Browsing by Author "Salem, Hesham"

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Column Performance Study of Different Variants of Liquid Chromatographic Technique: An Application on Pharmaceutical Ternary Mixtures Containing Tetryzoline
(Oxford University Press, 2015) Salem, Hesham; Y Hassan, Nagiba; M Lotfy, Hayam; S Saleh, Sarah
High-performance liquid chromatography (HPLC), ultra-performance liquid chromatography (UPLC) and rapid resolution liquid chromatographic (RRLC) methods have been developed and validated for the separation and quantitation of both or either of two ternary mixtures present in ophthalmic solutions. The first mixture contains chloramphenicol, dexamethasone sodium phosphate and tetryzoline HCl (TZH); while the second one contains ofloxacin, prednisolone acetate and TZH. Both preparations contain benzalkonium chloride as a preservative. The columns used were a HPLC column (C18 5 µm particle size), a RRLC column (C18 2.6 µm particle size) and a UPLC column (C18 1.7 µm particle size). A comparative study was conducted to illustrate the effect of the change in column particle size and dimensions on the other chromatographic conditions, backpressure and the separation of both ternary mixtures. The methods were validated as per ICH guidelines where accuracy, repeatability, interday precision and robustness were found to be within the acceptable limits. The RRLC column provided shorter run time and better resolution than HPLC, while the UPLC column gave the shortest run time for all columns. The RRLC column resulted in minimum backpressure, so it could be used with any HPLC instrument, which makes the method more practical and economic. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observe
New developed spectrophotometric method for simultaneous determination of salmeterol xinafoate and fluticasone propionate in bulk powder and Seritide® diskus inhalation
(Elsevier, 2012) Samir, Ahmed; Salem, Hesham; Abdelkawy, Mohammad
A new simple, accurate, precise, rapid and economical method was developed for the simultaneous determination of Salmeterol xinafoate and Fluticasone propionate in their binary mixture in bulk powder and Seritide diskus® inhalation. The new method depends on new calculations using the mixture’s absorbance at 225 and 256.5 nm where the absorptivity of Salmeterol xinafoate is double the absorptivity of Fluticasone propionate, while the content of Salmeterol xinafoate was determined by measuring the absolute value of the first derivative ultraviolet curves at 352 nm, without interference from Fluticasone propionate. The proposed method was validated and the results obtained by adopting the proposed method were statistically analyzed and compared with those obtained by reported methods.
Optimization of two charge transfer reactions for colorimetric determination of two beta 2 agonist drugs, salmeterol xinafoate and salbutamol, in pharmaceutical and biological samples
(Elsevier, 13/09/2021) Samir, Ahmed; Salem, Hesham; Abdelkawy, Mohammed
Beta 2 agonists are well known for their use in the treatment of asthma and COPD however in the last few years new indications of beta 2 agonist appeared like reduction of local fats and treatment of preterm labour which required the formulation of new dosage forms and administration strategies. The new developments require accurate, economic and feasible methods the determination of these drugs to facilitate testing the newly introduced dosage forms and to study the pharmacokinetics and pharmacodynamics regarding the modern uses. In this study two rapid, sensitive and economic colorimetric methods for the determination of salmeterol xinafoate and salbutamol in pharmaceutical dosage forms and spiked plasma were developed and validated. The developed methods depends on the optimized reaction of the studied drugs with two charge transfer reagents, 2,3-dochloro-5,6-dicyano-1,4-benzoquonone (DDQ) and chloranilic acid (CA) to produce coloured complexes measured at 460 and 529nm for DDQ and CA respectively. The developed methods showed high accuracy of 99.52±1.108, 101.03±0.389, 100.04±1.520 and 100.3±0.951 for salmetrol xinafoate and salbutamol with DDQ and CA respectively. The proposed methods were successfully used for the determination of the studied drugs in their dosage forms and spiked plasma with high accuracy and precision and the results were compared to reported methods.
Quantitative determination of citalopram hydrobromide by spectro-photometry and chemometry in presence of its degradation products and additivesin pharmaceutical preparation
(Analytical Chemistry: An Indian Journal, 2016) M. El-Maraghy, Christine; M. Amer, Sawsan; Salem, Hesham; Nebsen, Marianne
Simple, accurate, sensitive and validated UV stability-indicating spectro- photometric and chemometric methods were developed for determination of Citalopram Hydrobromide (CT) in presence of its alkaline, oxidative degradation products and in its pharmaceutical preparation. Method (A) is a successive derivative ratio spectrophotometricone, which depends on the successive derivative ofratio spectra in two steps and measuring Citalopram Hydrobromide at 277nm and 293nm. Method (B) is mean centering of ratio spectra which dependson using the mean centered ratio spectra in two successive steps and measuring the mean centeredvalues of the second ratio spectra at 237nm and method (C) used two chemometric techniques ; principal component regression(PCR) and partial least-squares (PLS). The proposed methods werechecked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceuticalformulation containing Citalopram Hydrobromide. The proposed methods were vali- dated according to the ICH guidelines. The obtained results were statisti- cally compared with those obtained froma compendial HPLC method,showing no significant difference with respect to accuracy and precision.
Simultaneous determination of metronidazole and diiodohydroxyquine in bulk powder and paramibe compound tablets by TLC-densitometry and HPLC
(Pharmaceut Anal Acta, 2012) Salem, Hesham; M. Riad, Safaa; R. Rezk, Mamdouh; Ahmed, Kholoud
Two sensitive and precise chromatographic methods were developed and validated for simultaneous determination of metronidazole (MTR) and diiodohydroxyquin (DIQ) in pharmaceutical preparation. The techniques adopted for quantification are coupled TLC-densitometry and HPLC. A mixture of chloroform, toluene, ethanol and acetic acid (9:9:1:1, v/v/v/v) was used as the developing solvent for TLC-densitometry. A mixture of methanol and acetonitrile, (96:4, v/v) was used as a mobile phase for HPLC at 0.6 mL min-1 flow rate and UV detection at 254 nm. Linearity was obtained in concentration range of 0.5-10 µg spot-1 for DIQ and 1-20 µg spot-1 for MTR applying TLC-densitometry and 0.005-0.5 mg mL-1 for DIQ and 0.01-0.5 mg mL-1 for MTR applying HPLC. The selectivity of the proposed methods was checked using laboratory prepared mixtures. The proposed methods were successfully applied to the analysis of MTR and DIQ in their mixture and in pharmaceutical dosage forms without interference from other additives.
Simultaneous determination of pamabrom and paracetamol in bulk powders and womankit tablets using spectrophotometric and chemometric-assisted spectrophotometric methods
(2013) Salem, Hesham; Mohamed, Dalia
Fivemethodswere developed for simultaneous determination of pamabrom and paracetamol without previous separation. In the first and second methods pamabrom and paracetamol were determined using second and third derivative UV spectrophotometry with zero crossing measurement at 301 and 265 nm for second derivative method and at 290 and 257 nm for third derivative method, for pamabromand paracetamol, respectively. The third method depends on first derivative of the ratios spectra by measurements of the amplitudes at 271 nmfor pamabromand at 258 nm for paracetamol. The fourth one depends on two wavelength measurement for the total content of the two drugs at 222 and 265 nm, while the content of paracetamol was determined by measuring the absolute value of the first derivative curve at 243 nm. The fifth method describes the use of multivariate spectrophotometric calibration for the simultaneous determination of the analyzed binarymixture where the resolution is accomplished by using classical least squares regression analysis. All the proposed methods were extensively validated and the results obtained were statistically analyzed and compared with those obtained by official methods. The results obtained were statistically analyzed and proved to be precise and accurate.
Simultaneous Determination of Salmeterol Xinafoate and Fluticasone Propionate in Bulk Powder and Seritide Diskus using High Performance Liquid Chromatographic and Spectrophotometric Method
(Pharmaceutica Analytica Acta, 2012) Samir, Ahmed; Salem, Hesham; Abdelkawy, Mohammad
Five methods were developed for simultaneous determination of Salmeterol xinafoate (SAM) and Fluticasone propionate (FLU) without previous separation. In the first method (HPLC), a reversed-phase column and a mobile phase of acetonitrile: methanol (80:20 v/v) at 0.5 mLmin-1 flow rate was used to separate both drugs and UV detection at 220 nm. Linearity was obtained in concentration ranges of 50-500 µgmL-1 for Salmeterol xinafoate Fluticasone propionate. In the second method both drugs were determined using first derivative UV spectrophotometry, with zero crossing measurement at 352 and 269.5 nm for Salmeterol xinafoate and Fluticasone propionate, respectively. The third method depends on first derivative of the ratios spectra by measurements of the amplitudes at 334 and 337.5 nm for Salmeterol xinafoate and at 225 and 231.5 nm for Fluticasone propionate. Calibration graphs were established in the range of 4-28 µgmL-1 for both Salmeterol xinafoate and Fluticasone propionate. The fourth one depend on isosbestic point at 237.5 nm, while the content of Salmeterol xinafoate was determined by measuring the absolute value of the ultraviolet curves at 343 nm, without interference from Fluticasone propionate. All the proposed methods were extensively validated. They have the advantage of being economic and time saving. All the described methods can be readily utilized for the analysis of pharmaceutical formulations. The results obtained by adopting the proposed methods were statistically analyzed and compared with those obtained by official methods.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
(Elsevier, 5/21/2014) Lotfya, Hayam M.; Salehb, Sarah S.; Hassana, Nagiba Y; Salem, Hesham
This work represents the application of the isosbestic points present in different absorption spectra. Three novel spectrophotometric methods were developed, the first method is the absorption subtraction method (AS) utilizing the isosbestic point in zero-order absorption spectra; the second method is the amplitude modulation method (AM) utilizing the isosbestic point in ratio spectra; and third method is the amplitude summation method (A-Sum) utilizing the isosbestic point in derivative spectra. The three methods were applied for the analysis of the ternary mixture of chloramphenicol (CHL), dexamethasone sodium phosphate (DXM) and tetryzoline hydrochloride (TZH) in eye drops in the presence of benzalkonium chloride as a preservative. The components at the isosbestic point were determined using the corresponding unified regression equation at this point with no need for a complementary method. The obtained results were statistically compared to each other and to that of the developed PLS model. The specificity of the developed methods was investigated by analyzing laboratory prepared mixtures and the combined dosage form. The methods were validated as per ICH guidelines where accuracy, repeatability, inter-day precision and robustness were found to be within the acceptable limits. The results obtained from the proposed methods were statistically compared with official ones where no significant difference was observed.
Stability Indicating Spectrophotometric and Chemometric Methods for Determination of Aripiprazole in Presence of its Degradation Products, A Comparative Study
(Taylor & Francis, 2019) M. El-Maraghy, Christine; Salem, Hesham; M. Amer, Sawsan; Nebsen, Marianne
Simple, accurate, selective and validated stability indicating UV spectrophotometric univariate and multivariate methods were developed for determination of Aripiprazole in presence of its alkaline and oxidative degradation products. The developed univariate methods; derivative ratio spectra-zero crossing, successive derivatives of ratio spectra and mean centering of ratio spectra. The first one used the amplitude of the first derivative ratio signals at 303.0 nm, the second method depended on the successive derivative of ratio spectra in two steps and measuring the absorbance of Aripiprazole at 281.0 nm and the third one measured the mean centered values oat 294.0 nm. Two chemometric multivariate methods were applied; principal component regression (PCR) and partial least-squares regression (PLS). The selectivity of the proposed methods was confirmed using laboratory-prepared mixtures. The obtained results were statistically compared with those obtained with the manufacturer HPLC method, showing no significant difference with in accuracy and precision. These methods could be applied as stability indicating methods for the determination of Aripiprazole in presence of its degradation products, in bulk powder or in pharmaceutical formulations.
Validated HPLC Method for Simultaneous Determination of Aripiprazole and Co-Administered Clonazepam in Spiked Human Plasma
(Journal of Pharmaceutical and Applied Chemistry An International Journal, 2017) M. El-Maraghy, Christine; Salem, Hesham; M. Amer, Sawsan; Nebsen, Marianne
A sensitive and selective high performance liquid chromatographic method was developed and validated for the simultaneous quantification of Aripiprazole and co-administered Clonazepam in spiked human plasma. Aripiprazole, Clonazepam and the internal standard Citalopram were extracted from plasma and analyzed on a reversed-phase C18 column using a mobile phase consisting of acetonitrile and 0.05M potassium dihydrogen orthophosphate (pH= 3.6) in a ratio of (40: 60, v/v). The ultraviolet (UV) detection was at 220 nm. The method was linear over concentration range (20- 1000 ng mL-1 ) for both drugs. The method is very simple and allows obtaining a very good recovery of the analytes.