scholarly journals Sensitive Spectrophotometric Methods for the Determination of Gatifloxacin in Pharmaceuticals Using Bromate-Bromide, Methylene Blue and Rhodamine-B as Reagents

2007 ◽  
Vol 4 (2) ◽  
pp. 154-161 ◽  
Author(s):  
K. Basavaiah ◽  
U. R. Anil Kumar
Keyword(s):  
Methylene Blue ◽  
Hydrochloric Acid ◽  
Acid Medium ◽  
Rhodamine B ◽  
Pharmaceutical Formulations ◽  
Fixed Amount ◽  
Spectrophotometric Methods ◽  
Hydrochloric Acid Medium

Two new simple, precise, rapid and extraction-free spectrophotometric methods are proposed for the determination of gatifloxacin(GTF) using bromate-bromide mixture and two dyes, methylene blue and rhodamine B, as reagents. Spectrophotometric methods entail the addition of a known excess of bromate-bromide mixture to GTF in hydrochloric acid medium followed by determination of residual bromine by reacting with a fixed amount of either methylene blue and measuring the absorbance at 665 nm (Method A) or rhodamine B and measuring the absorbance at 555 nm (Method B). Beer᾽s law is obeyed in the ranges, 0.5-5.0 and 0.2-1.5 μg mL-1for method A and method B, respectively. The apparent molar absorptivities are calculated to be 5.6×104and 9.6×104L mol-1cm-1for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.0071 and 0.0042 μg cm-2. The methods were successfully applied to the assay of GTF in pharmaceutical formulations with satisfactory results.

scholarly journals Simple Spectrophotometric Methods for the Determination of Zidovudine in Pharmaceuticals Using Chloramine-T, Methylene Blue and Rhodamine-B as Reagents

2006 ◽  
Vol 3 (3) ◽  
pp. 173-181
Author(s):  
K. Basavaiah ◽  
U. R. Anil Kumar
Keyword(s):  
Methylene Blue ◽  
Rhodamine B ◽  
Pharmaceutical Formulations ◽  
Fixed Amount ◽  
Spectrophotometric Methods ◽  
Hydrochloric Acid Medium ◽  
Ich Guidelines ◽  
Chloramine T ◽  
Bulk Drug

Two new spectrophotometric methods are proposed for the determination of zidovudine(ZDV) in pharmaceuticals. The methods use chloramine-T (CAT) and two dyes, methylene blue and rhodamine-B, as reagents and are based on adding of a known excess of CAT to ZDV in hydrochloric acid medium followed by determination of residual oxidant by reacting with a fixed amount of either methylene blue and measuring the absorbance at 665 nm (Method A) or rhodamine B and measuring the absorbance at 555 nm (Method B). In both methods, the amount of CAT reacted corresponds to the amount of ZDV. The absorbance measured is found to increase linearly with concentration of ZDV. Under the optimum conditions, ZDV could be assayed in the concentration range 1.25-15.0 and 0.25-3.0 μg ML-1by method A and method B, respectively. The apparent molar absorptivities are calculated to be 7.7x103and 5.6x104L mol-1cm-1for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.035 and 0.005 μg cm-2. The limits of detection and quantification are reported for both methods. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The proposed methods can be readily utilized for bulk drug and in pharmaceutical formulations.

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 Rapid titrimetric and spectrophotometric methods for salbutamol sulphate in pharmaceuticals using N-bromosuccinimide

2007 ◽  
Vol 57 (1) ◽  
pp. 87-98 ◽  
Author(s):  
Kanakapura Basavaiah ◽  
Bankavadi Somashekar ◽  
Veeraiah Ramakrishna
Keyword(s):  
Methylene Blue ◽  
Acid Medium ◽  
Rhodamine B ◽  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Acetic Acid Medium ◽  
Fixed Amount ◽  
Salbutamol Sulphate ◽  
Spectrophotometric Methods

Rapid titrimetric and spectrophotometric methods for salbutamol sulphate in pharmaceuticals using N-bromosuccinimide One titrimetric and two spectrophotometric methods which are simple, sensitive and rapid are described for the assay of salbutamol sulphate (SBS) in bulk drug and in tablet dosage forms using N-bromosuccinimide (NBS) and two dyes, rhodamine-B and methylene blue, as reagents. In titrimetry, aqueous solution of salbutamol sulphate is treated with a measured excess of NBS in acetic acid medium and after the oxidation of SBS is complete, the unreacted oxidant is determined iodometrically. Spectrophotometric methods entail addition of a known excess of NBS in acid medium followed by the determination of residual oxidant by reacting with a fixed amount of either rhodamine B and measuring the absorbance at 555 nm (method A) or methylene blue and measuring the absorbance at 665 nm (method B). In all methods, the amount of NBS reacting corresponds to the amount of SBS content. Titrimetric method is applicable over 1.74 x 10-4 - 8.68 x 10-4 mol L-1 range and the reaction stoichiometry is found to be 1:6 (SBS:NBS). In spectrophotometric methods, the absorbance is found to increase linearly with the concentration of SBS, which is corroborated by the correlation of coefficients of 0.9993 and 0.9988 for method A and method B, respectively. The systems obey Beer's law for 0.25-1.75 μg mL-1 (method A) and 0.5-5.0 μg mL-1 (method B). The calculated apparent molar absorptivity values were found to be 2.10 x 105 and 6.16 x 104 L mol-1 cm-1, for method A and method B, respectively. The limits of detection and quantification are also reported for both spectrophotometric methods. Intraday and inter-day precision and accuracy for the developed methods were evaluated. The methods were successfully applied to the assay of SBS in tablet and capsule formulations and the results were statistically compared with those of a reference method. No interference was observed from common tablet adjuvants. The accuracy and reliability of the methods were further ascertained by recovery experiments via the standard-addition technique.

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 Kinetic determination of ultratrace amounts of iodide in perchloric-hydrochloric acid medium

1972 ◽  
Vol 21 (9) ◽  
pp. 1169-1173 ◽  
Author(s):  
Tsutomu FUKASAWA ◽  
Masaaki IWATSUKI ◽  
Keiko UESUGI
Keyword(s):  
Hydrochloric Acid ◽  
Acid Medium ◽  
Kinetic Determination ◽  
Hydrochloric Acid Medium

scholarly journals Sensitive Spectrophotometric Determination of Atenolol in Pharmaceutical Formulations Using Bromate-Bromide Mixture as an Eco-Friendly Brominating Agent

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Kudige N. Prashanth ◽  
Kanakapura Basavaiah
Keyword(s):  
Correlation Coefficients ◽  
Reference Method ◽  
Pharmaceutical Formulations ◽  
Fixed Amount ◽  
Spectrophotometric Methods ◽  
Bulk Drug ◽  
Orange Color ◽  
Yellowish Orange

Three simple and sensitive spectrophotometric methods are proposed for the determination of atenolol (ATN) in bulk drug and tablets. The methods are based on the bromination of ATN by the bromine generatedin situby the action of the acid on the bromate–bromide mixture followed by the determination of unreacted bromine by reacting with a fixed amount of either meta-cresol purple (MCP) and measuring the absorbance at 540 nm (method A) and 445 nm (method B) or erioglaucine (EGC) and measuring the absorbance at 630 nm (method C). Beer's law is valid within the concentration ranges of 1.0–20.0, 2.0–40.0 and 1.0–8.0 μg/mL for method A, method B and method C, respectively. The calculated molar absorptivities were found to be 1.20×104, 4.51×103and3.46×104  L/mol⋅cmfor method A, method B and method C, respectively. Sandell’s sensitivity values, correlation coefficients, limits of detection and quantification are also reported. Recovery results were statistically compared with those of a reference method by applying Student’st- andF-test. The novelty of the present study is the measurement of two different colors using MCP, that is, red-pink color of MCP in acid medium at 540 nm and yellowish-orange color of brominated MCP at 445 nm.

scholarly journals Sensitive and selective methods for the determination of cyproheptadine in tablets using N-bromosuccinimide and two dyes

2012 ◽  
Vol 18 (3) ◽  
pp. 449-458 ◽  
Author(s):  
Srinivas Raghu ◽  
Kanakapura Basavaiah
Keyword(s):  
Acid Medium ◽  
Reference Method ◽  
Fixed Amount ◽  
Limits Of Detection ◽  
Spectrophotometric Methods ◽  
Cyproheptadine Hydrochloride ◽  
Bulk Drug ◽  
Reaction Stoichiometry

One titrimetric and two spectrophotometric methods are described for the determination of cyproheptadine hydrochloride (CPH) in bulk drug and tablets employing N-bromosuccinimide (NBS) as a brominating agent and two dyes, erioglaucine (EG) and meta-cresol purple (MCP) as auxiliary reagents. In titrimetry, a measured excess of NBS is added to an acidified solution of CPH and the unreacted NBS is determined iodometrically. Spectrophotometry involves the addition of a known excess of NBS to CPH in acid medium followed by estimation of residual NBS by reacting with a fixed amount of either erioglaucin and measuring the absorbance at 540 nm (method A) or meta-cresol purple and measuring the absorbance at 630 nm (method B). Titrimetric procedure is applicable over the range of 1.5-15 mg of CPH, and the reaction stoichiometry is found to be 1: 2 (CPH: NBS). The spectrophotometric methods are applicable over the ranges of 0.1-2.0 ?g mL-1 (method A) and 0.4-12 ?g mL-1 (method B). The molar absorptivities are calculated to be 1.4 ? 105 and 2.2?104 Lmol-1cm-1 for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.0023 and 0.0141 ?g cm-2. The limits of detection are calculated and found to be 0.03 and 0.24 ?g mL-1 for method A and method B, respectively with corresponding limits of quantification 0.09 and 0.71. The methods were applied to the assay of CPH in tablets, and the results were compared statistically with those of a reference method.

scholarly journals New Sensitive Spectrophotometric Methods for the Determination of Raloxifene Hydrochloride in Pharmaceuticals Using Bromate-Bromide,Methyl Orange and Indigo Carmine

2006 ◽  
Vol 3 (4) ◽  
pp. 242-249 ◽  
Author(s):  
K Basavaiah ◽  
U. R. Anil Kumar
Keyword(s):  
Methyl Orange ◽  
Indigo Carmine ◽  
Reference Method ◽  
Standard Addition ◽  
Fixed Amount ◽  
Spectrophotometric Methods ◽  
Hydrochloric Acid Medium ◽  
Student’S T ◽  
Raloxifene Hydrochloride

Two new sensitive spectrophotometric methods are proposed for the determination of raloxifene hydrochloride (RLX) using bromate-bromide mixture and two dyes, methyl orange and indigocarmine, as reagents. The methods entail the addition of a known excess of bromate-bromide mixture to RLX in hydrochloric acid medium followed by determination of residual bromine by reacting with a fixed amount of either methyl orange and measuring the absorbance at 520 nm (Method A) or indigo carmine and measuring the absorbance at 610 nm (Method B). In both methods, the amount of bromine reacted corresponds to the amount of RLX. The absorbance is found to increase linearly with concentration of RLX. Under the optimum conditions, RLX could be assayed in the concentration range 0.1-2.0 and 0.5-6.0 μg mL-1by method A and method B, respectively. The apparent molar absorptivities are calculated to be 1.9×105and 4.5×104L mol-1cm-1for method A and method B, respectively, and the corresponding Sandell sensitivity values are 0.003 and 0.011 μg cm-2. The limits of detection and quantification are also reported for both methods. Intra-day and inter-day precision and accuracy of the developed methods were evaluated as per the current ICH guidelines. The methods were successfully applied to the assay of RLX in its tablet formulation and the results were compared with those of a reference method by calculating the Student’s t-value and F-value. No interference was observed from common tablet adjuvants. The accuracy and reliability of the methods were further ascertained by recovery experiments via standard-addition procedure.

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