed the average recovery of EC in red wine at 95.4 to 107.1%, with the relative standard deviations ranging from 1.4 to 6.2%. This method proved to be simple and reliable for quantitative determination of trace EC in red wine and would give guidance for quality monitoring of various red wines in the production process.

scholarly journals Enantiomeric Separation of Colchicine and Lacosamide by Nano-LC. Quantitative Analysis in Pharmaceutical Formulations

Separations ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 55
Author(s):  
Natalia Casado ◽  
Zhengjin Jiang ◽  
María Ángeles García ◽  
María Luisa Marina
Keyword(s):  
Chiral Stationary Phase ◽  
Capillary Column ◽  
Pharmaceutical Formulations ◽  
Enantiomeric Separation ◽  
Chiral Drugs ◽  
Analytical Methodology ◽  
Ich Guidelines ◽  
Relative Standard ◽  
Nano Liquid Chromatography

A chiral analytical methodology was developed by nano-liquid chromatography (nano-LC) enabling the enantiomeric separation of two chiral drugs, lacosamide (novel antiepileptic drug) and colchicine (antiuremic drug), commercialized as pure enantiomers. A capillary column lab-packed with an amylose tris(3,5-dimethylphenylcarbamate) chiral stationary phase was used in a lab-assembled nano-LC system. Lacosamide and colchicine enantiomers were separated in less than 8.0 and 9.0 min, respectively, with resolution values of 1.6 and 2.3, using 20 nL of sample and 1.8 µL of mobile phase per analysis. The analytical characteristics of the proposed methodology were evaluated according to the International Council for Harmonisation (ICH) guidelines, showing good analytical performance with good recoveries (97–98% and 100–103%) and precision values (relative standard deviation (RSD) <10.5 and <3.0%) for lacosamide and colchicine enantiomers, respectively. LODs were 1.7 and 2.0 µg/mL for (S)- and (R)-lacosamide, respectively, and 1.0 µg/mL for both colchicine enantiomers. Additionally, the developed methodology enabled to detect a 0.1% of the enantiomeric impurities, fulfilling the ICH regulation requirements. The method was applied to the determination of lacosamide and colchicine enantiomers in different pharmaceutical formulations to ensure their quality control. The content of the enantiomeric impurities was below a 0.1% and the amount of (R)-lacosamide and (S)-colchicine agreed with their labeled contents.

First-Derivative Spectroscopic Determination of Acetaminophen and Sodium Salicylate in Tablets

1983 ◽  
Vol 66 (6) ◽  
pp. 1450-1454
Author(s):  
David Y Tobias
Keyword(s):  
Sodium Salicylate ◽  
Spectroscopic Method ◽  
Content Uniformity ◽  
First Derivative ◽  
Relative Standard ◽  
Chromatographic Procedure ◽  
Liquid Chromatographic ◽  
Spectral Responses ◽  
Selection Of

Abstract A first-derivative spectroscopic method for the simultaneous determination of acetaminophen and sodium salicylate in tablets was developed. Solutions of this drug combination in acidic ethanol were analyzed using their respective spectral responses at 258.5 and 317.0 nm. The method, which can be used for tablet composite assay and content uniformity analysis, is linear for acetaminophen concentrations ranging from 0.0 to 21.6 μ/mL, and for sodium salicylate concentrations ranging from 0.0 to 36.0 μ/mL. Relative standard deviations for the assay of both drugs in commercial tablets were &lt;2%, and recoveries of acetaminophen and sodium salicylate from spiked samples were 99.7 and 100.1%, respectively. The results obtained by first-derivative spectroscopy were in agreement with the results of a liquid chromatographic procedure for acetaminophen and a fluorometric method for sodium salicylate. The technique used for the selection of wavelengths for analysis is also described.

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