scholarly journals Titrimetric and Spectrophotometric Assay of Oxcarbazepine in Pharmaceuticals Using N-Bromosuccinimide and Bromopyrogallol Red

2011 ◽  
Vol 2011 ◽  
pp. 1-8
Author(s):  
Nagaraju Rajendraprasad ◽  
Kanakapura Basavaiah ◽  
Kanakapura B. Vinay
Keyword(s):  
Spectrophotometric Method ◽  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Bromopyrogallol Red ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Comparison Of The Results

Titrimetric and spectrophotometric methods are described for the determination of oxcarbazepine (OXC) in bulk drug and in tablets. The methods use N-bromosuccinimide (NBS) and bromopyrogallol red (BPR) as reagents. In titrimetry (method A), an acidified solution of OXC is titrated directly with NBS using methyl orange as indicator. Spectrophotometry (method B) involves the addition of known excess of NBS to an acidified solution of OXC followed by the determination of the unreacted NBS by reacting with BPR and measuring the absorbance of the unreacted dye at 460 nm. Titrimetry allows the determination of 6–18 mg of OXC and follows a reaction stoichiometry of 1 : 1 (OXC : NBS), whereas spectrophotometry is applicable over the concentration range of 0.8–8.0 μg mL-1. Method B with a calculated molar absorptivity of2.52×104 L mol-1 cm-1is the most sensitive spectrophotometric method ever developed for OXC. The optical characteristics such as limits of detection (LOD), quantification (LOQ), and Sandell's sensitivity values are also reported for the spectrophotometric method. The accuracy and precision of the methods were studied on intraday and interday basis. The methods described could usefully be applied to routine quality control of tablets containing OXC. No interference was observed from common pharmaceutical adjuvants. Statistical comparison of the results with a reference method shows an excellent agreement and indicates no significant difference in accuracy and precision. The reliability of the methods was further ascertained by recovery studies in standard addition procedure.

scholarly journals Indirect spectrophotometric determination of diltiazem hydrochloride in pure form and pharmaceutical formulations

2005 ◽  
Vol 3 (3) ◽  
pp. 520-536 ◽  
Author(s):  
Akram El-Didamony
Keyword(s):  
Reference Method ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Pure Form ◽  
Diltiazem Hydrochloride ◽  
Spectrophotometric Methods ◽  
Chromotrope 2R ◽  
Significant Difference ◽  
Comparison Of The Results

AbstractThree simple, accurate, and sensitive spectrophotometric methods (A, B and C) have been described for the indirect assay of diltiazem hydrochloride (DIL.HCl), either in pure form or in pharmaceutical formulations. The first method (A) is based on the oxidation of DIL.HCl by N-bromosuccinimide (NBS) and determination of unconsumed NBS by measuring the decrease in absorbance of amaranth dye (AM) at a suitable λmax=521 nm. Other methods (B) and (C) involve the addition of excess cerric ammonium sulfate (CAS) and subsequent determination of the unconsumed oxidant by a decrease in the red color of chromotrope 2R (C2R) at a suitable λmax=528 nm or a decrease in the orange-pink color of rhodamine 6G (Rh6G) at λmax=525 nm, respectively. Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges 3.0–9.0, 3.5–7.0 and 3.5–6.3 μg ml−1 for methods A, B and C, respectively. The apparent molar absorptivity, Sandell's sensitivity, detection and quantification limits were calculated. The proposed methods have been applied successfully for the analysis of the drug in its pure form and its dosage form. No interference was observed from a common pharmaceutical adjuvant. Statistical comparison of the results with the reference method shows excellent agreement and indicates no significant difference in accuracy and precision.

scholarly journals Cerimetric determination of simvastatin in pharmaceuticals based on redox and complex formation reactions

2018 ◽  
Vol 33 (2) ◽  
pp. 21
Author(s):  
Kanakapura Basavaiah ◽  
Okram Zenita Devi
Keyword(s):  
Limit Of Detection ◽  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Experimental Conditions ◽  
Spectrophotometric Methods ◽  
Fixed Quantity ◽  
Bulk Drug ◽  
Student’S T

Two sensitive spectrophotometric methods are described for the determination of simvastatin (SMT) in bulk drug and in tablets. The methods are based on the oxidation of SMT by a measured excess of cerium (IV) in acid medium followed by determination of unreacted oxidant by two different reaction schemes. In one procedure (method A), the residual cerium (IV) is reacted with a fixed concentration of ferroin and the increase in absorbance is measured at 510 nm. The second approach (method B) involves thereduction of the unreacted cerium (IV) with a fixed quantity of iron (II), and the resulting iron (III) is complexed with thiocyanate and the absorbance measured at 470 nm. In both methods, the amount of cerium (IV) reacted corresponds to SMT concentration. The experimental conditions for both methods were optimized. In method A, the absorbance is found to increase linearly with SMT concentration (r = 0.9995) whereas in method B, the same decreased (r = -0.9943). The systems obey Beer’s law for 0.6-7.5 and 0.5-5.0 μg mL-1 for method A and method B, respectively. The calculated molar absorptivity values are 2.7 X 104 and 1.06 X 105 Lmol-1 cm-1, respectively; and the corresponding sandel sensitivity values are 0.0153 and 0.0039μg cm-2, respectively. The limit of detection (LOD) and quantification (LOQ) are reported for both methods. Intra-day and inter-day precision, and accuracy of the methods were established as per the current ICH guidelines. The methods were successfully applied to the determination of SMT in tablets and the results were statistically compared with those of the reference method by applying the Student’s t-test and F-test. No interference was observed from the common excipients added to tablets. The accuracy and validity of the methods were further ascertained by performing recovery experiments via standard addition procedure.

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 Of bromination reaction for the spectrophotometric assay of domperidone in pharmaceuticals

2011 ◽  
Vol 17 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Zenita Devi ◽  
K. Basavaiah ◽  
K.B. Vinay
Keyword(s):  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Reference Method ◽  
Standard Addition ◽  
Limit Of Quantification ◽  
Fixed Amount ◽  
Spectrophotometric Methods ◽  
Significant Difference ◽  
Bulk Drug

Three simple and sensitive spectrophotometric methods are described for the determination of domperidone (DOM) in bulk drug and in dosage forms using bromate-bromide mixture as brominating agent in acid medium and three dyes, meta-cresol purple (MCP), amaranth (AMR) and erioglaucine (EGC). The methods involve the addition of a known excess of bromate-bromide mixture to an acidified solution of DOM followed by the determination of the residual bromine by reacting with a fixed amount of either MCP dye and measuring the absorbance at 530 nm (method A) or AMR dye and measuring the absorbance at 520 nm (method B) or EGC dye and measuring the absorbance at 630 nm (method C). Beer?s law is obeyed over the concentration ranges, 0.63 - 10.0, 0.25-4.0 and 0.13-2.0 ?g mL-1 for method A, method B and method C, respectively. The apparent molar absorptivities are calculated to be 3.751 ? 104, 6.604 ? 104 and 1.987 ? 105 L mol-1cm-1 for method A, method B and method C, respectively and the corresponding sandell sensitivity values are 0.011, 0.006 and 0.002 ?g cm-2. The limit of detection and the limit of quantification are also reported for all the three methods. No interference was observed from common additives found in pharmaceutical preparations. Statistical comparisons of the results with those of the reference method showed an excellent agreement, and indicated no significant difference in accuracy and precision. The accuracy and reliability of the methods were further ascertained by performing recovery tests via standard-addition technique.

scholarly journals Simple and extraction-free spectrophotometric methods for risperidone in pure form and in dosage forms

2013 ◽  
Vol 19 (1) ◽  
pp. 121-128 ◽  
Author(s):  
Hemavathi Deepakumari ◽  
Shiramahally Mallegowda ◽  
Kanakapura Vinay ◽  
Hosakere Revanasiddappa
Keyword(s):  
Limit Of Detection ◽  
Ion Pairs ◽  
Pharmaceutical Preparations ◽  
Reference Method ◽  
Standard Addition ◽  
Bromophenol Blue ◽  
Phenol Red ◽  
Spectrophotometric Methods ◽  
Accuracy And Precision

Two simple, sensitive and extraction-free spectrophotometric methods are described for the estimation of risperidone (RSP) in both pure and in pharmaceutical preparations. The proposed methods are based on the formation of ion-pair complex between RSP and the dyes, bromophenol blue (BPB) in method A and Phenol red (PR) in method B at room temperature to form yellow colored products which show maximum absorbance at 410 and at 400 nm in methods A and B, respectively. Beer's law was obeyed in the concentration range of 0.5-10 and 0.5-25 ?g mL-1 in methods A and B with apparent molar absorptivities of 3.43 ? 104 and 0.85 ? 104 L moL-1 cm-1, respectively. The limit of detection for method A is found to be 0.0056 and for method B is 0.132 ?g mL-1. The composition of the ion-pairs was established by Job?s method and it was found to be 1:1 for both the methods A and B. The proposed methods have been applied successfully to the determination of RSP in pharmaceutical preparations. The results were statistically compared with those of a reference method by applying the Student?s t-test and F-test. The methods developed were validated for accuracy and precision by performing recovery experiments via standard addition technique.

scholarly journals A kinetic spectrophotometric method for the determination of lansoprazole in pharmaceutical formulations

2006 ◽  
Vol 71 (10) ◽  
pp. 1107-1120 ◽  
Author(s):  
Nafisur Rahman ◽  
Zehra Bano ◽  
Hejaz Azmi ◽  
Mohammad Kashif
Keyword(s):  
Spectrophotometric Method ◽  
Room Temperature ◽  
Pharmaceutical Formulations ◽  
Accuracy And Precision ◽  
Significant Difference ◽  
Kinetic Spectrophotometric ◽  
Comparison Of The Results ◽  
Calibration Equations ◽  
Method Show

Asimple kinetic spectrophotometric method has been developed for the determination of lansoprazole in pharmaceutical formulations. The method is based on the oxidation of the drug with alkaline potassium permanganate at room temperature. The reaction was followed spectrophotometrically by measuring the increase in the absorbance owing to the formation of MnO 42? at 610 nm (Method A) and the decrease in the absorbance at 530 nm due to the disapperance of MnO4? (Method B). Calibration procedures were adopted for the assay of the drug. The calibration curves were linear over the concentration ranges of 5-150 and 5-70?g ml-1, with the corresponding calibration Equations: rate = -3.915x10-6 + 5.271x10-5 c and ?A = 1.04x 10-3 + 1.78x10-3 c for methods A, and B, respectively. A statistical comparison of the results of the proposed procedures with those of the reference spectrophotometric method show excellent agreement and indicated no significant difference between the compared methods in terms of accuracy and precision. Interval hypothesis tests were also performed, which indicated that the true bias of all samples was less than ? 2 %. .

scholarly journals Application of bromate-bromide mixture as a green brominating agent for the spectrophotometric determination of atenolol in pharmaceuticals

2012 ◽  
Vol 18 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Nagaraj Prashanth ◽  
Kanakapura Basavaiah ◽  
Sameer Abdulrahman ◽  
Nagaraju Rajendraprasad ◽  
Basavaiah Vinay
Keyword(s):  
Reference Method ◽  
Standard Addition ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Spectrophotometric Methods ◽  
Highly Sensitive ◽  
Bromination Reaction ◽  
Excess Iodide ◽  
Good Agreement

Two highly sensitive spectrophotometric methods are proposed for the quantification of atenolol (ATN) in pure drug as well as in pharmaceutical formulations. The methods are based on the bromination reaction of ATN with a known excess of bromate-bromide mixture in acid medium followed by the determination of unreacted bromine. The residual bromine is determined by its reaction with excess iodide and the liberated iodine (I3?) is either measured at 360 nm (method A) or reacted with starch followed by the measurement of the starch-iodine chromogen at 570 nm (method B). Under the optimum conditions, ATN could be assayed in the concentration ranges of 0.5-9.0 and 0.3-6.0?g mL-1 for method A and method B, respectively, with corresponding molar absorptivity values of 2.36?104 and 2.89?104 L/mol.cm. Sandell?s sensitivity values are found to be 0.0113 and 0.0092 ?g/cm2 for method A and method B, respectively. The proposed methods were successfully applied to the analysis of different commercial brands of pharmaceutical formulations and the results obtained by the proposed methods were in good agreement with those obtained using the reference method. The reliability of the methods was further ascertained by recovery studies using standard- addition method.

scholarly journals Development and application of spectrophotometric method for quantitative determination of Metronidazole in pure and tablet formulations

2016 ◽  
Vol 2 (1) ◽  
pp. 28 ◽  
Author(s):  
Zeeshan Masood ◽  
Muhammad Tayyab Ansari ◽  
Sharjeel Adnan ◽  
Muhammad Asad ◽  
Muhammad Farooq ◽  
...  
Keyword(s):  
Quantitative Determination ◽  
Spectrophotometric Method ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Nitrite Ion ◽  
Colored Complex ◽  
Accuracy And Precision ◽  
Significant Difference

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.

scholarly journals Sensitive and Selective Spectrophotometric Determination of Gabapentin in Capsules Using Two Nitrophenols as Chromogenic Agents

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Sameer A. M. Abdulrahman ◽  
Kanakapura Basavaiah
Keyword(s):  
Picric Acid ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Ion Pair ◽  
Lewis Base ◽  
Pure Form ◽  
Experimental Conditions ◽  
Spectrophotometric Methods ◽  
Significant Difference

Two simple and selective spectrophotometric methods have been proposed for the determination of gabapentin (GBP) in pure form and in capsules. Both methods are based on the proton transfer from the Lewis acid such as 2,4,6-trinitrophenol (picric acid; PA) or 2,4-dinitrophenol (2,4-DNP) to the primary amino group of GBP which works as Lewis base and formation of yellow ion-pair complexes. The ion-pair complexes formed show absorption maximum at 415 and 420 nm for PA and 2,4-DNP, respectively. Under the optimized experimental conditions, Beer's law is obeyed over the concentration ranges of 1.25–15.0 and 2.0–18.0 μg mL−1GBP for PA and 2,4-DNP methods, respectively. The molar absorptivity, Sandell's sensitivity, detection and, quantification limits for both methods are also reported. The proposed methods were applied successfully to the determination of GBP in pure form and commercial capsules. Statistical comparison of the results was performed using Student'st-test and F-ratio at 95% confidence level, and there was no significant difference between the reference and proposed methods with regard to accuracy and precision. Further, the validity of the proposed methods was confirmed by recovery studies via standard addition technique.

Simple and Selective Titrimetric and Spectrophotometric Methods for the Determination of Loratadine Using Bromate-Bromide, Methyl Orange and Methylene Blue

2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Venkatachalam K ◽  
Niranjani S ◽  
Raju T
Keyword(s):  
Methylene Blue ◽  
Methyl Orange ◽  
Reference Method ◽  
Standard Addition ◽  
Molar Absorptivity ◽  
Stoichiometric Ratio ◽  
Fixed Amount ◽  
Spectrophotometric Methods ◽  
Student’S T

One indirect titrimetric and two indirect visible spectrophotometric methods were described for the determination of loratadine in bulk drug and in its formulations. The methods used bromate-bromide, methyl orange and methylene blue as reagents. In titrimetry (method A), loratadine was treated with a known excess of bromate-bromide mixture in acidic medium and the residual bromine was back titrated iodometrically after the reaction between loratadine and in situ bromine was ensured to be complete. In spectrophotometric methods, the excess of bromine was estimated by treating with a fixed amount of either methyl orange (method B) and measuring the absorbance at 520 nm or methylene blue (method C) and measuring the absorbance at 680 nm. In all the methods, the amount of reacted bromine corresponded to the loratadine content. Titrimetric method was applicable over 1-8 mg range and the calculations were based on a 1:0.666 (loratadine:bromate) stoichiometric ratio. In spectrophotometry, the calibration graphs were found to be linear over 150- 350 and 1.75-3.5 μg mL-1 for method B and method C, respectively, with corresponding molar absorptivity values of 9.15 × 102 and 1.10 × 105 L mol-1 cm-1. Accuracy and precision of the assays were determined by computing the intra-day and inter-day variations at three different levels of loratadine. The methods were successfully applied to the assay of loratadine in tablet preparations and the results were compared with those of a reference method by applying Student’s t and F-tests. No interference was observed from common pharmaceutical excipients. The reliability of the methods was further ascertained by performing recovery tests by standard addition method

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