scholarly journals Spectrophotometric Stability-Indicating Methods for the Determination of Leflunomide in the Presence of Its Degradates

2006 ◽  
Vol 89 (6) ◽  
pp. 1524-1531 ◽  
Author(s):  
Samah S Abbas ◽  
Lories I Bebawy ◽  
Laila A Fattah ◽  
Heba H Refaat
Keyword(s):  
Dosage Forms ◽  
Derivative Spectrophotometry ◽  
Reaction Conditions ◽  
Pharmaceutical Dosage Forms ◽  
First Derivative ◽  
Beer's Law ◽  
First Derivative Spectrophotometry ◽  
Colored Product ◽  
Beer’S Law

Abstract Five simple and sensitive methods were developed for the determination of leflunomide (I) in the presence of its degradates 4-trifluoromethyl aniline (II) and 3-methyl-4-carboxy isoxazole (III). Method A was based on differential derivative spectrophotometry by measuring the △1D value at 279.5 nm. Beer's law was obeyed in the concentration range of 2.0020.00 μg/mL with mean percentage accuracy of 100.07 1.32. Method B depended on first-derivative spectrophotometry and measuring the amplitude at 253.4 nm. Beer's law was obeyed in the concentration range of 2.0016.00 μg/mL with mean percentage accuracy of 98.42 1.61. Method C was based on the reaction of degradate (II) with 2,6-dichloroquinone-4-chloroimide (Gibbs reagent). The colored product was measured at 469 nm. Method D depended on the reaction of degradate (II) with para-dimethyl aminocinnamaldehyde (p-DAC). The absorbance of the colored product was measured at 533.4 nm. Method E utilized 3-methyl-2-benzothiazolinone hydrazone in the presence of cerric ammonium sulfate with degradate (II). The green colored product was measured at 605.5 nm. The linearity range was 40.00-280.00, 2.40-24.00, and 30-250 μg/mL with mean percentage accuracy of 100.75 1.21, 100.13 1.45, and 99.74 1.39 for Methods CE, respectively. All variables were studied to optimize the reaction conditions. The proposed methods have been successfully applied to the analysis of leflunomide in pharmaceutical dosage forms and the results were statistically compared with that previously reported.

scholarly journals Determination of Two Antibacterial Binary Mixtures by Chemometrics-Assisted Spectrophotometry

2007 ◽  
Vol 90 (1) ◽  
pp. 128-141 ◽  
Author(s):  
Abd El-Maaboud I Mohamed ◽  
Osama H Abdelmageed ◽  
Ibrahim H Refaat
Keyword(s):  
Binary Mixtures ◽  
Colorimetric Method ◽  
Correlation Coefficients ◽  
Dosage Forms ◽  
Considerable Degree ◽  
Zero Crossing ◽  
First Derivative ◽  
Beer's Law ◽  
Beer’S Law

Abstract Simple chemometrics-assisted spectrophotometric methods are described for determination of 2 antibacterial binary mixtures. The mixtures are composed of norfloxacin in combination with tinidazole and erythromycin (as ethylsuccinate ester or stearate salt) in combination with trimethoprim. The normal UV absorption spectra of each pair of drugs in the studied mixtures, in the range of 200-400 nm, showed a considerable degree of spectral overlapping: 77.5% for the norfloxacintinidazole mixture and 84.3% for the erythromycintrimethoprim mixture. Resolution of the norfloxacintinidazole mixture and trimethoprim in the presence of erythromycin was accomplished successfully by using zero-crossing first derivative (1D), classical least-squares (CLS) regression analysis, and principal component regression (PCR) analysis methods. In addition, an alternative simple and accurate colorimetric method was developed for the determination of erythromycin in the presence of trimethoprim using 2,4-dinitrophenylhydrazine. All variables affecting the development of the colored chromogen were studied and optimized, and the product was measured at 526-529 and 538-542 nm for erythromycin stearate and erythromycin ethylsuccinate, respectively. For zero-crossing, first derivative technique Beer’s law was obeyed in the general concentration range of 250 μg/mL for norfloxacin, tinidazole, and trimethoprim with good correlation coefficients (0.9994-0.9996). Overall limits of detection (LOD) and quantification (LOQ) ranged from 0.59 to 2.81 and 1.96 to 9.33 μg/mL, respectively. The obtained results from CLS and PCR were compared with those obtained from a 1D spectrophotometric method. With the exception of erythromycin, overall recoveries in the average range of 97.33-103.0% were obtained with a considerable degree of accuracy when the suggested methods were applied to analysis of synthetic binary mixtures, some commercial dosage forms such as tablets and oral suspension without interference from the commonly encountered excipients and additives. For the colorimetric method, Beer's law was obeyed in the general concentration range of 7.21-28.84 μg/mL erythromycin with good correlation coefficients (0.9980-0.9996). Overall LOD and LOQ ranged from 0.73 to 1.65 and 2.43-5.49 μg/mL, respectively. Erythromycin derivatives were determined in the commercial dosage form, without interference from trimethoprim-encountered excipients and additives. The obtained results, with both chemometric and colorimetric methods, have been compared with those obtained from reported methods, and proper F- and t-values were observed, indicating no significant difference between the results of the suggested methods and reported method(s). The good percentage recoveries and proper statistical data obtained proved the efficiency of the proposed procedures for the determination of the studied drugs in their binary mixtures as well as in the commercial dosage forms with quite satisfactory precision.

scholarly journals Development and validation of spectrophotometric methods for determination of ceftazidime in pharmaceutical dosage forms

2008 ◽  
Vol 58 (3) ◽  
pp. 275-285 ◽  
Author(s):  
Basavaraj Hiremath ◽  
Bennikallu Mruthyunjayaswamy
Keyword(s):  
Pharmaceutical Formulations ◽  
Dosage Forms ◽  
Color Intensity ◽  
Reaction Conditions ◽  
Pharmaceutical Dosage Forms ◽  
Spectrophotometric Methods ◽  
Colored Product ◽  
Ethylenediamine Dihydrochloride ◽  
Development And Validation

Development and validation of spectrophotometric methods for determination of ceftazidime in pharmaceutical dosage formsTwo spectrophotometric methods for the determination of ceftazidime (CFZM) in either pure form or in its pharmaceutical formulations are described. The first method is based on the reaction of 3-methylbenzothiazolin-2-one hydrazone (MBTH) with ceftazidime in the presence of ferric chloride in acidic medium. The resulting blue complex absorbs at λmax628 nm. The second method describes the reaction between the diazotized drug andN-(1-naphthyl)ethylenediamine dihydrochloride (NEDA) to yield a purple colored product with λmaxat 567 nm. The reaction conditions were optimized to obtain maximum color intensity. The absorbance was found to increase linearly with increasing the concentration of CFZM; the systems obeyed the Beer's law in the range 2-10 and 10-50 μg mL-1for MBTH and NEDA methods, resp.LOD, LOQand correlation coefficient values were 0.15, 0.79 and 0.50, 2.61. No interference was observed from common excipients present in pharmaceutical formulations. The proposed methods are simple, sensitive, accurate and suitable for quality control applications.

Spectrophotometric Method for Determination of Cephalexin in Its Dosage Forms

1992 ◽  
Vol 75 (6) ◽  
pp. 994-998 ◽  
Author(s):  
Ila T Patel ◽  
Muljibhai B Devani ◽  
Tushar M Patel
Keyword(s):  
Spectrophotometric Method ◽  
Dosage Forms ◽  
Oral Suspension ◽  
Specific Method ◽  
Reaction Conditions ◽  
Beer's Law ◽  
Beer’S Law ◽  
Official Procedure

Abstract A simple, rapid, and specific method was developed for determination of cephalexin and its dosage forms. The method is based on the reaction of cephalexin with acetylacetone-formaldehyde reagent to give a yellow chromophore measurable at 400 nm. The color is stable for 3 h. Beer's law is valid within a concentration range of 10-100 μg/mL for cephalexin. All variables were studied to optimize the reaction conditions. The method is specific for amino β-lactam antibiotics. Non-amino β-lactam antibiotics do not interfere. No interference was observed in the presence of common pharmaceutical adjuvants. The validity of the method was tested by analyzing cephalexin tablets, capsules, and oral suspension. Good recoveries were obtained for these preparations. The results were comparable with those obtained by the official procedure

scholarly journals Safety method, Spectrophotometric Determination of Sulfamethaxazole drug in bulk and Pharmaceutical Preparations

2010 ◽  
Vol 7 (1) ◽  
pp. 607-613 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Acidic Medium ◽  
Pharmaceutical Preparations ◽  
Color Stability ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Reaction Conditions ◽  
Pharmaceutical Dosage Forms ◽  
Stability Period ◽  
Orange Color

A simple, cheap, fast, accurate, Safety and sensitive spectrophotometric method for the determination of sulfamethaxazole (SFMx), in pure form and pharmaceutical dosage forms. has been described The Method is based on the diazotization of the drug by sodium nitrite in acidic medium at 5Cº followed by coupling with salbutamol sulphate (SBS) drug to form orange color the product was stabilized and measured at 452 nm Beer’s law is obeyed in the concentration range of 2.5-87.5 ?g ml-1 with molar absorptivity of 2.5x104 L mole-1 cm-1. All variables including the reagent concentration, reaction time, color stability period, and sulfamethaxazole /salbutamol ratio were studied in order to optimize the reaction conditions. No interferences were observed Results of analysis were validated statistically and by recovery studies. These methods are successfully employed for the determination of sulfamethaxazole in some pharmaceutical preparations.. The developed method is easy to use and accurate for routine studies relative to HPLC and other techniques.

scholarly journals Liquid Chromatographic and Spectrophotometric Determination of Diflucortolone Valerate and Isoconazole Nitrate in Creams

2011 ◽  
Vol 94 (1) ◽  
pp. 128-135 ◽  
Author(s):  
Elif Karacan ◽  
Mehmet Gokhan Çaġlayan ◽  
İsmail Murat Palabiyik ◽  
Feyyaz Onur
Keyword(s):  
Principal Component Regression ◽  
Principal Component ◽  
Derivative Spectrophotometry ◽  
Data Matrix ◽  
Concentration Data ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
First Derivative Spectrophotometry ◽  
Liquid Chromatographic

Abstract A new RP-LC method and two new spectrophotometric methods, principal component regression (PCR) and first derivative spectrophotometry, are proposed for simultaneous determination of diflucortolone valerate (DIF) and isoconazole nitrate (ISO) in cream formulations. An isocratic system consisting of an ACE® C18 column and a mobile phase composed of methanol–water (95+5, v/v) was used for the optimal chromatographic separation. In PCR, the concentration data matrix was prepared by using synthetic mixtures containing these drugs in methanol–water (3+1, v/v). The absorbance data matrix corresponding to the concentration data matrix was obtained by measuring the absorbances at 29 wavelengths in the range of 242–298 nm for DIF and ISO in the zero-order spectra of their combinations. In first derivative spectrophotometry, dA/dλ values were measured at 247.8 nm for DIF and at 240.2 nm for ISO in first derivative spectra of the solution of DIF and ISO in methanol–water (3+1, v/v). The linear ranges were 4.00–48.0 μg/mL for DIF and 50.0–400 μg/mL for ISO in the LC method, and 2.40–40.0 μg/mL for DIF and 60.0–260 μg/mL for ISO in the PCR and first derivative spectrophotometric methods. These methods were validated by analyzing synthetic mixtures. These three methods were successfully applied to two pharmaceutical cream preparations.

scholarly journals Use of N, N-diethyl-p-phenylenediamine sulphate for the spectrophotometric determination of some phenolic and amine drugs

2010 ◽  
Vol 60 (2) ◽  
pp. 217-227 ◽  
Author(s):  
Padmarajaiah Nagaraja ◽  
Ashwinee Shrestha ◽  
Anantharaman Shivakumar ◽  
Avinash Gowda
Keyword(s):  
Spectrophotometric Determination ◽  
Correlation Coefficients ◽  
Dosage Forms ◽  
Pharmaceutical Dosage Forms ◽  
Variable Parameters ◽  
Spectrophotometric Methods ◽  
Linear Relationships ◽  
Colored Product ◽  
And Performance

Use ofN, N-diethyl-p-phenylenediamine sulphate for the spectrophotometric determination of some phenolic and amine drugsSpectrophotometric methods are proposed for the determination of drugs containing a phenol group [salbutamol sulphate (SLB), ritodrine hydrochloride (RTD), isoxsuprine hydrochloride (IXP)] and drugs containing an aromatic amine group [dapsone hydrochloride (DAP), sulfamethoxazole (SFM), and sulfadiazine (SFD)] in pharmaceutical dosage forms. The methods are based on coupling ofN, N-diethyl-p-phenylenediamine sulphate with the drugs in the presence of KIO4to give a green colored product (λmaxat 670 nm) and a red colored product (λmaxat 550 nm), respectively. Linear relationships with good correlation coefficients (0.9986-0.9996) were found between absorbance and the corresponding concentration of drugs in the range 1-7, 2-22, 1-17, 1.5-12, 2-25, and 2-21 μg mL-1for SLB, RTD, IXP, DAP, SFM and SFD, respectively. Variable parameters such as temperature, reaction time and concentration of the reactants have been analyzed and optimized. The RSD of intra-day and inter-day studies was in the range of 0.2-1.0 and 0.4-1.0%, respectively. No interference was observed from common pharmaceutical adjuvants. The reliability and performance of the proposed methods was validated statistically; the percentage recovery ranged from 99.5 ± 0.1 to 99.9 ± 0.3%. Limits of detection were 0.14, 0.21, 0.51, 0.44, 0.33 and 0.37 μg mL-1for SLB, RTD, IXP, DAP, SFM, and SFD, respectively.

Colorimetric Determination of Sympathomimetic Amines Methyldopa and Noradrenaline

1985 ◽  
Vol 68 (1) ◽  
pp. 91-95
Author(s):  
Mohamed I Walash ◽  
Abed Abou Ouf ◽  
Fatma B Salem
Keyword(s):  
Alkaline Solution ◽  
Dosage Forms ◽  
Colorimetric Determination ◽  
Sympathomimetic Amines ◽  
Chromogenic Reagent ◽  
Beer's Law ◽  
Beer’S Law ◽  
Orange Color

Abstract The chromogenic reagent p-dimethylaminocinnamaldehyde (PDAC) is introduced for the determination of the sympathomimetic amines methyldopa and noradrenaline. The method is based on measurement of the orange color developed when the alkaline solution of methyldopa and noradrenaline is allowed to react with PDAC at pH 5.0. The color developed obeys Beer's law in the concentration range 0.1-1.5 mL of 2 x 103M solution of noradrenaline and methyldopa. The results are compared with those obtained with another chromogenic reagent, pdimethylaminobenzaldehyde (PDAB). Determinations on dosage forms of the drugs, using PDAC and PDAB reagents, agreed well with results of determinations by official pharmacopoeia! methods.

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