scholarly journals Titrimetric and Spectrophotometric Assay of Ganciclovir in Pharmaceuticals Using Cerium(IV) Sulphate as the Oxidimetric Agent

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Pavagada J. Ramesh ◽  
Kanakapura Basavaiah ◽  
Cijo M. Xavier ◽  
Kudige N. Prashanth ◽  
Madihalli S. Raghu ◽  
...  
Keyword(s):  
Acid Medium ◽  
Statistical Treatment ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Calibration Graph ◽  
Spectrophotometric Assay ◽  
Ferrous Ammonium ◽  
Sulphuric Acid Medium ◽  
Reaction Schemes

Titrimetric and spectrophotometric assay of ganciclovir (GNC) is described using cerium(IV) sulphate as the oxidimetric reagent. The methods are based on the oxidation of GNC with a measured excess of cerium(IV) sulphate in acid medium followed by determination of the unreacted oxidant by two different reaction schemes. In titrimetry, the unreacted oxidant was determined by back titration with ferrous ammonium sulphate (FAS) in sulphuric acid medium, and spectrophotometry involves the reaction of residual cerium(IV) with p-DMAB to form brownish-coloured p-dimethylamino quinoneimine whose absorbance was measured at 460 nm. In both methods, the amount of cerium(IV) sulphate reacted corresponds to GNC concentration. Titrimetry is applicable over 3–10 mg range where as, in spcetrophotometry, the calibration graph is linear over the range of 2–10 μg mL−1 and the calculated molar absorptivity value is  L mol−1 cm−1. The validity of the proposed methods was tested by analyzing pure and dosage forms containing GNC. Statistical treatment of the results reflects that the proposed procedures are precise, accurate, and easily applicable for the determination of GNC pure form and in pharmaceutical formulations.

scholarly journals Indirect spectrophotometric determination of gentamicin and vancomycin antibiotics based on their oxidation by potassium permanganate

2006 ◽  
Vol 4 (4) ◽  
pp. 708-722 ◽  
Author(s):  
Akram El-Didamony ◽  
Alaa Amin ◽  
Ahmed Ghoneim ◽  
Ayman Telebany
Keyword(s):  
Acid Medium ◽  
Potassium Permanganate ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Reaction Conditions ◽  
Subsequent Determination ◽  
Optimum Reaction ◽  
Acid Orange Ii ◽  
Sulphuric Acid Medium

AbstractFour simple, accurate, sensitive and economical procedures (A–D) for the estimation of gentamicin sulphate and vancomycin hydrochloride, both in pure form and in pharmaceutical formulations have been developed. The methods are based on the oxidation of the studied drugs by a known excess of potassium permanganate in sulphuric acid medium and subsequent determination of unreacted oxidant by reacting it with amaranth dye (method A), acid orange II (method B), indigocarmine (method C) and methylene blue (method D), in the same acid medium at a suitable λmax=521, 485, 610 and 664 nm, respectively. The reacted oxidant corresponds to the drug content. Regression analysis of Beer-Lambert plots showed good correlations in the concentration ranges 4–8, 3–8, 4–9 and 5–9 µg ml−1 with gentamicin and 4–8, 1.5–4, 1.5–4 and 3.5–5.5 µg ml−1 with vancomycin for methods A, B, C, and D, respectively. The molar absorptivity, sandell sensitivity, detection and quantification limits were calculated. The stoichiometric ratios for the cited drugs were studied. The optimum reaction conditions and other analytical parameters were evaluated. The influence of the substance commonly employed as excipients with these drugs were studied. The proposed methods were applied to the determination of these drugs in pharmaceutical formulations. The results have demonstrated that the methods are equally accurate and reproducible as the official methods.

scholarly journals Sensitive Spectrophotometric Methods for the Determination of Ascorbic Acid

2008 ◽  
Vol 5 (1) ◽  
pp. 10-15 ◽  
Author(s):  
H. D. Revanasiddappa ◽  
M. A. Veena
Keyword(s):  
Ascorbic Acid ◽  
Acid Medium ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Maximum Absorbance ◽  
Hydrochloric Acid Medium ◽  
Subsequent Determination ◽  
Sulphuric Acid Medium

Two simple and sensitive spectrophotometric methods (A and B) have been described for the determination of ascorbic acid. Method A is based on the oxidation of ascorbic acid (AA) by known excess of Se(IV) in hydrochloric acid medium and subsequent determination of unreacted Se(IV) by reacting it with iodide in the same acid medium to liberate iodine, which react with starch to form a stable blue coloured iodine-starch complex, which shows maximum absorbance at 590 nm. Method B is based on the oxidation of ascorbic acid (AA) by known excess of Cr(VI) in sulphuric acid medium and the determination of unreacted Cr(VI) with diphenyl carbazide (DPC) under the same acidic medium to produce a stable red-violet coloured species, which shows a maximum absorbance at 550 nm. The reacted oxidants (in methods A and B) correspond to the AA content. The apparent molar absorptivity values are found to be 1.627×104and 1.641×104L mol-1cm-1for methods A and B, respectively. The proposed methods are simple, sensitive and suitable for the routine analysis of AA in pharmaceutical formulations and in real samples.

scholarly journals Extractive Spectrophotometric Determination of Nortriptyline Hydrochloride Using Sudan II, IV and Black B

2001 ◽  
Vol 69 (2) ◽  
pp. 151-160
Author(s):  
A. Amin ◽  
H. Saleh
Keyword(s):  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Ion Pair ◽  
Calibration Graph ◽  
Official Method ◽  
Spectrophotometric Methods ◽  
Sudan Black B ◽  
Relative Standard ◽  
Nortriptyline Hydrochloride

A simple spectrophotometric methods has been developed for the determination of nortriptyline hydrochloride in pure and in pharmaceutical formulations based on the formation of ion-pair complexes with sudun II (SII), sudan (IV) (SIV) and sudan black B (SBB). The selectivity of the method was improved through extraction with chloroform. The optimum conditions for complete extracted colour development were assessed. The absorbance measurements were made at 534, 596 and 649 nm for SII, SIV and SBB complexes, respectively. The calibration graph was linear in the ranges 0.5- 280. 0.5- 37.5 and 0.5 – 31.0 μg ml−1 of the drug usiny the same reagents, respectively. The precision of the procedure was checked by calculating the relative standard deviation of ten replicate determinations on 15 μg ml−1 of nortriptyline HCI and was found to be 1.7, 1.3 and 1.55% using SII, SIV, and SBB complexes, respectively. The molar absorptivity and Sandell sensitivity for each ion-pair were calculated. The proposed methods were successfully applied to the deterniination of pure nortriptyline HCI and in pharmaceutical formulations, and the results demonstrated that the method is equally accurate, precise and reproducible as the official method.

scholarly journals Titrimetric and Spectrophotometric Assay of Pantoprazole in Pharmaceuticals Using Permanganate

2019 ◽  
Vol 53 (1) ◽  
Author(s):  
Kanakapura Basavaiah ◽  
Nagaraju Rajendraprasad ◽  
Kalsang Tharpa ◽  
Urdigere Rangachar Anilkumar ◽  
Salamara Ganeshbhat Hiriyanna ◽  
...  
Keyword(s):  
Standard Addition ◽  
Molar Absorptivity ◽  
Calibration Graph ◽  
Spectrophotometric Assay ◽  
Experimental Conditions ◽  
Accuracy And Precision ◽  
Ich Guidelines ◽  
Sensitivity And Selectivity ◽  
Reaction Stoichiometry

Titrimetric and spectrophotometric assay of pantoprazole sodium (PPS) using permanganate as the oxidimetric reagent is described. In titrimetry, PPS is treated with a measured excess of permanganate in H2SO4 medium followed by the determination of unreacted oxidant by back titrating with a standard iron(II) solution. Spectrophotometry involves addition of a known excess of permanganate to PPS in H2SO4 medium followed by the measurement of absorbance of the residual permanganate at 545 nm. In both the methods, the amount of permanganate reacted corresponds to the PPS content. Experimental conditions that provide wide linear range, maximum sensitivity and selectivity, and accuracy and precisions have been optimized. In titrimetry, the calculations are based on a 1:1 (PPS : KMnO4) reaction stoichiometry and the method is applicable over 1.0-7.0 mg range. In spectrophotometry, Beer’s law is obeyed over the concentration range 15.0-150.0 µg mL-1. The linear regression equation of the calibration graph is A = 0.78 + 0.005 C with a regression coefficient (r) of 0.9982 (n = 11). The apparent molar absorptivity is calculated to be 2.213 × 103 l mol-1cm-1 and the Sandell sensitivity is 0.1954 µg cm-2. The limits of detection (LOD) and quantification (LOQ) calculated as per the ICH guidelines are 0.73 and 2.21 µg mL-1, respectively. Accuracy and precision of the assays were determined by computing the intra-day and inter-day variations at three different levels of PPS; the intra-day and inter-day RSD was < 3.09 % and the accuracy was better than 3.5 %. The methods were successfully applied to the determination of PPS in three different brands of tablets with good accuracy and precision, and without detectable interference by excipients. The accuracy was further ascertained by placebo blank and synthetic mixture analyses and also by recovery experiments via standard-addition procedure.

scholarly journals New Diazo Coupling Reactions for Visible Spectrophotometric Determination of Alfuzosin in Pharmaceutical Preparations

2007 ◽  
Vol 4 (4) ◽  
pp. 496-501 ◽  
Author(s):  
M. Vamsi Krishna ◽  
D. Gowri Sankar
Keyword(s):  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Basic Medium ◽  
Coupling Reactions ◽  
Acetyl Acetone ◽  
Diazo Coupling ◽  
Optimum Reaction ◽  
Diazonium Ion

Simple, rapid and sensitive spectrophotometric procedures were developed for the analysis of Alfuzosin hydrochloride (AFZ) in pure form as well as in pharmaceutical formulations. The methods are based on the reaction of AFZ with nitrite in acid medium to form diazonium ion, which is coupled with ethoxyethylenemaleic ester (Method A) or ethylcyanoacetate (Method B) or acetyl acetone (method C) in basic medium to form azo dyes, showing absorption maxima at 440, 465 and 490 nm respectively. Beer’s law is obeyed in the concentration of 4-20 μg/mL of AFZ for methods A, B and 3-15 μg/mL of AFZ for method C. The molar absorptivity and sandell’s sensitivity of AFZ- ethoxyethylenemaleic ester, AFZ- ethylcyanoacetate and AFZ-acetyl acetone are1.90 × 104, 0.022; 1.93 × 104, 0.021 and 2.67 × 104L mole-1cm-1, 0.015 μg cm-2respectively. The optimum reaction conditions and other analytical parameters were evaluated. The methods were successfully applied to the determination of AFZ in pharmaceutical formulations.

Novel Microwell-Based Spectrophotometric Assay for the Determination of Rosuvastatin Calcium in its Pharmaceutical Formulations

2013 ◽  
Vol 9 (1) ◽  
pp. 54-60
Author(s):  
Tanveer A. Wani ◽  
Ibrahim A. Darwish ◽  
Nasr Y. Khalil
Keyword(s):  
Pharmaceutical Formulations ◽  
Spectrophotometric Assay ◽  
Rosuvastatin Calcium

scholarly journals Spectrophotometric determination of nicradipine and isradipine in pharmaceutical formulations

2009 ◽  
Vol 15 (2) ◽  
pp. 69-76 ◽  
Author(s):  
S.M. Al-Ghannam ◽  
A.M. Al-Olyan
Keyword(s):  
Standard Deviation ◽  
Detection Limit ◽  
Reaction Pathway ◽  
Pharmaceutical Preparations ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Zinc Powder ◽  
Conditional Stability ◽  
Conditional Stability Constant

A sensitive spectrophotometric method was developed for the determination of some 1,4-dihydropyridine compounds namely, nicardipine and isradipine either in pure form or in pharmaceutical preparations. The method is based on the reduction of nicardipine and isradipine with zinc powder and calcium chloride followed by further reduction with sodium pentacyanoaminoferrate (II) to give violet and red products having the absorbance maximum at 546 and 539 nm with nicardipine and isradipine, respectively. Beer's law was obeyed over the concentration range 8.0-180 ?g/ml with the detection limit of 1.67 ?g/ml for nicardipine and 8.0-110 ?g/ml with the detection limit of 1.748 ?g/ml for isradipine. The analytical parameters and their effects on the reported methods were investigated. The molar absorptivity, quantization limit, standard deviation of intercept (Sa), standard deviation of slope (Sb) and standard deviation of the residuals (Sy/x) were calculated. The composition of the result compounds were found 1:1 for nicardipine and 1:2 for isradipine by Job's method and the conditional stability constant (Kf) and the free energy changes (?G) were calculated for compounds formed. The proposed method was applied successfully for the determination of nicardipine and isradipine in their dosage forms. The results obtained were in good agreement with those obtained using the reference or official methods. A proposal of the reaction pathway was presented.

scholarly journals SPECTROPHOTOMETRIC METHODS FOR DETERMINATION OF SOFOSBUVIR AND DACLATASVIR IN PURE AND DOSAGE FORMS

2021 ◽  
pp. 112-119
Author(s):  
MONIR Z. SAAD ◽  
ATEF AMER ◽  
KHALED ELGENDY ◽  
BASEM ELGENDY
Keyword(s):  
Indigo Carmine ◽  
Reference Method ◽  
Standard Addition ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Experimental Conditions ◽  
Fixed Amount ◽  
Alizarin Red ◽  
Spectrophotometric Methods

Objective: Two simple, sensitive and accurate spectrophotometric methods have been developed for the determination of sofosbuvir (SOF) and daclatasvir (DAC) in pure forms and pharmaceutical formulations. Methods: The proposed methods are based on the oxidation of SOF and DAC by a known excess of cerium(IV) ammonium nitrate in sulphuric acid medium followed by determination of unreacted cerium(IV) by adding a fixed amount of indigo carmine (IC) and alizarin red S (ARS) dyes followed by measuring the absorbance at 610 and 360 nm, respectively. The experimental conditions affecting the reaction were studied and optimized. Results: The beer’s law was obeyed in the concentration ranges of 0.2-3.0, 0.2-4.0 for SOF and 0.5-4.5 and 0.5-5.0 μg/ml for DAC using IC and ARS methods, respectively with a correlation coefficient ≥ 0.9991. The calculated molar absorptivity values are 2.354 × 104, 1.933 × 104 for SOF and 1.786 × 104 and 2.015 × 104 L/mol. cm for DAC using IC and ARS methods, respectively u. The limits of detection and quantification are also reported. Intra-day and inter-day precision and accuracy of the methods have been evaluated. Conclusion: The methods were successfully applied to the assay of SOF and DAC in tablets and the results were statistically compared with those of the reference method by applying Student’s t-test and F-test. No interference was observed from the common tablet excipients. The accuracy and reliability of the methods were further ascertained by performing recovery studies using the standard addition method.

scholarly journals Nitroso-R-salt as a sensitive spectrophotometric reagent for the determination of paracetamol in pharmaceutical preparations

2009 ◽  
Vol 6 (3) ◽  
pp. 570-577
Author(s):  
Baghdad Science Journal
Keyword(s):  
Aqueous Solution ◽  
Statistical Difference ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Calibration Graph ◽  
Subsequent Reaction ◽  
Experimental Conditions ◽  
Colored Complex ◽  
British Pharmacopoeia

Nitroso-R-salt is proposed as a sensitive spectrophotometric reagent for the determination of paracetamol in aqueous solution. The method is based on the reaction of paracetamol with iron(III) and subsequent reaction with nitroso-R-salt to yield a green colored complex with maximum absorption at 720 nm. Optimization of the experimental conditions was described. The calibration graph was linear in the concentration range of 0.1 – 2.0 ?g mL-1 paracetamol with a molar absorptivity of 6.9 × 104 L mol-1 cm-1. The method was successfully applied to the determination of paracetamol in pharmaceutical preparations without any interference from common excipients. The method has been statistically evaluated with British Pharmacopoeia method and no statistical difference between methods was found at the 95% confidence level.

scholarly journals Spectrophotometric method for the determination of Captopril in pharmaceutical formulations

2013 ◽  
Vol 10 (3) ◽  
pp. 965-970
Author(s):  
Baghdad Science Journal
Keyword(s):  
Aqueous Solution ◽  
Spectrophotometric Method ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Maximum Absorption ◽  
Neutral Medium ◽  
Pharmaceutical Tablets ◽  
Colored Product ◽  
Sensitive Spectrophotometric Method

A simple, rapid and sensitive spectrophotometric method has been developed for the determination of captopril in aqueous solution. The method is based on reaction of captopril with 2,3-dichloro 1,4- naphthoquinon(Dichlone) in neutral medium to form a stable yellow colored product which shows maximum absorption at 347 nm with molar absorptivity of 5.6 ×103 L.mole-1. cm-1. The proposed method is applied successfully for determination of captopril in commercial pharmaceutical tablets.

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