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

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.

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Rapid titrimetric and spectrophotometric determination of ofloxacin in pharmaceuticals using N-bromosuccinimide

Brazilian Journal of Pharmaceutical Sciences ◽

10.1590/s1984-82502011000200006 ◽

2011 ◽

Vol 47 (2) ◽

pp. 251-260 ◽

Cited By ~ 2

Author(s):

Kanakapura Basavaiah Vinay ◽

Hosakere Doddarevanna Revanasiddappa ◽

Okram Zenita Devi ◽

Pavagada Jagannathamurthy Ramesh ◽

Kanakapura Basavaiah

Keyword(s):

Indigo Carmine ◽

Reference Method ◽

Standard Addition ◽

Addition Method ◽

Fixed Amount ◽

Spectrophotometric Methods ◽

Analytical Reagent ◽

Bulk Drug ◽

Reaction Stoichiometry

One titrimetric and two spectrophotometric methods have been described for the determination of ofloxacin (OFX) in bulk drug and in tablets, employing N-Bromosuccinimide as an analytical reagent. The proposed methods involve the addition of a known excess of NBS to OFX in acid medium, followed by determination of unreacted NBS. In titrimetry, the unreacted NBS is determined iodometrically, and in spectrophotometry, unreacted NBS is determined by reacting with a fixed amount of either indigo carmine (Method A) or metanil yellow (Method B). In all the methods, the amount of NBS reacted corresponds to the amount of OFX. Titrimetry allows the determination of 1-8 mg of OFX and the calculations are based on a 1:5 (OFX:NBS) reaction stoichiometry. In spectrophotometry, Beer's law is obeyed in the concentration ranges 0.5-5.0 µg/mL for method A and 0.3-3.0 µg/mL for method B. The molar absorptivities are calculated to be 5.53x10(4) and 9.24x10(4) L/mol/cm for method A and method B, respectively. The methods developed were applied to the assay of OFX in tablets, and results compared statistically with those of a reference method. The accuracy and reliability of the methods were further ascertained by performing recovery tests via the standard-addition method.

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Titrimetric and Spectrophotometric Determination of Metaprolol tartrate in Pharmaceuticals Using N-Bromosuccinimide

E-Journal of Chemistry ◽

10.1155/2007/739141 ◽

2007 ◽

Vol 4 (1) ◽

pp. 117-127 ◽

Cited By ~ 1

Author(s):

K. Basavaiah ◽

B. C. Somashekar

Keyword(s):

Methyl Orange ◽

Indigo Carmine ◽

Reference Method ◽

Standard Addition ◽

Reaction Conditions ◽

Fixed Amount ◽

Spectrophotometric Methods ◽

Bulk Drug ◽

Reaction Stoichiometry

One titrimetric and two spectrophotometric methods are presented for the assay of metaprolol tartrate (MPT) in bulk drug and in tablets. The methods employ N-bromosuccinimide (NBS) as the oxidimetric reagent and two dyes, methyl orange and indigo carmine as spectrophotometric reagents. In titrimetry, an acidified solution of MPT is treated with a known excess amount of NBS and after a definite time, the unreacted oxidant is determined by iodometric back titration. Spectrophotometry involves adding a measured excess of NBS to MPT in acid medium followed by determination of residual NBS 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 all the methods, the amount of NBS reacted corresponds to the amount of MPT. Reaction conditions have been optimized. Titrimetry allows the determination of 1 - 12 mg of MPT and the calculations are based on a 1: 4 (MPT: NBS) reaction stoichiometry. In spectrophotometry, the measured absorbance is found to increase linearly with the concentration of MPT serving as basis for quantitation. The systems obey Beer’s law for 0.5 - 4.0 μg mL-1and 1.25 - 10.0 μg mL-1for method A and method B, respectively. The apparent absorptivities are calculated to 1.07 × 105be and 4.22 × 104L mol cm-1for method A and method B, respectively. The methods developed were applied to the assay of MPT in commercial tablet formulations, and the results were compared statistically with those of a reference method. The accuracy and reliability of the methods were further ascertained by performing recovery tests via standard-addition method.

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

Journal of Analytical Methods in Chemistry ◽

10.1155/2012/810156 ◽

2012 ◽

Vol 2012 ◽

pp. 1-12 ◽

Cited By ~ 4

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.

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Of bromination reaction for the spectrophotometric assay of domperidone in pharmaceuticals

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq100616057d ◽

2011 ◽

Vol 17 (1) ◽

pp. 81-89 ◽

Cited By ~ 1

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.

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

Eclética Química Journal ◽

10.26850/1678-4618eqj.v33.2.2008.p21-28 ◽

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.

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

International Journal of Applied Pharmaceutics ◽

10.22159/ijap.2021v13i6.42564 ◽

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.

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Sensitive and rapid titrimetric and spectrophotometric methods for the determination of stavudine in pharmaceuticals using bromate-bromide and three dyes

Anais da Academia Brasileira de Ciências ◽

10.1590/s0001-37652008000200003 ◽

2008 ◽

Vol 80 (2) ◽

pp. 253-262 ◽

Cited By ~ 3

Author(s):

Kanakapura Basavaiah ◽

Veeraiah Ramakrishna ◽

Chikkaswamy Somashekar ◽

Urdigere R. Anil Kumar

Keyword(s):

Dosage Forms ◽

Linear Increase ◽

Thymol Blue ◽

Fixed Amount ◽

Rapid Methods ◽

Spectrophotometric Methods ◽

Back Titration ◽

Bulk Drug ◽

Hcl Medium

Four sensitive and rapid methods for the determination of stavudine (STV) in bulk drug and in dosage forms were developed and optimized. In titrimetry, aqueous solution of STV was treated with a known excess of bromate-bromide in HCl medium followed by estimation of unreacted bromine by iodometric back titration. Spectrophotometric methods involve the addition of a measured excess of bromate-bromide in HCl medium and subsequent estimation of the residual bromine by reacting with a fixed amount of methyl orange, indigocarmine or thymol blue followed by measurement of absorbance at 520 nm (method A), 610 nm (method B) or 550 nm (method C). In all the methods, the amount of bromate reacted corresponds to the amount of STV. Calculations in titrimetry were based on a 1:0.666 (STV:KBrO3) stoichiometry and the method was found to be applicable over 3.5-10 mg range. A linear increase in absorbance with concentration of STV was observed in the spectrophotometric methods, and the Beer's law was obeyed over the concentration ranges 0.125-1.75, 1-10 and 1-9.0 µg mL-1 STV for method A, method B and method C, respectively. The methods when applied to the determination of STV in tablets and capsules were found to give satisfactory results.

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

Acta Pharmaceutica ◽

10.2478/v10007-007-0007-7 ◽

2007 ◽

Vol 57 (1) ◽

pp. 87-98 ◽

Cited By ~ 9

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.

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Use of ceric ammonium sulphate and two dyes, methyl orange and indigo carmine, in the determination of lansoprazole in pharmaceuticals

Acta Pharmaceutica ◽

10.2478/v10007-007-0017-5 ◽

2007 ◽

Vol 57 (2) ◽

pp. 211-220 ◽

Cited By ~ 7

Author(s):

Kanakapura Basavaiah ◽

Veeraiah Ramakrishna ◽

Urdigere Kumar

Keyword(s):

Methyl Orange ◽

Ammonium Sulphate ◽

Indigo Carmine ◽

Correlation Coefficients ◽

Standard Addition ◽

Fixed Amount ◽

Spectrophotometric Methods ◽

Relative Standard ◽

Bulk Drug

Use of ceric ammonium sulphate and two dyes, methyl orange and indigo carmine, in the determination of lansoprazole in pharmaceuticalsTwo spectrophotometric methods are proposed for the assay of lansoprazole (LPZ) in bulk drug and in dosage forms using ceric ammonium sulphate (CAS) and two dyes, methyl orange and indigo carmine, as reagents. The methods involve addition of a known excess of CAS to LPZ in acid medium, followed by determination of residual CAS by reacting with a fixed amount of either methyl orange, measuring the absorbance at 520 nm (method A), or indigo carmine, measuring the absorbance at 610 nm (method B). In both methods, the amount of CAS reacted corresponds to the amount of LPZ and the measured absorbance was found to increase linearly with the concentration of LPZ, which is corroborated by the correlation coefficients of 0.9979 and 0.9954 for methods A and B, respectively. The systems obey Beer's law for 0.5-7.0 μg mL-1and 0.25-3.0 μg mL-1for methods A and B, respectively. The apparent molar absorptivities were calculated to be 3.0 x 104and 4.4 x 104L mol-1cm-1for methods A and B, respectively. The limits of detection (LOD) and quantification (LOQ) were calculated to be 0.08 and 0.25 μg mL-1for method A, and 0.09 and 0.27 μg mLs-1for method B, respectively. The intra-day and inter-day precision and accuracy of the methods were evaluated according to the current ICH guidelines. Both methods were of comparable accuracy (er≤ 2 %). Also, both methods are equally precise as shown by the relative standard deviation values < 1.5%. No interference was observed from common pharmaceutical adjuvants. The accuracy of the methods was further ascertained by performing recovery studies using the standard addition method. The methods were successfully applied to the assay of LPZ in capsule preparations and the results were statistically compared with those of the literature UV-spectrophotometric method by applying Student'st-test andF-test.

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

E-Journal of Chemistry ◽

10.1155/2006/472186 ◽

2006 ◽

Vol 3 (4) ◽

pp. 242-249 ◽

Cited By ~ 2

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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