Browsing by Author "Salem H."

Now showing 1 - 20 of 26

Application of three novel spectrophotometric methods manipulating ratio spectra for resolving a pharmaceutical mixture of Chlorphenoxamine hydrochloride and Caffeine
(2013) Mohsen A.M.; Lotfy H.M.; Badawey A.M.; Salem H.; Elkhateeb S.Z.; Analytical Chemistry Department; MSA University; 6th October City; Giza; Egypt
Three spectrophotometric methods are presented for the determination of a binary mixture of Chlorphenoxaminehydrochloride (CPX) and Caffeine (CAF) in laboratory prepared mixture and pharmaceutical dosage form without prior separation. Method (I)is an extended ratio subtraction method (EXRSM) coupled with ratio subtraction method (RSM), which depends on subtraction of the plateau values from the ratio spectrum. Method (II)is a ratio difference spectrophotometric method (RDSM), which depends on the difference in value between two different wavelengths of the ratio spectrum. Method (III) is a mean centering of ratio spectra (MCR). Mathematical explanation of the three methods is illustrated. Calibration curves of the three methods are linear over the concentration ranges of 4-24 ?gml-1and 2-24 ?gml-1for CPX and CAF, respectively.The three methods proved to be simple, specific, accurate and precise. Solvent used is double distilled water. The three methods are validated as per the ICH guidelines where accuracy, precision, repeatability and robustness are found to be within the acceptable limits.
Column performance study of different variants of liquid chromatographic technique: An application on pharmaceutical ternary mixtures containing tetryzoline
(Oxford University Press, 2015) Salem H.; Hassan N.Y.; Lotfy H.M.; Saleh S.S.; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 6th October City; 11787; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini Street; Cairo; 11562; Egypt
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 ?m particle size), a RRLC column (C18 2.6 ?m particle size) and a UPLC column (C18 1.7 ?m 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 observed. � The Author 2014. Published by Oxford University Press.
A comparative study of different aspects of manipulating ratio spectra applied for ternary mixtures: Derivative spectrophotometry versus wavelet transform
(Elsevier, 2015) Salem H.; Lotfy H.M.; Hassan N.Y.; El-Zeiny M.B.; Saleh S.S.; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 11787 6th October City; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini Street; 11562 Cairo; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Modern University for Technology and Information (MTI); 12582 Al Hadaba Al Wosta; Cairo; Egypt
This work represents a comparative study of different aspects of manipulating ratio spectra, which are: double divisor ratio spectra derivative (DR-DD), area under curve of derivative ratio (DR-AUC) and its novel approach, namely area under the curve correction method (AUCCM) applied for overlapped spectra; successive derivative of ratio spectra (SDR) and continuous wavelet transform (CWT) methods. The proposed methods represent different aspects of manipulating ratio spectra of the ternary mixture of Ofloxacin (OFX), Prednisolone acetate (PA) and Tetryzoline HCl (TZH) combined in eye drops in the presence of benzalkonium chloride as a preservative. The proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the reported HPLC method, showing no significant difference with respect to accuracy and precision.� 2014 Elsevier B.V. All rights reserved.
A comparative study of novel spectrophotometric methods based on isosbestic points; Application on a pharmaceutical ternary mixture
(2014) Lotfy H.M.; Saleh S.S.; Hassan N.Y.; Salem H.; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini Street; 11562 Cairo; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 11787 6th October City; Egypt
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. � 2014 Elsevier B.V. All rights reserved.
A comparative study of progressive versus successive spectrophotometric resolution techniques applied for pharmaceutical ternary mixtures
(Elsevier, 2014) Saleh S.S.; Lotfy H.M.; Hassan N.Y.; Salem H.; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 11787 6th October City; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini Street; 11562 Cairo; Egypt
This work represents a comparative study of a novel progressive spectrophotometric resolution technique namely, amplitude center method (ACM), versus the well-established successive spectrophotometric resolution techniques namely; successive derivative subtraction (SDS); successive derivative of ratio spectra (SDR) and mean centering of ratio spectra (MCR). All the proposed spectrophotometric techniques consist of several consecutive steps utilizing ratio and/or derivative spectra. The novel amplitude center method (ACM) can be used for the determination of ternary mixtures using single divisor where the concentrations of the components are determined through progressive manipulation performed on the same ratio spectrum. Those 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 proposed methods were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical formulation containing the cited drugs. The proposed methods were validated according to the ICH guidelines. A comparative study was conducted between those methods regarding simplicity, limitation and sensitivity. The obtained results were statistically compared with those obtained from the official BP methods, showing no significant difference with respect to accuracy and precision. � 2014 Elsevier B.V. All rights reserved.
Comparative study of reversed-phase high-performance liquid chromatography versus thin-layer chromatography-densitometry for determination of Citicoline sodium in presence of its alkaline degradation products
(Akademiai Kiado Rt., 2015) Mahmoud O.A.; Hegazy M.A.; Salem H.; Moustafa A.A.; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); October City; 11787; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini Street; Cairo; 11562; Egypt
Simple, sensitive, selective, and precise stability-indicating thin-layer chromatography (TLC)-densitometric and reversed-phase high-performance liquid chromatography (RP-HPLC) methods were developed and validated for the determination of citicoline sodium (CT) in the presence of its alkaline degradation products (CT Deg.) and in pharmaceutical oral solution. TLC-densitometry employs aluminum TLC plates precoated with silica gel 60 F254 as the stationary phase and ammonia-ethyl acetate-triethylamine (6:3.5:0.5, v/v) as the mobile phase to give compact spots for citicoline sodium (RF = 0.35) and its degradation product (RF = 0.1); the chromatogram was scanned at 272 nm. RP-HPLC utilizes a C18 column and a mobile phase consisting of methanol-water-acetic acid (60:40:0.1, v/v); the pH level was adjusted to 4 using 0.1% orthophosphoric acid, at a flow rate of 1 mL min-1 for the separation of citicoline sodium (tR = 1.801) and its degradation product (tR = 3.422). Quantitation was achieved by ultraviolet (UV) detection at 272 nm. Citicoline sodium was exposed to alkaline hydrolysis, and a comparative study was carried out to show the advantages of the proposed chromatographic methods in determination of citicoline sodium in the presence of its alkaline degradation products. The chromatographic methods were developed and validated as per the International Conference on Harmonization guidelines. As the methods could effectively separate the drug from their degradation products, these techniques can be employed as stability-indicating methods that have been successively applied to pharmaceutical formulations without interference from the excipients. � Akad�miai Kiad�, Budapest.
A comparative study of smart spectrophotometric methods for simultaneous determination of a skeletal muscle relaxant and an analgesic in combined dosage form
(Elsevier, 2015) Salem H.; Mohamed D.; Pharmaceutical Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts; October City; 11787 6; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Helwan University; Ein Helwan; Cairo; 11795; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Deraya University; Cairo; 14511; Egypt
Six simple, specific, accurate and precise spectrophotometric methods were developed and validated for the simultaneous determination of the analgesic drug; paracetamol (PARA) and the skeletal muscle relaxant; dantrolene sodium (DANT). Three methods are manipulating ratio spectra namely; ratio difference (RD), ratio subtraction (RS) and mean centering (MC). The other three methods are utilizing the isoabsorptive point either at zero order namely; absorbance ratio (AR) and absorbance subtraction (AS) or at ratio spectrum namely; amplitude modulation (AM). The proposed spectrophotometric procedures do not require any preliminary separation step. The accuracy, precision and linearity ranges of the proposed methods were determined. The selectivity of the developed methods was investigated by analyzing laboratory prepared mixtures of the drugs and their combined dosage form. Standard deviation values are less than 1.5 in the assay of raw materials and capsules. The obtained results were statistically compared with each other and with those of reported spectrophotometric ones. The comparison showed that there is no significant difference between the proposed methods and the reported methods regarding both accuracy and precision. � 2015 Elsevier B.V. All rights reserved.
Computation of geometric representation of novel spectrophotometric methods used for the analysis of minor components in pharmaceutical preparations
(Elsevier, 2015) Lotfy H.M.; Saleh S.S.; Hassan N.Y.; Salem H.; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini; Cairo; 11562; Egypt; Pharmaceutical Chemistry Department; Faculty of Pharmaceutical Sciences and Pharmaceutical Industries; Future University in Egypt (FUE); Cairo; 12311; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 6th October; 11787; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Deraya University; Minia; Egypt
Novel spectrophotometric methods were applied for the determination of the minor component tetryzoline HCl (TZH) in its ternary mixture with ofloxacin (OFX) and prednisolone acetate (PA) in the ratio of (1:5:7.5), and in its binary mixture with sodium cromoglicate (SCG) in the ratio of (1:80). The novel spectrophotometric methods determined the minor component (TZH) successfully in the two selected mixtures by computing the geometrical relationship of either standard addition or subtraction. The novel spectrophotometric methods are: geometrical amplitude modulation (GAM), geometrical induced amplitude modulation (GIAM), ratio H-point standard addition method (RHPSAM) and compensated area under the curve (CAUC). The proposed methods were successfully applied for the determination of the minor component TZH below its concentration range. 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. No difference was observed between the obtained results when compared to the reported HPLC method, which proved that the developed methods could be alternative to HPLC techniques in quality control laboratories. � 2015 Elsevier B.V. All rights reserved.
Design, optimization, and validation of thin-layer chromatography-densitometry and chemometry-assisted spectrophotometry: A comparative study applied on quaternary mixture
(Akademiai Kiado Rt., 2015) Salem H.; Hassan N.Y.; Lotfy H.M.; Saleh S.S.; Department of Analytical Chemistry; Faculty of Pharmacy; Deraya University; Minia; Egypt; Department of Analytical Chemistry; Faculty of Pharmacy; Cairo University; Kasr-El Aini Street; Cairo; 11562; Egypt; Department of Pharmaceutical Chemistry; Faculty of Pharmaceutical Sciences and Pharmaceutical Industries; Future University in Egypt; Cairo; 12311; Egypt; Department of Analytical Chemistry; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); October City; 11787 6th; Egypt
This work presents a comparative study on the development and validation of two analytical techniques applied for the simultaneous determination of hydrocortisone acetate (HCA), fusidic acid (FSA), methyl paraben (MPB), and propyl paraben (PPB) formulated as a topical cream. The first technique was thin-layer chromatography (TLC)-densitometric method, which was developed by separating the four components on silica gel 60 F254 using methylene chloride-methanol-benzene in the ratio of 10:2:5, v/v, as the developing system, followed by densitometric measurement of the bands at 240 nm. The second technique was the chemometric method using two models: principle component regression model (PCR) and partial least squares (PLS). The suggested techniques were validated in compliance with the International Conference on Harmonization (ICH) guidelines and were successfully applied for the determination of the quaternary mixtures as prepared synthetically in laboratory and in the commercial topical pharmaceutical formulation. Akadmiai Kiad, Budapest.
Determination of fluoroquinolone antibiotics in industrial wastewater by high-pressure liquid chromatography and thin-layer chromatography-densitometric methods
(Akademiai Kiado Rt., 2014) Khattab F.I.; Salem H.; Riad S.M.; Elbalkiny H.T.; Cairo University; Analytical Chemistry Department; Faculty of Pharmacy; Kasr-El Aini Street; 11562 Cairo; Egypt; October University for Modern Sciences and Arts (MSA); Analytical Chemistry Department; Faculty of Pharmacy; 11787 6th October City; Egypt
Two methods were described for the simultaneous determination of ciprofloxacin HCl (CIP) and moxifloxacin HCl (MOX) in their binary mixture present in industrial wastewater. A solid-phase extraction procedure (SPE) based on retention on HLB OASIS cartridges and elution with a mixture of methanol-water in acidic medium was preformed, and then both fluoroquinolones were separated using two chromatographic methods. The first method was based on high-performance liquid chromatographic separation of the two drugs on reversed-phase Zorbax C18 column. The mobile phase consisted of monobasic potassium phosphate (50 mM, pH 2.5, adjusted with phosphoric acid) and acetonitrile (80:20, v/v). Flow rate was 1 mL min-1. Quantitation was achieved with ultraviolet (UV) detection at 278 nm. Linearity was found to be over the concentration range of 1-50 ?g mL-1 for both CIP and MOX. The second method was based on the thin-layer chromatographic (TLC) separation of the two drugs followed by densitometric measurements of their bands at 278 nm. The separation was carried out on silica gel 60 F254 plates, using methanol, ammonia, and methylene chloride (55:35:20, v/v) as a developing system. The linearity was found to be in the range of 0.25-2.5 ?g band -1 for both CIP and MOX. Both methods were optimized and validated as per International Conference on Harmonization (ICH) guidelines. Separation was developed on spiked water samples and checked on process wastewaters of industrial origin after SPE sample pretreatment.
Determination of metoprolol and felodipine in binary mixture using chemometric-assisted spectrophotometric and high-performance liquid chromatographic-UV methods
(Science Publications, 2007) Salem H.; Abdallah O.M.; Analytical Chemistry Department; Faculty of Pharmacy; Minia University; Minia; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Al-Azhar University; Cairo; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; MSA University; Cairo; Egypt
Four methods were developed for simultaneous determination of metoprolol and felodipine without previous separation. In the first method both drugs were determined using first derivative UV spectrophotometry, with zero crossing measurement at 222 and 235 nm for metoprolol and felodipine, respectively. The second method depends on first derivative of the ratios spectra by measurements of the amplitudes at 250.1 nm for metoprolol and 224.3 nm for felodipine. Calibration graphs are established in the range of 20-150 ?g/ml and 10-60 ?g/ml for metoprolol and felodipine, respectively. The third method describes the use of multivariate spectrophotometric calibration for the simultaneous determination of the analyzed binary mixture where the resolution is accomplished by using partial least squares (PLS) regression analysis. Although the components show high degree of spectral overlap, they are simultaneously determined with high accuracy and without interference of pharmaceutical dosage form excipients. A comparison with the related multivariate method of classicial least squares (CLS) analysis is done showing less relative results due to severe spectral overlap of the studied drugs. In the fourth method (HPLC), a reversed-phase column and a mobile phase of methanol:water:acetonitrile (70:22:8 v/v/v/) at 0.9 ml/ min flow rate is used to separate both drugs and UV detection at 260 nm. Good linearities are obtained in concentration range of 0.15-15 ?g/ml for metoprolol and 0.03-5 ?g/ml for felodipine. All the proposed methods are 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 fourth method (HPLC) is successfully applied for the analysis of both drugs in human serum samples. The results obtained by adopting the proposed methods are statistically analyzed and compared with those obtained by reported methods. � 2007 Science Publications.
Development and validation of impurity-profiling UPLC method for the determination of sodium cromoglicate and tetryzoline hydrochloride: Application on rabbit aqueous humor
(Elsevier, 2015) Lotfy H.M.; Saleh S.S.; Hassan N.Y.; Salem H.; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini; Cairo; 11562; Egypt; Pharmaceutical Chemistry department; Faculty of Pharmaceutical sciences and Pharmaceutical industries; Future University in Egypt (FUE); Cairo; 12311; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 6th October; 11787; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Deraya University; Minia; Egypt
Sodium cromoglicate (SCG), antihistaminic agent, and tetryzoline hydrochloride (TZH), a sympathomimetic agent, are formulated together as an ophthalmic preparation. An ultra-performance liquid chromatographic method with UV detection (UPLC-UV) was developed and validated for the quantitative determination of SCG and TZH in rabbit aqueous humor. Due to the instability of both SCG and TZH under alkaline conditions, the UPLC method was applied for their determination in the presence of their possible degradation impurities. The separation was performed using C18 column (1.7?m particle size) and isocratic elution system with methanol: 1% o-phosphoric acid (65: 35, v/v). The optimum flow rate was 0.5ml/min and the detection was done at 230nm. The suggested method was validated in compliance with the ICH guidelines and was successfully applied for determination of sodium cromoglicate (SCG) and tetryzoline HCl (TZH) as prepared synthetically in laboratory mixtures, and in the presence of their alkali-induced degradation impurities. The suggested method was effectively applied the determination of spiked rabbit aqueous humor samples as well as commercial pharmaceutical formulation. � 2015 Elsevier B.V.
Development and validation of simultaneous spectrophotometric and TLC-spectrodensitometric methods for determination of beclomethasone dipropionate and salbutamol in combined dosage form
(Elsevier, 2014) Samir A.; Lotfy H.M.; Salem H.; Abdelkawy M.; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts; Egypt
Spectrophotometric and TLC-spectrodensitometric methods were developed and validated for the simultaneous determination of beclomethasone dipropionate (BEC) and salbutamol (SAL). The spectrophotometric methods include dual wavelength, ratio difference, constant center coupled with a novel method namely, spectrum subtraction and mean centering with mean percentage recoveries and RSD 99.72 � 1.07 and 99.70 � 1.12, 100.25 � 1.12 and 99.89 � 1.12, 99.66 � 1.85 and 99.19 � 1.32, 100.74 � 1.26 and 101.06 � 0.90 for BEC and SAL respectively. The TLC-spectrodensitometric method was based on separation of both drugs on TLC aluminum plates of silica gel 60 F254, using benzene: methanol: triethylamine (10:1.5:0.5 v/v/v) as a mobile phase, followed by densitometric measurements of their bands at 230 nm. The mean percentage recoveries and RSD were 99.07 � 1.25 and 101.35 � 1.50 for BEC and SAL respectively. The proposed methods were validated according to ICH guidelines and were applied for the simultaneous analysis of the cited drugs in synthetic mixtures and pharmaceutical preparation. The methods were found to be rapid, specific, precise and accurate and can be successfully applied for the routine analysis of BEC and SAL in their pharmaceutical formulation with no need for prior separation. The results obtained were statistically compared to each other and to that of the reported HPLC method. The statistical comparison showed that there is no significant difference regarding both accuracy and precision. � 2014 Elsevier B.V. All rights reserved.
Development of membrane electrodes for the specific determination of tetryzoline hydrochloride in presence of its degradation product in pharmaceutical formulations and biological fluids
(Center of Excellence in Electrochemistry, Univ. of Tehran, 2015) Hassan N.Y.; Lotfy H.M.; Saleh S.S.; Salem H.; Analytical Chemistry Department; Cairo University; Kasr�El Aini Street; Cairo; 11562; Egypt; Analytical Chemistry Department; Future University (FUE); New Cairo; 11835; Egypt; Analytical Chemistry Department; October University for Modern Sciences and Arts (MSA); 6th October City; 11787; Egypt; Analytical Chemistry Department; Deraya University; Minia; Egypt
Membrane selective electrodes were used to determine tetryzoline hydrochloride (TZH) in pure form, pharmaceutical preparations and in biological fluids. The membrane selective electrodes include construction of water insoluble ion-association complexes. The TZH ion exchangers were formed using tetraphenyl borate (TZH-TPB), phosphomolybdic acid (TZH-PMA) and phosphotungstic acid (TZH-PTA), in a plasticized PVC (polyvinyl chloride) matrix, using dibutyl phthalate (DBP) or dioctylphthalate (DOP) as a plasticizer. The performance characteristics of the developed sensors were evaluated according to IUPAC recommendations. The developed sensors showed good responses but the best electrochemical characteristics and selectivity coefficients were achieved with TZH-TPB sensor using DBP as a plasticizer, where the linear responses of TZH was found within the concentration ranges of 10?6 to 10?2 mol/L and Nernstian slope was calculated to be of 56.8 mV/ decade at 25 �C, over the pH range of 5�9. The suggested method was used to determine TZH in synthetic mixtures, pharmaceutical formulations and in presence of its alkali degradation product. The proposed sensors displayed useful analytical characteristics for the determination of TZH in biological fluids such as rabbit aqueous humor and human plasma. The later application can be used to detect oral TZH poisoning in children. The obtained results were statistically compared with the official method, showing no significant difference with respect to accuracy and precision. � 2015 The Authors.
Eutectic, monotectic and immiscibility systems of nimesulide with water-soluble carriers: Phase equilibria, solid-state characterisation and in-vivo/pharmacodynamic evaluation
(Blackwell Publishing Ltd, 2014) Abdelkader H.; Abdallah O.Y.; Salem H.; Alani A.W.G.; Alany R.G.; Department of Pharmaceutics; Faculty of Pharmacy; Minia University; Minia; Egypt; Department of Pharmaceutics; Faculty of Pharmacy; Alexandria University; Alexandria; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Science and Arts; Cairo; Egypt; Department of Pharmaceutical Sciences; College of Pharmacy; Oregon State University; Corvallis; OR; United States; School of Pharmacy and Chemistry; Kingston University London; Kingston upon Thames; United Kingdom; School of Pharmacy; University of Auckland; Auckland; New Zealand
Objectives The solid-state interactions of fused mixtures nimesulide (ND) with polyethylene glycol (PEG) 4000, urea or mannitol were studied through constructing thaw-melt phase equilibrium diagrams. Methods The solid-state characteristics were investigated using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Various types of interactions were identified such as the formation of a eutectic system of ND-PEG 4000, monotectic system of ND-urea and complete solid immiscibility of ND with mannitol. The effects of carrier concentrations on the equilibrium solubility and in-vitro dissolution characteristics were studied. Key findings Linear increases (R2 > 0.99) in the aqueous solubility of ND in various concentrations of PEG 4000 and urea were obtained, whereas mannitol did not exhibit any effect on the solubility of ND. Similar trends were obtained with the dissolution efficiency of the fused mixtures of ND with PEG 4000 and urea compared with the corresponding physical mixtures and untreated drug. The analgesic effects of untreated ND and the selected formulations were investigated by evaluating the drug's ability to inhibit the acetic acid-induced writhing response. Conclusions The analgesic effect of ND in a eutectic mixture with PEG 4000 and a monotectic mixture with urea was potentiated by 3.2 and 2.7-fold respectively compared with the untreated drug. � 2014 Royal Pharmaceutical Society.
Evaluating the efficiency of spectral resolution of univariate methods manipulating ratio spectra and comparing to multivariate methods: An application to ternary mixture in common cold preparation
(Elsevier B.V., 2015) Moustafa A.A.; Salem H.; Hegazy M.; Ali O.; Analytical Chemistry Department; Faculty of Pharmacy; Cairo University; Kasr-El Aini Street; Cairo; 11562; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; October University for Modern Sciences and Arts (MSA); 6th October City; 11787; Egypt; Analytical Chemistry Department; Faculty of Pharmacy; Deraya University; Cairo; 14511; Egypt
Simple, accurate, and selective methods have been developed and validated for simultaneous determination of a ternary mixture of Chlorpheniramine maleate (CPM), Pseudoephedrine HCl (PSE) and Ibuprofen (IBF), in tablet dosage form. Four univariate methods manipulating ratio spectra were applied, method A is the double divisor-ratio difference spectrophotometric method (DD-RD). Method B is double divisor-derivative ratio spectrophotometric method (DD-RD). Method C is derivative ratio spectrum-zero crossing method (DRZC), while method D is mean centering of ratio spectra (MCR). Two multivariate methods were also developed and validated, methods E and F are Principal Component Regression (PCR) and Partial Least Squares (PLSs). The proposed methods have the advantage of simultaneous determination of the mentioned drugs without prior separation steps. They were successfully applied to laboratory-prepared mixtures and to commercial pharmaceutical preparation without any interference from additives. The proposed methods were validated according to the ICH guidelines. The obtained results were statistically compared with the official methods where no significant difference was observed regarding both accuracy and precision. � 2014 Elsevier B.V. All rights reserved.
Ion selective membrane electrodes for determination of Citalopram Hydrobromide in drug product and in presence of its degradation products
(Center of Excellence in Electrochemistry, Univ. of Tehran, 2015) Nebsen M.; El-Maraghy C.M.; Salem H.; Amer S.M.; Analytical Chemistry department; Cairo University; Kasr-El Aini Street; Cairo; 11562; Egypt; Pharmaceutical Analytical Chemistry department; Heliopolis University; 3 Cairo Belbeis desert road; El-Horria; Cairo; 2834; Egypt; Analytical Chemistry department; October University for Modern Sciences and Arts (MSA); 6th October city; 11787; Egypt; Pharmaceutical Analytical Chemistry department; Deraya University; Minia; Egypt
This paper presents a comparative study between three sensors developed to determine Citalopram Hydrobromide (CT) in the presence of its alkaline hydrolysis and oxidation induced degradation products using different ion association complexes. Sensor 1 was fabricated using phosphomolybdic acid, Sensor 2 used phosphotungestic acid and sensor 3 used the sodium tetraphenyl borate. Linear responses of CT were obtained within the concentration ranges of 1�10?6 to 1�10?2 mol L-1 for sensor 1 and 2 and 1�10?5 to 1�10?2 mol L-1 for sensor 3 over the pH range of 3.0�6.0. The selectivity coefficients of the developed sensors indicated excellent selectivity for CT. The proposed sensors displayed useful analytical characteristics for the determination of CT in bulk powder, pharmaceutical formulation, and in the presence of its degradation products and thus could be used for stability-indicating methods. The method was validated according to ICH guidelines. Statistical comparison between the results from the proposed method and the results from the reference HPLC method showed no significant difference regarding accuracy and precision. � 2015 by CEE (Center of Excellence in Electrochemistry).
Ion-Selective membrane sensors for the determination of ciprofloxacin hydrochloride in water and pharmaceutical formulation
(Center of Excellence in Electrochemistry, Univ. of Tehran, 2014) Riad S.M.; Khattab F.I.; Salem H.; Elbalkiny H.T.; Analytical Chemistry Department; Cairo University; Kasr-El Aini Street; Cairo; 11562; Egypt; Analytical Chemistry Department; October University for Modern Sciences and Arts (MSA); 6th October City; 11787; Egypt
The construction and electrochemical response characteristics of six Ciprofloxacin-selective electrodes were investigated using precipitation based technique with sodium tetraphenyl borate (TPB), phosphomolybdate (PMA) and phosphotungstate (PTA); respectively upon using polyvinyl chloride (PVC) matrix and dibutyl phthalate (DBP) as a plasticizer. The resultant sensors have different forms, either as membrane electrodes (sensors 1, 3 and 5) or as coated wire electrodes (sensors 2, 4 and 6). Linear responses of CIP within the concentration ranges of 10?6 to 10?2 mol/L for sensors 1, 2 and 5 while for sensors 3 and 4, the linear responses were within the concentration ranges of 10?5 to 10?2 mol/L and for sensor 6 it shows linear responses within the concentration ranges of 10?7 to 10?2 mol/L. Nernstian slopes of 51.7, 50.7, 58.3, 57.7, 44 and 41.8 mV/decade were observed over the pH range of (5�9) for sensors 1, 2, 5 and 6 and over range of (5-7) for sensor 3 and 4 respectively. The selectivity coefficients of the developed sensors indicated excellent selectivity for CIP. The proposed sensors displayed useful analytical characteristics for the determination of CIP in water samples and pharmaceutical preparation. 2014 by CEE.
Ion-selective membrane sensors for the determination of tinidazole and clarithromycin in bulk powder and pharmaceutical formulation
(Center of Excellence in Electrochemistry, Univ. of Tehran, 2014) Riad S.M.; Rezk M.R.; Ahmed K.; Salem H.; Analytical Chemistry Department; Cairo University; Kasr El-Aini Street; Cairo; 11562; Egypt; Pharmaceutical and Analytical Chemistry Department; University for Modern Sciences and Arts; 6th of October city; Egypt; Pharmaceutical and Analytical Chemistry Department; Deraya University; Egypt
The construction and electrochemical response characteristics of three selective electrodes were investigated using precipitation based technique with phosphotungstate and phosphomolybdate; respectively upon using polyvinyl chloride (PVC) matrix and dioctyl phthalate (DOP) as a plasticizer. The resultant membrane sensors were tinidazole phosphotungestate (TND-PTA) electrode (sensors 1), tinidazole phosphomolybdate (TNDPMA) electrode (sensors 2) and clarithromycin phosphotungestate (CLR-PTA) electrode (sensors 3). Linear responses of TND and CLR within the concentration ranges of 10?6to 10?2mol/L for sensors 1, 2 and 3 were observed. Nernstian slopes of 58.3, 57.1 and 58.8 mV/decade were observed over the pH range of 3-7 for sensors 1and 2 and over range of 3-8 for sensor 3, respectively. The selectivity coefficients of the developed sensors indicated excellent selectivity for TND and CLR. The proposed sensors displayed useful analytical characteristics for the determination of TND and CLR in bulk powder and pharmaceutical formulation (Helicure. tablets). 2014 by CEE.
LC simultaneous determination of thioctic acid, benfotiamine and cyanocobalamin in thiotacid compound capsules
(2010) Salem H.; Analytical Chemistry Department; Faculty of Pharmacy; MSA University; Egypt
A simple, selective, sensitive, precise, simultaneous liquid chromatographic analysis of capsules containing thioctic acid, benfotiamine and cyanocobalamin was described. Good chromatographic separation was achieved using a Zorbax C18 (4.6 cm � 250 mm, 5 ?m) and a mobile phase consisting of acetonitrile-phosphate buffer pH 3.5 (15:85, v/v) at a flow rate of 0.9 mL min-1. The ultraviolet detector was set a wavelength of 280 nm. Thioctic acid, benfotiamine and cyanocobalamin were eluted at 2.869, 3.752 and 13.689 min, respectively. The linear ranges for thioctic acid, benfotiamine and cyanocobalamin were 30-180, 4-24 and 0.025-0.150 ?g mL-1, respectively. The recoveries of thioctic acid, benfotiamine and cyanocobalamine in pharmaceutical preparation were all greater than 98% and their relative standard deviations were less than 2.0%. The limits of detection were 2.57, 0.19 and 0.003 ?g mL-1 for thioctic acid, benfotiamine and cyanocobalamin, respectively. � 2010 Vieweg+Teubner Verlag | Springer Fachmedien Wiesbaden GmbH.