scholarly journals Polymeric Matrix Membrane Sensors for Stability-Indicating Potentiometric Determination of Oxybutynin Hydrochloride and Flavoxate Hydrochloride Urogenital System Drugs

2008 ◽  
Vol 91 (6) ◽  
pp. 1318-1330 ◽  
Author(s):  
Mohamed Heba ◽  
Nesrin Ramadan ◽  
Moustafa El-Laithy
Keyword(s):  
Degradation Products ◽  
Pharmaceutical Formulations ◽  
Official Method ◽  
Urogenital System ◽  
Electroactive Materials ◽  
Significant Difference ◽  
Ph Range ◽  
Oxybutynin Hydrochloride ◽  
Flavoxate Hydrochloride

Abstract Four polyvinyl chloride (PVC) matrix membrane electrodes responsive to 2 drugs affecting the urogenital systemoxybutynin hydrochloride (OX) and flavoxate hydrochloride (FX)were developed, described, and characterized. A precipitation-based technique with tungstophosphate (TP) and ammonium reineckate (R) anions as electroactive materials in a PVC matrix with an OX cation was used for electrode 1 and 2 fabrication, respectively. Electrode 3 and 4 fabrication was based on use of the precipitation technique of FX cation with tetrakis (4-chlorophenyl) borate and R anions as electroactive materials. Fast and stable Nernstian responses in the range 1 1021 106 M for the 2 drugs over the pH range 58 revealed the performance characteristics of these electrodes, which were evaluated according to International Union of Pure and Applied Chemistry recommendations. The method was applied to FX and OX in their pharmaceutical formulations and in human plasma samples. The 4 proposed sensors were found to be specific for the drugs in the presence of up to 60 of their degradation products. Validation of the method according to the quality assurance standards showed suitability of the proposed electrodes for use in the quality control assessment of these drugs. The recoveries for determination of the drugs by the 4 proposed selective electrodes were 99.5 0.5, 100.0 0.4, 99.9 0.4, and 100.1 0.4 for sensors 14, respectively. Statistical comparison between the results obtained by this method and the official method of the drugs was done, and no significant difference found.

scholarly journals Membrane Electrodes for Determination of Some -Blocker Drugs

2007 ◽  
Vol 90 (4) ◽  
pp. 987-994 ◽  
Author(s):  
Nesrin K Ramadan ◽  
Hala E Zaazaa
Keyword(s):  
Pharmaceutical Formulations ◽  
Official Method ◽  
Membrane Electrodes ◽  
Timolol Maleate ◽  
Electroactive Material ◽  
Poly Vinyl Chloride ◽  
Significant Difference ◽  
Ph Range ◽  
Quality Assurance Standards

Abstract Five poly(vinyl chloride) (PVC) matrix membrane electrodes responsive to the -blockers atenolol (AT), bisoprolol fumarate (BI), timolol maleate (TI), and levobunolol HCl (LV) were developed and characterized. A precipitation-based technique with ammonium reineckate anion as an electroactive material in PVC matrix with AT, BI, TI, and LV cations was used for fabrication of Electrodes 14, respectively. Electrode 5 fabrication was based on precipitation of LV cation with tungstophosphate anion as an electroactive material. Fast and stable Nernstian responses at 1 1021 107 M for different -blockers over the pH range of 28 were found for these electrodes, which were evaluated according to International Union of Pure and Applied Chemistry recommendations. The method was successively applied for the determination of -blockers in their pharmaceutical formulations. Validation of the method according to quality assurance standards showed the suitability of the proposed electrodes for use in the quality control assessment of these drugs. The recoveries for the determination of the -blocker drugs by the 5 proposed selective electrodes were 100.1 0.7, 99.9 0.8, 100.0 1.1, 100.5 1.1, and 100.6 0.7% for Sensors 15, respectively. Statistical comparison between the results obtained by this method and the official method of the drugs was performed and no significant difference was found.

scholarly journals Use of a diazocoupling reaction for sensitive and selective spectrophotometeric determination of furosemide in spiked human urine and pharmaceuticals

2010 ◽  
Vol 64 (4) ◽  
Author(s):  
Kalsang Tharpa ◽  
Kanakapura Basavaiah ◽  
Kanakapura Vinay
Keyword(s):  
Correlation Coefficient ◽  
Human Urine ◽  
Pharmaceutical Formulations ◽  
Chromotropic Acid ◽  
Disulfonic Acid ◽  
Official Method ◽  
Spectrophotometric Methods ◽  
Significant Difference ◽  
Spiked Human Urine

AbstractTwo simple, sensitive, and selective spectrophotometric methods for the determination of 5-(aminosulfonyl)-4-chloro-2-((2-furanylmethyl)amino)benzoic acid (furosemide, FUR) are described. The methods are based on acid hydrolysis of FUR to free primary aromatic amine and diazotization followed by coupling with N-1-napthylethylene diamine (NEDA) (method A) or 4,5-dihydroxynaphthalene-2,7-disulfonic acid (chromotropic acid, CTA) (method B). The colored reaction product can be measured spectrophotometrically at 520 nm (method A) or 500 nm (method B). Beer’s law is obeyed over the ranges of 1.75–21.0 μg mL−1 and 2.5–30.0 μg mL−1, for method A and method B, respectively. Apparent molar absorptivities and Sandell’s sensitivities (in L mol−1 cm−1 and μg cm−2 per 0.001 absorbance unit, respectively) were 1.34 × 104 and 0.0253 using NEDA as the coupling agent, and 8.5 × 103 and 0.0389 using CTA for the same purpose. Analysis of solutions containing seven different concentrations of FUR gave a correlation coefficient of 0.9979 using NEDA and 0.9984 using CTA, while the slope and the correlation coefficient of the regression equation were calculated. The reaction stoichiometry in both methods was evaluated by the limiting logarithmic method and was found to be 1: 1 (diazotized FUR: NEDA or diazotized FUR: CTA). The methods were successfully applied to the determination of FUR in spiked human urine and in pharmaceutical formulations. The recovery of FUR from spiked urine was satisfactory resulting in the values of (109.4 ± 4.37) % using NEDA and (113.0 ± 4.74) % using CTA. Results of the analysis of pharmaceuticals demonstrated that the proposed procedures are at least as accurate and precise as the official method while a statistical analysis indicated that there was no significant difference between the results obtained by the proposed methods and those of the official method.

Validated Stability-Indicating Spectrophotometric Methods for the Determination of Cefixime Trihydrate in the Presence of its Acid and Alkali Degradation Products

2015 ◽  
Vol 98 (1) ◽  
pp. 35-45 ◽  
Author(s):  
Nadia M Mostafa ◽  
Laila Abdel-Fattah ◽  
Soheir A Weshahy ◽  
Nagiba Y Hassan ◽  
Shereen A Boltia
Keyword(s):  
Degradation Product ◽  
Degradation Products ◽  
Pharmaceutical Formulations ◽  
Regression Equations ◽  
Acid Degradation ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
Accuracy And Precision ◽  
Significant Difference

Abstract Five simple, accurate, precise, and economical spectrophotometric methods have been developed for thedetermination of cefixime trihydrate (CFX) in the presence of its acid and alkali degradation products without prior separation. In the first method, secondderivative (2D) and first derivative (1D) spectrophotometry was applied to the absorption spectra of CFX and its acid (2D) or alkali (1D) degradation products by measuring the amplitude at 289 and 308 nm, respectively. The second method was a first derivative (1DD) ratio spectrophotometric method where the peak amplitudes were measured at 311 nm in presence of the acid degradation product, and 273 and 306 nm in presence of its alkali degradation product. The third method was ratio subtraction spectrophotometry where the drug is determined at 286 nm in laboratory-prepared mixtures of CFX and its acid or alkali degradation product. The fourth method was based on dualwavelength analysis; two wavelengths were selected at which the absorbances of one component were the same, so wavelengths 209 and 252 nm were used to determine CFX in presence of its acid degradation productand 310 and 321 nm in presence of its alkali degradation product. The fifth method was bivariate spectrophotometric calibration based on four linear regression equations obtained at the wavelengths 231 and 290 nm, and 231 and 285 nm for the binary mixture of CFX with either its acid or alkali degradation product, respectively. The developed methods were successfully applied to the analysis of CFX in laboratory-prepared mixtures and pharmaceutical formulations with good recoveries, and their validation was carried out following the International Conference on Harmonization guidelines. The results obtained were statistically compared with each other and showed no significant difference with respect to accuracy and precision.

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.  

Comparative Study for the Assay of Plant Derived Chemicals in Pharmaceutical Formulation Using Methods Dependent on Factorized Spectra

2021 ◽  
Author(s):  
Nesma M Fahmy ◽  
Adel M Michael
Keyword(s):  
Pharmaceutical Formulations ◽  
Pharmaceutical Formulation ◽  
Ternary Mixtures ◽  
Ratio Method ◽  
The Novel ◽  
Naturally Occurring ◽  
Accuracy And Precision ◽  
Validation Parameters ◽  
Significant Difference

Abstract Background Modern built-in spectrophotometer software supporting mathematical processes provided a solution for increasing selectivity for multicomponent mixtures. Objective Simultaneous spectrophotometric determination of the three naturally occurring antioxidants—rutin(RUT), hesperidin(HES), and ascorbic acid(ASC)—in bulk forms and combined pharmaceutical formulation. Method This was achieved by factorized zero order method (FZM), factorized derivative method (FD1M), and factorized derivative ratio method (FDRM), coupled with spectrum subtraction(SS). Results Mathematical filtration techniques allowed each component to be obtained separately in either its zero, first, or derivative ratio form, allowing the resolution of spectra typical to the pure components present in Vitamin C Forte® tablets. The proposed methods were applied over a concentration range of 2–50, 2–30, and 10–100 µg/mL for RUT, HES, and ASC, respectively. Conclusions Recent methods for the analysis of binary mixtures, FZM and FD1M, were successfully applied for the analysis of ternary mixtures and compared to the novel FDRM. All were revealed to be specific and sensitive with successful application on pharmaceutical formulations. Validation parameters were evaluated in accordance with the International Conference on Harmonization guidelines. Statistical results were satisfactory, revealing no significant difference regarding accuracy and precision. Highlights Factorized methods enabled the resolution of spectra identical to those of pure drugs present in mixtures. Overlapped spectra of ternary mixtures could be resolved by spectrum subtraction coupled FDRM (SS-FDRM) or by successive application of FZM and FD1M.

Selective Determination of Entecavir in the Presence of Its Oxidative Degradate by Spectrophotometric and Chromatographic Methods

2021 ◽  
Author(s):  
Heba M El-Sayed ◽  
Laila E Abdel Fattah ◽  
Hisham E Abdellatef ◽  
Maha A Hegazy ◽  
Mai M Abd El-Aziz
Keyword(s):  
High Selectivity ◽  
Oxidative Degradation ◽  
Hplc Method ◽  
Peak Amplitude ◽  
Quality Analysis ◽  
Official Method ◽  
Selective Determination ◽  
Significant Difference ◽  
Development And Validation

Abstract Background Entecavir (ENT) is an antiretroviral agent prescribed for treatment of HBV and HIV. Objective Development and validation of three simple, sensitive, selective, and precise methods for determination of ENT in presence of its oxidative degradation product (ENT deg.). Methods The first method was based on second derivative (D2) spectrophotometry through measuring the peak amplitude of D2 spectra at 293.6 nm. The second one is mean centering of the ratio spectra (MCR), which allowed measuring the peak amplitude at 280.0 nm. While the third method was HPLC; where ENT was separated from ENT deg. using Zobrax C18column and methanol: water (30:70, v/v), pH 3 as a mobile phase. The three developed methods were validated according to ICH guidelines. Results Linearity range of ENT was 5.00–50.00 μg/mL for both D2and MCR. However, higher sensitivity was achieved using HPLC (1.00–50.00 μg/mL). Accuracy of ENT were 100.60%±0.547, 101.55%±1.2071 and 100.61%±1.207 for D2, MCR and HPLC methods, respectively, and precision was within 1.280. Conclusions The developed methods were successfully applied for the determination of ENT in Tecavir® tablets without interference from ENT deg. They showed no significant difference compared with the official method as well as they could be applied in the quality analysis of ENT with high selectivity, accuracy, and precision. Highlights ENT was quantified using two spectrophotometric (D2 and MCR) methods and an HPLC method in presence of ENT deg. The proposed methods were applied to analysis of ENT tablets with high selectivity, sensitivity, and accuracy.

scholarly journals New Kinetic Spectrophotometric Method for Determination of Folic Acid in Pharmaceutical Formulations

2015 ◽  
Vol 50 ◽  
pp. 169-178
Author(s):  
Mouhammed Khateeb ◽  
Basheer Elias ◽  
Fatema Al Rahal
Keyword(s):  
Folic Acid ◽  
Spectrophotometric Method ◽  
Pharmaceutical Formulations ◽  
Fixed Time ◽  
Rate Data ◽  
Sulfuric Acid Medium ◽  
Significant Difference ◽  
Kinetic Spectrophotometric ◽  
Comparison Of The Results

A simple and sensitive kinetic spectrophotometric method has been developed for the determination of folic acid (FA) in bulk and pharmaceutical Formulations. The method is based on the oxidation of FA by Fe (III) in sulfuric acid medium. Fe (III) subsequently reduces to Fe (II) which is coupled with potassium ferricyanide to form Prussian blue. The reaction is followed spectrophotometrically by measuring the increase in absorbance at λmax 725 nm. The rate data and fixed time methods were adopted for constructing the calibration curves. The linearity range was found to be 1–20 μg mL-1 for each method. The correlation coefficient was 0.9978 and 0.9993, and LOD was found to be 0.91 and 0.09 μg mL-1 for rate data and fixed time methods, respectively. The proposed method has been successfully applied to the determination of FA in formulations with no interference from the excipients. Statical comparison of the results shows that there is no significant difference between the proposed and pharmacopoeial methods

Microsized Graphite Sensors for Potentiometric Determination of Cyclobenzaprine Hydrochloride in Pure Powder, Tablets, and Plasma

2011 ◽  
Vol 94 (6) ◽  
pp. 1807-1814 ◽  
Author(s):  
Nesrin K Ramadan ◽  
Hala E Zaazaa ◽  
Hanan A Merey
Keyword(s):  
Polyvinyl Chloride ◽  
International Union ◽  
Electroactive Material ◽  
Significant Difference ◽  
Intact Drug ◽  
Sensitivity And Selectivity ◽  
Ph Range ◽  
The U.S ◽  
Chloride Matrix

Abstract Two cyclobenzaprine hydrochloride (CZ) microsized graphite selective sensors were investigated with dibutylsebacate as a plasticizer in a polymeric matrix of carboxylated polyvinyl chloride (PVC-COOH) in the case of sensor 1, based on the interaction between the drug and the dissociated COOH groups in the PVC-COOH. Sensor 2 was based on the interaction between the drug and ammonium reineckate, which acted as anionic electroactive material in the presence of polyvinyl chloride matrix. The two sensors were constructed by using 2-hydroxy propyl β-cyclodextrin as an ionophore, which has a significant influence on increasing the membrane sensitivity and selectivity of both sensors. Fast and stable Nernstian responses of 1 × 10–5–1 × 10–2 and 1 × 10m–4–1 × 10–2 M for the two sensors, respectively, with slopes of 58.6 and 55.5 mV/decade, respectively, over the pH range 2–4 were obtained. The proposed method displayed useful analytical characteristics for determination of CZ in its pure powder form with average recoveries 99.95 ± 0.23 and 99.61 ± 0.34% for sensors 1 and 2, respectively, and in plasma with good recoveries. The sensors were also used to determine the intact drug in the presence of its degradate and, thus, could be used as stability-indicating methods. The obtained results by the proposed methods were statistically analyzed and compared with those obtained by the U.S. Pharmacopeia method; no significant difference for either accuracy or precision was observed. Results obtained with the two electrodes revealed their performance characteristics, which were evaluated according to International Union of Pure and Applied Chemistry recommendations.

scholarly journals Different spectrophotometric and TLC-densitometric methods for determination of olmesartan medoxomil and hydrochlorothiazide and their degradation products

2018 ◽  
Vol 9 (4) ◽  
pp. 400-407 ◽  
Author(s):  
Selvia Maged Adly ◽  
Maha Mohamed Abdelrahman ◽  
Nada Sayed Abdelwahab ◽  
Nourudin Wageh Ali
Keyword(s):  
Multivariate Calibration ◽  
Degradation Products ◽  
External Validation ◽  
Olmesartan Medoxomil ◽  
Partial Least Square ◽  
Least Square ◽  
Pharmaceutical Dosage Form ◽  
Calibration Models ◽  
Significant Difference

In this work, multivariate calibration models and TLC-densitometric methods have been developed and validated for quantitative determination of olmesartan medoxomil (OLM) and hydrochlorothiazide (HCZ) in presence of their degradation products, olmesartan (OL) and salamide (SAL), respectively. In the first method, multivariate calibration models including principal component regression (PCR) and partial least square (PLS) were applied. The wavelength range 210-343 nm was used and data was auto-scaled and mean centered as pre-processing steps for PCR and PLS models, respectively. These models were tested by application to external validation set with mean percentage recoveries 99.78, 100.01, 100.41 and 100.46% for OLM, HCZ, OL and SAL, respectively, for PLS model and also, 100.22, 100.40, 102.25 and 100.13% for them, respectively, for PCR model. The second method is TLC-densitometry at which the chromatographic separation was carried out using silica gel 60F254 TLC plates and the developing system consisted of a mixture of ethyl acetate:chloroform:methanol: formic acid:tri-ethylamine (60:40:4:4:1, by volume) with UV-scanning at 254 nm. The developed methods were successfully applied for determination of OLM and HCZ in their pharmaceutical dosage form. Also, statistical comparison was made between the developed methods and the reported method using student’s-t test and F-test and results showed that there was no significant difference between them concerning both accuracy and precision.

scholarly journals Development of a Solid-Phase Extraction Method for Determination of Pheophorbide a and Pyropheophorbide a in Health Foods by Liquid Chromatography

2004 ◽  
Vol 87 (4) ◽  
pp. 937-942 ◽  
Author(s):  
Harumi Oshima ◽  
Eiji Ueno ◽  
Isao Saito ◽  
Hiroshi Matsumoto
Keyword(s):  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Solid Phase ◽  
Reversed Phase ◽  
Official Method ◽  
Phase Extraction ◽  
Pheophorbide A ◽  
Significant Difference ◽  
Spe Method

Abstract A simple solid-phase extraction (SPE) method was developed for the liquid chromatography (LC) determination of pheophorbide (Phor) a and pyropheophorbide (Pyro) a in health foods such as chlorella, spirulina, etc. The food sample was extracted with 85% (v/v) acetone. The extract was acidified with hydrochloric acid and loaded on a C18 cartridge. After washing with water, Phor a and Pyro a were eluted with the LC mobile phase. Phor a and Pyro a were separated by isocratic reversed-phase LC and quantitated by fluorescence detection. The recoveries for spiked samples of chlorella and the extract were 87.1–102.0%. Commercial health foods (chlorella, spirulina, aloe, kale, Jews mallow, and green tea leaves) were analyzed using the SPE method. The values found for Phor a and Pyro a ranged from 2 to 788 μg/g and from <1 to 24 μg/g, respectively. There was no significant difference between the SPE method and the official method in Japan (spectrophotometry after liquid–liquid extraction). The advantages of the SPE method are the short extraction times, lack of emulsions, and reduced consumption of organic solvents compared with the official method in Japan. The SPE method is considered to be useful for the screening of Phor a and Pyro a in health foods.

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