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Ramdas, C.
- Visible Spectrophotometric Methods Development for Quantification of Racecadotril in Commercial Formulations
Authors
1 Department of Engineering Chemistry, AU College of Engineering (A), Andhra University, Visakhapatnam-530003, AP, IN
2 Department of Chemistry, Maharaja's College (Aided & Autonomous), Vizianagaram-535002, AP, IN
3 M/S Tychy Industries, R&D Division, Hyderabad (AP), IN
Source
Research Journal of Pharmaceutical Dosage Form and Technology, Vol 6, No 3 (2014), Pagination: 183-187Abstract
Three direct, simple and sensitive visible spectrophotometric methods (M1,M2 and M3) are described for the assay of Racecadotril in pure and solid dosage forms. The method M1 is based on the formation of colored molecular complex with sodium nitroprusside in presence of acetaldehyde under alkaline conditions and exhibits λ max at 560nm. The method M2 involves oxidative coupling of drug with brucine in presence of sodium meta periodate and purple red colored species is formed and exhibits absorption maxima at 520nm. The method M3 is based on the formation of yellowish brown colored species by the drug with Folin reagent and exhibits absorption maxima at 450nm.Regression analysis of Beer-Lambert plots showed good correlation in the concentration ranges (8.0-40) μg/ml for methods M1, M2 and (20-60) μg/ml for method M3 respectively. The proposed methods are applied to commercial available formulations and the results are statistically compared with those obtained by the reported UV reference method (in methanol, λ max at 231nm) and validated by recovery studies. The results are found satisfactory and reproducible. These methods are applied successfully for the estimation of the Racecadotril in the presence of other ingredients that are usually present in dosage forms.Keywords
Inner Molecular complex, Aromatic Nucleophillic substitution, Oxidative coupling, Statistical analysis, Regression equation.
- Ion Association Methods Development for the Assay of Venlafaxine Hydrochloride Using Two Acidic Dyes
Authors
1 Department of Engineering Chemistry, AU College of Engineering (A), Andhra University, Visakhapatnam-530003 Andhra Pradesh, IN
2 Department of Chemistry, Maharajah’s College (Aided and Autonomous), Vizianagaram-535002 (AP), IN
3 Tychy Industries, R and D Division, Hyderabad-AP, IN
Source
Asian Journal of Research in Chemistry, Vol 5, No 1 (2012), Pagination: 74-78Abstract
Two simple, rapid and sensitive extractive visible spectrophotometric methods (A and B) for the assay of venlafaxine hydrochloride in pure and solid dosage forms based on the formation of colored chloroform soluble ion - association associates under specified experimental conditions are described. Two dyes namely acidic dyes Naphthalene Blue 12BR (NB12BR, method A) and Bromo Cresol Purple (BCP, method B) are utilized. The extracts of the ion-associates exhibit absorption maxima at 620.5 nm and 430 nm for methods A and B respectively. Regression analysis of Beer- Lambert plots showed good correlation in the concentration ranges (4.0 -12.0) μg/ml for method A, (8.0-40.0) μg/ml for method B respectively. The proposed methods are applied to commercial available tablets and the results are statistically compared with those obtained by the UV reference method and validated by recovery studies. The results are found satisfactory and reproducible. These methods are applied successfully for the estimation of the venlafaxine hydrochloride in the presence of other ingredients that are usually present in dosage forms. These methods offer the advantages of rapidity, simplicity and sensitivity and normal cost and can be easily applied to resource-poor settings without the need for expensive instrumentation and reagents.