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Titrimetric and spectrophotometric assay of oxcarbazepine in pharmaceuticals using N-bromosuccinimide and bromopyrogallol red.

Rajendraprasad N, Basavaiah K, Vinay KB - Int J Anal Chem (2011)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of Mysore, Manasagangothri, Mysore-570 006, Karnataka, India.

ABSTRACT
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 of 2.52 × 10(4) L mol(-1) cm(-1) is 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.

No MeSH data available.


Tentative reaction pathway for the formation of yellow coloured bromo-derivative of BPR (method B).
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sch3: Tentative reaction pathway for the formation of yellow coloured bromo-derivative of BPR (method B).

Mentions: In the proposed titrimetric method, OXC is directly titrated with NBS in sulphuric acid medium. The reaction between OXC and NBS was found to occur in 1 : 1 (drug : NBS) stoichiometric ratio, and all the calculations are based on this fact. Using 0.01 M NBS, 6–18 mg of OXC was conveniently determined. In spectrophotometry, a known excess of NBS was treated with OXC and after the reaction between OXC and NBS ensured to be complete, the unreacted NBS was reacted with a fixed concentration of BPR followed by the measurement of residual dye at 460 nm (Figure 1 and Scheme 3).


Titrimetric and spectrophotometric assay of oxcarbazepine in pharmaceuticals using N-bromosuccinimide and bromopyrogallol red.

Rajendraprasad N, Basavaiah K, Vinay KB - Int J Anal Chem (2011)

Tentative reaction pathway for the formation of yellow coloured bromo-derivative of BPR (method B).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3139870&req=5

sch3: Tentative reaction pathway for the formation of yellow coloured bromo-derivative of BPR (method B).
Mentions: In the proposed titrimetric method, OXC is directly titrated with NBS in sulphuric acid medium. The reaction between OXC and NBS was found to occur in 1 : 1 (drug : NBS) stoichiometric ratio, and all the calculations are based on this fact. Using 0.01 M NBS, 6–18 mg of OXC was conveniently determined. In spectrophotometry, a known excess of NBS was treated with OXC and after the reaction between OXC and NBS ensured to be complete, the unreacted NBS was reacted with a fixed concentration of BPR followed by the measurement of residual dye at 460 nm (Figure 1 and Scheme 3).

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, University of Mysore, Manasagangothri, Mysore-570 006, Karnataka, India.

ABSTRACT
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 of 2.52 × 10(4) L mol(-1) cm(-1) is 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.

No MeSH data available.