scholarly journals Pyrocatechol Violet in Pharmaceutical Analysis Part II. A Spectrophotometric Method for the Determination of Paracetamol in Pure and in Pharmaceutical Dosage Forms

2001 ◽  
Vol 69 (2) ◽  
pp. 179-188 ◽  
Author(s):  
Alaa Amin

A spectrophotometric method for the selective determination of paracetamol based on its reaction with pyrochatechol violet under basic conditions to form an ion-pair complex is described. The absorption maximum of the coloured ion-pair formed is observed at 652 nm and the molar absorptivity is 4.54 x10-3l mol-1 cm-1. Beer's law is obeyed over the concentration range 0.5-34.0 μg ml-1, while that obtained using Ringbom method is in the range 3.5 -32.0 μg ml-1. There is no interference from common additives, excipients and commercial drugs present in their formulations suggesting a highly selective procedure compared with others. Statistical analysis of the obtained results showed that there is, no significant difference and absence of any systematic error in the method compared with the official one. The method is simple, rapid and convenient and was applied successfully to the determination of paracetamol in pure and in its dosage forms compared with the official method.

2011 ◽  
Vol 17 (3) ◽  
pp. 259-267 ◽  
Author(s):  
Nagaraju Rajendraprasad ◽  
Kanakapura Basavaiahf ◽  
Basavaiah Vinay

Quetiapine fumarate (QTF) is an antipsychotic drug belonging to the benzisoxazole derivatives indicated for the treatment of schizophrenia. A sensitive and selective method based on dichloromethane-extractable ion-pair of QTF with calmagite (CGT), which exhibited an absorption maximum at 490 nm, is described. At this wavelength, Beer?s law is obeyed over the concentration range of 3.0 - 30.0 ?g ml-1. The apparent molar absorptivity, limit of detection (LOD) and quantitation (LOQ) values are 1.32 ? 104 l mol-1 cm-1, 0.27 and 0.81 ?g ml-1 respectively. The reaction is extremely rapid at room temperature and the absorbance values remain unchanged upto 19 h. The precision results, expressed as intra-day and inter-day relative standard deviation values, are satisfactory (RSD ? 2.2%). The accuracy is satisfactory as well (RE ? 2.44%). The method was successfully applied to the determination of QTF in pharmaceuticals and spiked human urine with satisfactory results. No interference was observed from common pharmaceutical adjuvants in tablets. Statistical comparison of the results with official method showed an excellent agreement and indicated no significant difference in precision.


Author(s):  
RAGAA EL-SHEIKH ◽  
AHLAM E. ABD ELLATEIF ◽  
ESRAA AKMAL ◽  
AYMAN A. GOUDA

Objective: Three sensitive, simple, precise, reproducible, and validated spectrophotometric methods have been developed for the determination of anti-psychotic drug (asenapine maleate) in pure and pharmaceutical dosage forms. Methods: The methods are based on the formation of yellow-colored ion-pair complex between asenapine maleate and three acid dyes, namely, bromocresol purple (BCP), bromophenol blue (BPB) and bromothymol blue (BTB) with absorption maxima at 410, 414 and 416 nm, respectively. Several parameters such as pH, buffer type and volume, reagent volume, the sequence of addition and effect of extracting solvent were optimized. Results: Under the optimum experimental conditions, beer’s law is obeyed over the concentration ranges of 1.0–20, 1.0–14, and 1.0-16 μg/ml for BCP, BPB and BTB, respectively, with good correlation coefficients (0.9994-0.9998). The apparent molar absorptivity and Sandell’s sensitivity values are reported for all methods. The limit of detection (LOD) and the limit of quantification (LOQ) values are found to be 0.27, 0.30, and 0.25 μg/ml and 0.90, 1.0, and 0.83 μg/ml for BCP, BPB and BTB, respectively. The stoichiometric ratio of the formed ion-pair complexes was found to be 1:1 (drug: reagent) for all methods, as deduced by Job's method of continuous variation. Conclusion: The proposed methods were successfully applied for the determination of asenapine maleate in pharmaceutical formulations with good accuracy and precision. Statistical comparison of the results was performed using Student's t-test and variance ratio F-test at the 95% confidence level and there was no significant difference between the reported and proposed methods regarding accuracy and precision. Further, the validity of the proposed methods was confirmed by recovery studies via standard addition technique in accordance with ICH guidelines.


2016 ◽  
Vol 2 (1) ◽  
pp. 28 ◽  
Author(s):  
Zeeshan Masood ◽  
Muhammad Tayyab Ansari ◽  
Sharjeel Adnan ◽  
Muhammad Asad ◽  
Muhammad Farooq ◽  
...  

A rapid, simple and sensitive spectrophotometric method has been developed for the determination of metronidazole in pharmaceutical pure and dosage forms. The method depends on alkaline hydrolysis of metronidazole releases the nitro group as nitrite ion and yielded nitrite ions can be used to give a colored complex that absorbs maximally at 505 nm. Beer’s law is obeyed in the concentration ranges 9-100 mg/ml with molar absorptivity of 1.14 ×103 L mole-1 cm-1. The proposed method is precise, accurate and specific for the quantitative determination of drug in bulk and dosage forms. The results of analysis of commercial formulations and the recovery study of metronidazole suggested that there is no interference from any excipients, which are present in pharmaceutical formulations of metronidazole. Statistical comparison of the results was performed with regard to accuracy and precision using student’s t-test and F-ratio at 95% confidence level. There is no significant difference between the reported and proposed methods with regard to accuracy and precision.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Michael E. El-Kommos ◽  
Samia M. El-Gizawy ◽  
Noha N. Atia ◽  
Noha M. Hosny

A simple and sensitive spectrophotometric method has been developed for the determination of cetirizine (I), ebastine (II), fexofenadine (III), ketotifen (IV), and loratadine (V) based on ion-pair complex formation with erythrosine B. The pink color of the produced complex was measured at 550 nm without solvent extraction. Appropriate conditions were established by studying the color reaction between erythrosine B and the studied drugs to obtain the maximum sensitivity. Beer-Lambert's law is obeyed in the concentration ranges 1–7, 1–8, and 1–6 g/mL for (I, IV), (II, III), and (V), respectively. The method was validated according to ICH guidelines. The suggested method is applicable for the determination of the five investigated drugs in bulk and pharmaceutical dosage forms with excellent recoveries.


2006 ◽  
Vol 89 (2) ◽  
pp. 334-340 ◽  
Author(s):  
Ibrahim A Darwish ◽  
Ibrahim H Refaat ◽  
Hassan F Askal ◽  
Mostafa A Marzouq

Abstract This paper describes the development of a generic spontaneous nonextractive spectrophotometric method for determination of 13 pharmaceutically important 4-quinolone antibiotics. The method was based on the formation of yellow-colored water-soluble ion-pair complexes between 2% (w/v) -naphthol reagent and each of the studied drugs in sulfuric acid medium at room temperature. The formed ion-pair chromogens have maximum absorption peaks in the range of 365391 nm. The concentrations of the reagents and the experimental conditions affecting the reaction were optimized. Under the optimum conditions, linear relationships with good linear coefficients (0.99870.9995) were found between the absorbance and concentration of the investigated drugs in the range of 10350 g/mL. The assay limits of detection and quantitation were 19.9 and 3.432.9 g/mL, respectively. The precision of the method was satisfactory; the values of relative standard deviations did not exceed 2%. The proposed method was successfully applied to the analysis of the investigated drugs in pure and pharmaceutical dosage forms with good accuracy and precision; the percentages of label claim ranged from 97.8102.8 0.351.60%. The results obtained by the proposed spectrophotometric method were comparable with those obtained by the official or reported methods. The proposed method is superior to all the previously reported ion-pair formation-based methods in terms of simplicity because it did not involve extraction procedures for the ion-pair complex. Therefore, this method might be recommended for routine use in quality control laboratories for analysis of the investigated 4-quinolone antibiotics in their pure forms, as well as in pharmaceutical dosage forms.


2012 ◽  
Vol 9 (2) ◽  
pp. 700-704 ◽  
Author(s):  
A. Narendra ◽  
D. Deepika ◽  
M. Mathrusri Annapurna

A new, simple and sensitive spectrophotometric method in ultraviolet region has been developed for the determination of Bosentan in bulk and in pharmaceutical formulations. Bosentan exhibits absorption maxima at 273 nm with apparent molar absorptivity of 1.3293×104L/mol.cm in methanol and octane 1-sulfonic acid solvent mixture. Beer's law was found to be obeyed in the concentration range of 0.1-100 μg/mL. The method was validated as per the ICH guidelines.


Author(s):  
Rúbia Adrieli Sversut ◽  
James Cabral Vieira ◽  
Aline Marques Rosa ◽  
Anil Kumar Singh ◽  
Marcos Serrou Do Amaral ◽  
...  

Author(s):  
RUAA MUAYAD MAHMOOD ◽  
HAMSA MUNAM YASSEN ◽  
SAMAR , NAJWA ISSAC ABDULLA AHMED DARWEESH ◽  
NAJWA ISSAC ABDULLA

Simple, rapid and sensitive extractive spectrophotometric method is presented for the determination of glibenclamide (Glb) based on the formation of ion-pair complex between the Glb and anionic dye, methyl orange (MO) at pH 4. The yellow colored complex formed was quantitatively extracted into dichloromethane and measured at 426 nm. The colored product obeyed Beer’s law in the concentration range of (0.5-40) μg.ml-1. The value of molar absorptivity obtained from Beer’s data was found to be 31122 L.mol-1.cm-1, Sandell’s sensitivity value was calculated to be 0.0159 μg.cm-2, while the limits of detection (LOD) and quantification (LOQ) were found to be 0.1086 and 0.3292 μg.ml-1, respectively. The stoichiometry of the complex created between the Glb and MO was 1:1 as determined via Job’s method of continuous variation and mole ratio method. The method was successfully applied for the analysis of pharmaceutical formulation.


Author(s):  
Sagar Suman Panda ◽  
Ravi Kumar B V V ◽  
D Patanaik

A simple, precise and accurate spectrophotometric method was developed for analysis of the osteoporesis drug alendronate sodium (ALS). The method is based on reaction of the drug with sodium-1,2-naphthoquinone-4-sulphonate (NQS) in presence of alkali to form a brown colored complex giving absorption maximum at 525 nm. The drug obeyed Beer’s law in the range of 5-70 µg/ml with a correlation coefficient of 0.999. The LOD and LOQ values are 1.7 µg/ml and 5.0 µg/ml, respectively. The average recoveries for recovery study were found to be in the range of 99.37%-100.46%. The R.S.D. values for intraday and inter-day precision were found to be 0.48 and 0.62, respectively. The optimized assay conditions were applied successfully for determination of ALS in pharmaceutical dosage forms. No interference was observed from the excipients present in the dosage form. The method is statistically validated as per the ICH requirements.  


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