Fathalla Belal
Mansoura University, Depatment of Analytical Chemistry, Faculty Member
- 1. Ph. D. Anal Chem. Mansoura University, Egypt Feb.19832. Post-Doc Georgia University , Athens USA, 1984-19853. Visi... more1. Ph. D. Anal Chem. Mansoura University, Egypt Feb.19832. Post-Doc Georgia University , Athens USA, 1984-19853. Visiting Professor Bradford University,Bradford,UK 19874. Visiting Professor Shizouka University, Shizouka ,Japan 19885. Alexander von Humboldt Scholar, Frankfurt University, Frankfurt,Germany, 1989-1991.6.Frofessor of Anal.Che. Fac. Pharm.Mansoura University, Mansoura,Egypt, April 1992 till present7. Visiting Professor Wurzburg University, Wurzburg, Germany 20088. Visitin Professor Marburg University, Marburg ,Germany 2011edit
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... 3. Ibamor Vials (Each vial 100.11 100.05 99.90 contains Amoxycillin t0.102 iOo.164 k0.30 Sodium equivalent to 250 mg Amoxyoillin ... F. 0. Snell and CT Snell, "Colorimetric Methods of Analysis" Van Nastrand Reinhold CO., N.... more
... 3. Ibamor Vials (Each vial 100.11 100.05 99.90 contains Amoxycillin t0.102 iOo.164 k0.30 Sodium equivalent to 250 mg Amoxyoillin ... F. 0. Snell and CT Snell, "Colorimetric Methods of Analysis" Van Nastrand Reinhold CO., N. Y. 3rd. ed., Vol. 111. Page 104 (1953). ...
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Two simple and sensitive analytical assay methods using spectrophotometry and spectrofluorimetry techniques were developed for the estimation of succinylcholine chloride (SUC) in pharmaceutical preparations. The suggested methods are... more
Two simple and sensitive analytical assay methods using spectrophotometry and spectrofluorimetry techniques were developed for the estimation of succinylcholine chloride (SUC) in pharmaceutical preparations. The suggested methods are based on the formation of an ion pair complex formed between the drug and eosin Y spectrophotometrically (Method I), or the suppressive effect of succinylcholine on the native fluorescence property of eosin Y (Method II). The spectrophotometric method (Method I) involves measuring the absorbance of the complex between succinylcholine and eosin Y at 550 nm in Britton Robinson buffer of pH 3. However, the spectrofluorimetric method (Method II) involves measuring the quenching effect of the studied drug on the native fluorescence property of eosin Y at the same pH at 550 nm after excitation at 480 nm. The absorbance versus concentration of the drug is rectilinear over the range of 0.5 to 15 μg/ml. The formation constant was 3.5 × 104 and the Gibb's fre...
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A simple, sensitive and rapid micellar liquid chromatographic method was developed and validated for simultaneous determination of four drugs, namely, paracetamol (PAR), tizanidine (TZD), aceclofenac (ACF) and nimesulide (NMD). Good... more
A simple, sensitive and rapid micellar liquid chromatographic method was developed and validated for simultaneous determination of four drugs, namely, paracetamol (PAR), tizanidine (TZD), aceclofenac (ACF) and nimesulide (NMD). Good chromatographic separation was achieved using Cyano column and micellar mobile phase consisting of 120 mM sodium dodecyl sulfate, 25 mM phosphate buffer and 10% (V/V) butanol. The pH was adjusted to three using phosphoric acid. The total retention time was below 10 min. The analysis was performed at a flow rate of 1 mL/min and a column temperature of 40°C with direct UV detection at 230 nm. Diclofenac sodium was used as the internal standard. The proposed method was validated according to the ICH guidelines and was successfully applied to the analysis of these drugs in their tablet dosage forms with high accuracy. Limits of detection were found to be 0.03, 0.07, 0.033 and 0.11 μg/mL for PAR, ACF, TZD and NMD, respectively. The high sensitivity of develop...
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The present paper describes a developed and validated simple, highly sensitive and cost-effective spectrofluorometric method for determination of clonazepam (CNP). The proposed method depends on forming a highly fluorescent product... more
The present paper describes a developed and validated simple, highly sensitive and cost-effective spectrofluorometric method for determination of clonazepam (CNP). The proposed method depends on forming a highly fluorescent product through the reduction of CNP with Zn/HCl. The produced fluorophore exhibits a strong fluorescence at λem 350 nm after excitation at λex 250 nm. The use of carboxymethylcellulose (CMC) greatly enhanced the fluorescence intensity of the produced fluorophore to the extent of about 100%. Calibration curve showed good linear regression (r(2) > 0.9998) within test ranges of 20-400 ng ml(-1) with a lower detection limit of 0.67 ng ml(-1) and lower quantification limit of 2.22 ng ml(-1) upon using CMC. The method was successfully applied to the analysis of CNP in its pharmaceutical formulations and the results were in agreement with those obtained using a reference method. Furthermore, the content uniformity testing of the tablets was also performed. The appl...
Research Interests: Humans, Calibration, Zinc, Luminescence, Buffers, and 12 moreTablets, Reproducibility of Results, Sensitivity and Specificity, Freezing, Hydrochloric Acid, Drug Stability, Hydrogen-Ion Concentration, Sodium Carboxymethylcellulose, Biochemistry and cell biology, Solvents, clonazepam, and limit of detection
A facile, rapid, and highly sensitive microchip-based electrokinetic chromatographic method was developed for the simultaneous analysis of two gabapentinoid drugs, gabapentin (GPN) and pregabalin (PGN). Both drugs were first reacted with... more
A facile, rapid, and highly sensitive microchip-based electrokinetic chromatographic method was developed for the simultaneous analysis of two gabapentinoid drugs, gabapentin (GPN) and pregabalin (PGN). Both drugs were first reacted with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) via nucleophilic substitution reactions to yield highly fluorescent products with λex/em 470/540nm. Analyses of both fluorescently labeled compounds were achieved within 200s in a poly(methyl methacrylate) (PMMA) microchip with a 30mm separation channel. Optimum separation was achieved using a borate buffer (pH 9.0) solution containing methylcellulose and β-cyclodextrin (β-CD) as buffer additives. Methylcellulose acted as a dynamic coating to prevent adsorption of the studied compounds on the inner surfaces of the microchannels, while β-CD acted as a pseudo-stationary phase to improve the separation efficiency between the labeled drugs with high resolution (Rs>7). The fluorescence intensities of the l...
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A simple, fast, sensitive and stability-indicating derivative spectrofluorimetric method is presented for the assay of zopiclone (ZOP), a drug with hypnotic effect, and its main degradation product and major contaminant,... more
A simple, fast, sensitive and stability-indicating derivative spectrofluorimetric method is presented for the assay of zopiclone (ZOP), a drug with hypnotic effect, and its main degradation product and major contaminant, 2-amino-5-chloropyridine (ACP). The method is based on measuring the inherent fluorescence intensity of both drugs at λex=300nm in methanol, then differentiation using D1 (first derivative technique). The developed method was found to be rectilinear over a range of 0.2-4μg/mL of ZOP and 4-100ng/mL of ACP. The limits of detection were 0.05μg/mL of ZOP and 0.2ng/mL of ACP with the limit of quantitation of 0.17μg/mL of ZOP and 0.7ng/mL of ACP. The outcoming results of the proposed method were compared to those obtained by a reference method showing no significant statistical difference between them concerning precision and accuracy. Additionally, the developed method was applied for detecting ACP in spiked human urine and plasma specimens as a tool of clinical evidence of zopiclone intake that can be easily implemented in forensic laboratories. The proposed method was validated as per ICH guidelines.
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... The value of an, is calculated from E = E m -- (0.059/ana) log ~ . At pH 10, an, was found to be 1.28, which gives Z = 1.19, suggesting that 2 hydrogen ions are consumed in the electrode reaction. ... 1985, 47, 190. [.8] MS Mahrous,... more
... The value of an, is calculated from E = E m -- (0.059/ana) log ~ . At pH 10, an, was found to be 1.28, which gives Z = 1.19, suggesting that 2 hydrogen ions are consumed in the electrode reaction. ... 1985, 47, 190. [.8] MS Mahrous, AS Issa, NS Soliman, Alexandria J. Pharm. Sci. ...
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The voltammetric behaviour of cyproterone acetate (CPA) was studied using direct current (DCt) and differential pulse polarography (DPP). The drug manifests cathodic waves over the pH range of 4-11.8. In Britton-Robinson buffer (BRb) of... more
The voltammetric behaviour of cyproterone acetate (CPA) was studied using direct current (DCt) and differential pulse polarography (DPP). The drug manifests cathodic waves over the pH range of 4-11.8. In Britton-Robinson buffer (BRb) of pH 10, the diffusion current-concentration relationship was found to be rectilinear over the range 3.2-32 μg/mL and 0.5-14 μg/mL using DCt and DPP modes, respectively, with minimum limits of detection (LOD) of 0.13 μg/mL using the DDP. The diffusion-current constant (Id) was 9.29 ± 0.046 (n=9). The proposed method was successfully applied to the determination of the studied compound in its formulations. The mean percentage recoveries in tablets were 99.48 ± 1.25 and 100.01 ± 1.07 (n=4) using DCt and DPP modes, respectively. The results obtained were in agreement with those of the reference method. A proposal for the electrode reaction was postulated.
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Based on the interfacial adsorptive character of danazol onto the hanging mercury drop electrode (HMDE), a simple and sensitive square-wave adsorptive stripping voltammetric (SW-AdSV) procedure for the electrochemical analysis of this... more
Based on the interfacial adsorptive character of danazol onto the hanging mercury drop electrode (HMDE), a simple and sensitive square-wave adsorptive stripping voltammetric (SW-AdSV) procedure for the electrochemical analysis of this drug in pharmaceutical formulations has been developed and validated. Cyclic and SW-AdSV voltammograms showed a single well-defined irreversible cathodic peak. Various chemical and instrumental parameters affecting the monitored electroanalytical response were investigated and optimized for the danazol determination. Under these optimized conditions the SW-AdSV peak current showed a linear dependence on drug concentration over the range 7.5x10(-8)-3.75x10(-7) mol l-1 (r=0.999) with estimated detection limit (at a S/N ratio of 3) of 5.7x10(-9) mol l-1 (1.78 ng ml-1). A mean recovery of 100.9+/-1.2% and relative standard deviation of 1.07% were achieved. Possible interferences by substances usually present in the pharmaceutical tablets and formulations were also evaluated. The proposed electrochemical procedure was successfully applied for the determination of danazol in pharmaceutical capsules (Danol 100 mg) with mean recoveries of 100.48+/-0.87%. Results of the developed SW-AdSV method were comparable with those obtained by reported analytical procedures.
Research Interests: Analytical Chemistry, Electrochemistry, Response Surface Methodology, Adsorption, Pharmaceutical, and 13 moreElectrolytes, Reproducibility of Results, Food Sciences, Central Composite Design, Sensitivity and Specificity, Capsules, Hydrogen-Ion Concentration, Response surface, False Negative, Danazol, False Positive, Estrogen antagonists, and Pharmacology and pharmaceutical sciences
A stability‐indicating reversed‐phase high performance liquid chromatographic method was developed for the analysis of the antipsychotic drug quetiapine. Quetiapine was determined in presence of two of its degradation products; quetiapine... more
A stability‐indicating reversed‐phase high performance liquid chromatographic method was developed for the analysis of the antipsychotic drug quetiapine. Quetiapine was determined in presence of two of its degradation products; quetiapine N‐oxide and quetiapine lactam. The analysis was carried out using a 250 mm×4.6 mm i.d., 5 µm particle size Zorbax SB‐Phenyl column. Mobile phase containing a mixture of acetonitrile and 0.02 M phosphate buffer (5050) at pH=5.5 was pumped at a flow rate of 1 mL/min with UV detection at 254 nm. The method showed good linearity in the range of 0.08–20 µg/mL with limit of detection (S/N=3) 0.03 µg/mL (3.3×10−8 M). The suggested method was successfully applied for the analysis of quetiapine in bulk, tablets, and human plasma with average recoveries of 99.96±1.25%, 101.37±0.481%, and 100.82±1.53%, respectively. The proposed method was also applied for the determination of quetiapine in the presence of some co‐administered drugs as clomipramine, carbamaze...
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Summary A reversed-phase, High-performance Liquid chromatographic method for the simultaneous determination of phenazopyridine and nitrofurantoin in tablets is described. An aminopropyl-silica (APS-Hypensil) 5μm column and a mobile phase... more
Summary A reversed-phase, High-performance Liquid chromatographic method for the simultaneous determination of phenazopyridine and nitrofurantoin in tablets is described. An aminopropyl-silica (APS-Hypensil) 5μm column and a mobile phase consisting of Methanol:H2O: 0.05M sodium dihydrogen phosphate (50∶45∶5) were used. Calibration curves were linear over the concentration range 2–20μg/ml, with minimum detectability of 10ng/ml for both drugs. The method was applied to tablets
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A rapid, stability indicating hydrophilic interaction liquid chromatography (HILIC) method was developed for the determination of lamotrigine and its induced alkaline degradation product. The separation was performed on an unmodified... more
A rapid, stability indicating hydrophilic interaction liquid chromatography (HILIC) method was developed for the determination of lamotrigine and its induced alkaline degradation product. The separation was performed on an unmodified silica column adopting UV detection at 290 nm with flow rate of 1.5 mL min. The mobile phase consisted of a mixture of acetonitrile:ammonium formate 0.01 M (85: 15, v/v) and the pH was
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Research Interests: Analytical Chemistry, Refrigeration, Oxytocin, Temperature, Cephalosporins, and 14 moreHigh Pressure Liquid Chromatography, Anti-Bacterial Agents, Time Factors, Drug Packaging, Sensitivity and Specificity, Freezing, Hydrolysis, Drug Compounding, Drug Stability, Hydrogen-Ion Concentration, Oxidation-Reduction, guidelines as topic, drug storage, and Pharmacology and pharmaceutical sciences
In this study, a micellar liquid chromatography method is proposed for determination of tizoxanide, the active metabolite of nitazoxanide, using a mobile phase consisting of 0.1 M sodium dodecyl sulphate, 8% n-propanol and 0.3%... more
In this study, a micellar liquid chromatography method is proposed for determination of tizoxanide, the active metabolite of nitazoxanide, using a mobile phase consisting of 0.1 M sodium dodecyl sulphate, 8% n-propanol and 0.3% triethylamine in 0.02 M phosphoric acid.
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The voltammetric behavior of flubendazole was studied using direct current (DCt), differential pulse (DPP) and alternating current (ACt) polarography. The drug manifests a cathodic wave in 20% v/v formic acid solution. The wave was... more
The voltammetric behavior of flubendazole was studied using direct current (DCt), differential pulse (DPP) and alternating current (ACt) polarography. The drug manifests a cathodic wave in 20% v/v formic acid solution. The wave was characterized as being irreversible, diffusion-controlled with limited adsorption properties. The diffusion current-concentration relationship was found to be rectilinear over the range 3.2-14.4 microg/ml and 0.1 to 12.8 microg/ml, using DCt and DPP modes, respectively, with minimum detectability of 0.161 microg/ml (5.14 x 10(-7) M) and 0.0.057 microg/ml (1.82 x 10(-8) M) using DCt and DPP modes, respectively. Furthermore, the proposed method was applied to the in-vitro determination of flubendazole in spiked human urine and plasma adopting the DPP technique. The percentage recoveries were 100.20+/-0.62 and 97.42+/-0.95, respectively.
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1,3-Dibromodimethylhydantoin (DBH) is a stable dihalogen reagent. It can be used as an analytical reagent for certain analgesics. It gives stoichiometric results by direct titration in acid medium. The end point is detected visually or... more
1,3-Dibromodimethylhydantoin (DBH) is a stable dihalogen reagent. It can be used as an analytical reagent for certain analgesics. It gives stoichiometric results by direct titration in acid medium. The end point is detected visually or potentiometrically. Also spectrophotometric titrations have been attempted at 345 nm. In all cases the results of the analysis of the drugs studied either in the pure state or in their dosage forms comply with those given by N-bromo succinimide (NBS) and by the official methods, however this application is distinguished by simplicity and accuracy.
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... medium is proposed to be due to a nucleophilic reaction mechanism while the photostabilization of DF solutions in the presence of PABA, ascorbic acid ... multiband UV-254/366 nm, 215-250 volts, 50/60 Hz, 0.12 Amps, San Gabriel, USA)... more
... medium is proposed to be due to a nucleophilic reaction mechanism while the photostabilization of DF solutions in the presence of PABA, ascorbic acid ... multiband UV-254/366 nm, 215-250 volts, 50/60 Hz, 0.12 Amps, San Gabriel, USA) fixed to a wooden cabinet in a horizontal ...
Research Interests: Food and Food Sciences
A titrimetric method is described for the determination of three acetylenic hypnotics, namely ethchlorvynol, ethinamate, and methylpentynol carbamate, in bulk and in dosage forms. The method involves the use of either... more
A titrimetric method is described for the determination of three acetylenic hypnotics, namely ethchlorvynol, ethinamate, and methylpentynol carbamate, in bulk and in dosage forms. The method involves the use of either 1,3-dibromo-5,5-dimethylhydantoin (DBH), N-bromosuccinimide (NBS) or N-bromophthalimide (NBP) as titrants. A known excess volume of the reagent is added and, after the specified time, the residual reagent is determined iodometrically. This procedure permits semimicro determination (1-15 mg) of the drug. The procedure has been successfully applied to pharmaceutical dosage forms; the results agree well with those given by compendial methods. The stoichiometry of the reaction has been assessed and an explanation of the reaction pathway is presented.
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A simple and sensitive spectrophotometric method was developed for the determination of each of sertraline (SER) and paroxetine HCl (PXT) in dosage forms. The method is based upon reaction of PXT and SER with 2,4-dinitrofluorobenzene... more
A simple and sensitive spectrophotometric method was developed for the determination of each of sertraline (SER) and paroxetine HCl (PXT) in dosage forms. The method is based upon reaction of PXT and SER with 2,4-dinitrofluorobenzene (DNFB) to form colored products. The absorbance of the products were measured at 375and 390 nm for SER and PXT respectively. The absorbance concentration plots were rectilinear over the concentration rang of 1-10 and 2-20 μg/mL with lower detection limits (LOD) of 0.11 and 0.28 μg/mL and quantification limits (LOQ) of 0.32 and 0.85 μg/mL for SER and PXT, respectively. The developed method was successfully applied for the determination of SER and PXT in dosage forms. The common excipients and additives did not interfere in their determinations. There was no significant difference between the results obtained by the proposed and the reference methods regarding Student t-test and the variance ratio F-test respectively. A proposal of the reaction pathway was postulated.
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A new simple and sensitive kinetic spectrophotometric method is described for analysis of nizatidine (I) and ranitidine (II). The method involves the reaction of the drugs with alkaline potassium permanganate, whereby a green color... more
A new simple and sensitive kinetic spectrophotometric method is described for analysis of nizatidine (I) and ranitidine (II). The method involves the reaction of the drugs with alkaline potassium permanganate, whereby a green color peaking at 610 nm is produced. The reaction is monitored spectrophotometrically by measuring the rate of change of absorbance of the resulting manganate species at 610
Research Interests: Analytical Chemistry, Quantitative analysis, Humans, Copper, Amines, and 13 moreCalibration, Valproic Acid, Tablets, Reproducibility of Results, Vigabatrin, Food Sciences, Amino Acid Profile, Quantitative Analysis, Dosage Forms, Hydrogen-Ion Concentration, Gamma-Aminobutyric Acid, Molecular Structure, and Pharmaceutical Formulation
A highly sensitive spectrofluorometric method was developed for the determination of verapamil hydrochloride (VP HCl) in pharmaceutical formulations and biological fluids. The proposed method is based on investigation of the fluorescence... more
A highly sensitive spectrofluorometric method was developed for the determination of verapamil hydrochloride (VP HCl) in pharmaceutical formulations and biological fluids. The proposed method is based on investigation of the fluorescence spectral behavior of VP HCl in micellar systems, such as sodium dodecyl sulfate (SDS) and beta-cyclodextrin (beta-CD). In aqueous solutions of borate buffer of pH 9 and 8.5, VP HCI was well incorporated into SDS and beta-CD, respectively, with enhancement of its native fluorescence. The fluorescence was measured at 318 nm after excitation at 231 nm. The fluorescence intensity enhancements were 183 and 107% in SDS and in beta-CD, respectively. The fluorescence-concentration plots were rectilinear over the range of 0.02-0.2 and 0.02-0.25 microg/mL, with lower detection limits of 5.58 x 10(-3) and 3.62 x 10(-3) microg/mL in SDS and beta-CD, respectively. The method was successfully applied to the analysis of commercial tablets and the results were in g...
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A reversed phase high performance liquid chromatography (HPLC) method was developed for the determination of tauromustine (TM) in presence of its metabolited in biological fluids and its degradation products in tablets. The proposed HPLC... more
A reversed phase high performance liquid chromatography (HPLC) method was developed for the determination of tauromustine (TM) in presence of its metabolited in biological fluids and its degradation products in tablets. The proposed HPLC method was conducted using a lichrosorb C18 column [250 × 4 mm], with acetonitrile - water - acetate buffer pH5 (40: 55: 5) eluent, the detection was affected at 235 nm. The detector response was linear in the range 0.2–4 μg/ml for TM with minimum detectability (S/N=2) of 2 ng/ml. The proposed HPLC method was applied to the determination of TM in presence of its metabolites in biological fluids. The percentage recoveries of TM and its metabolites from spiked urine range from 93.1 to 92.9 and for plasma 90.3 to 89.6. The proposed HPLC method was used to study the kinetics of degradation of TM in standard solution as a function of temperature and alkalinity. TM degraded followed first-order kineties in agreement with the Arrhenius theory. The proposed...
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A reversed-phase high-performance liquid chromatographic (HPLC) method was developed for use in kinetic studies of α-methylopa (MD). The proposed method was further applied to the determination of MD in sustained release capsules and in... more
A reversed-phase high-performance liquid chromatographic (HPLC) method was developed for use in kinetic studies of α-methylopa (MD). The proposed method was further applied to the determination of MD in sustained release capsules and in the presence of its industrial impurity, 3-O-methylmethyldopa (MMD). The detector response was linear in the range 0.5–200 μg/ml for MD and MMD. Replicate injections of both compounds gave relative standard deviations of 0.54 and 0.62%, respectively. The mean recoveries of MD from raw material and sustained release capsules were 99.71–100.2% and 99.5–100. 1%, respectively. The proposed HPLC method was used to study the kinetics of degradation of MD in raw material and in sustained release capsules as a function of temperature, pH, humidity and exposure to UV radiation. MD degradation followed first-order kinetics and gave a linear relationship, in agreement with the Arrhenius theory, for all the incubation media studied. The activation energy for MD ...
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A simple and sensitive kinetic spectrofluorometric method was developed for the determination of some calcium channel blockers namely, verapamil hydrochloride, diltiazem hydrochloride, nicardipine hydrochloride and flunarizine. The method... more
A simple and sensitive kinetic spectrofluorometric method was developed for the determination of some calcium channel blockers namely, verapamil hydrochloride, diltiazem hydrochloride, nicardipine hydrochloride and flunarizine. The method is based upon oxidation of the studied drugs with cerium (IV) ammonium sulphate in acidic medium. The fluorescence of the produced Ce (III) was measured at 365 nm after excitation at 255 nm. The different experimental parameters affecting the development and stability of the reaction product were carefully studied and optimized. The fluorescence-concentration plots were rectilinear for all the studied compounds over the concentration range of 0.01 to 0.12 μg mL(-1). The limits of detections for the studied compounds ranged from 2.93 × 10(-3) to 0.012 μg mL(-1) and limits of quantification from 9.76 × 10(-3) to 0.04 μg mL(-1) were obtained. The method was successfully applied to the analysis of commercial tablets. The results obtained were in good a...
Two accurate analytical methods were developed for the resolution and analysis of a binary mixture of acemetacin (ACE) and chlorzoxazone (CLZ). The first method depends on chromatographic separation of ACE and CLZ using a Shimadzu VP-ODS... more
Two accurate analytical methods were developed for the resolution and analysis of a binary mixture of acemetacin (ACE) and chlorzoxazone (CLZ). The first method depends on chromatographic separation of ACE and CLZ using a Shimadzu VP-ODS column. Mobile phase containing 0.075 M sodium dodecyl sulphate, 0.3 % triethylamine, 10 % n-propanol in 0.02 M orthophosphoric acid of pH 5.5 was pumped at a flow rate of 1 mL/min. with UV detection at 210 nm. The method was further extended to the determination of acemetacin (ACE) and chlorzoxazone (CLZ) in spiked human plasma without prior extraction. For the second method, it depends on measuring the amplitudes of the first derivative spectra at 281.75 nm for ACE and 242.53 nm for CLZ.
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Two simple, sensitive and accurate spectrophotometric methods have been developed for the determination of bumadizone in bulk drug and its tablets. Both methods based on the oxidative coupling reaction with 3-methyl-2-benzothiazolinone... more
Two simple, sensitive and accurate spectrophotometric methods have been developed for the determination of bumadizone in bulk drug and its tablets. Both methods based on the oxidative coupling reaction with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) and measuring the absorbance of the developed colors by direct or kinetic spectrophotometric method. Upon treatment of a mixture of the chromogenic reagent and drug with cerium (IV) ammonium sulfate (method I) or ferric chloride (method I), a red or violet color was developed immediately or after 30 minutes measurable at 557 nm for method I or II, respectively. The absorbance-concentration plots were rectilinear over the ranges of 1-10 μg/mL (r = 0.9999) for method I and 2-16 μg/mL (r = 0.9998) for method II. The detection limits were 0.15 and 0.27 μg/mL & the quantitation limits were 0.46 and 0.84 μg/mL for methods I and II, respectively. Different experimental parameters affecting the development and stability of the r...