OALib Journal期刊

ISSN: 2333-9721



匹配条件: “Basavaiah” ,找到相关结果约103条。
NAGARAJU RAJENDRAPRASAD,Kanakapura Basavaiah,Kanakapura Basavaiah Vinay
Chemical Industry and Chemical Engineering Quarterly , 2011,
Abstract: Quetiapine fumarate (QTF) is an antipsychotic drug belonging to the benzisoxazole derivatives indicated for the treatment of schizophrenia. A sensitive and selective method based on dichloromethane-extractable ion-pair of QTF with calmagite (CGT), which exhibited an absorption maximum at 490 nm, is described. At this wavelength, Beer’s law is obeyed over the concentration range of 3.0–30.0 μg ml-1. The apparent molar absorptivity, limit of detection (LOD) and quantitation (LOQ) values are 1.32×104 l mol-1 cm-1, 0.27 and 0.81 μg ml-1, respectively. The reaction is extremely rapid at room temperature and the absorbance values remain unchanged up to 19 h. The precision results, expressed as intra-day and inter-day relative standard deviation values, are satisfactory (RSD ≤ 2.2%). The accuracy is satisfactory as well (RE ≤ 2.44%). The method was successfully applied to the determination of QTF in pharmaceuticals and spiked human urine with satisfactory results. No interference was observed from common pharmaceutical adjuvants in tablets. Statistical comparison of the results with the official method showed an excellent agreement and indicated no significant difference in precision.
Microtitrimetric determination of a drug content of pharmaceuticals containing olanzapine in non-aqueous medium
Chemical Industry and Chemical Engineering Quarterly , 2009,
Abstract: Two simple, rapid, reliable and cost-effective methods based on titrimetry in non-aqueous medium are described for the determination of olanzapine in pharmaceuticals. In these methods, the drug dissolved in the glacial acetic acid was titrated with the acetous perchloric acid with visual and potentiometric end point detection, crystal violet being used as the indicator for visual titration. The methods are applicable over 1-15 mg range of olanzapine. The procedures were applied to determine olanzapine in pharmaceutical products and the results were found to be in a good agreement with those obtained by the reference method. Associated pharmaceutical materials did not interfere. The precision results, expressed by inter-day and intra-day relative standard deviation values, were satisfactory, higher than 2%. The accuracy was satisfactory as well. The methods proved to be suitable for the analysis of olanzapine in bulk drug and in tablets. The accuracy and reliability of the methods were further ascertained by recovery studies via a standard addition technique with percent recoveries in the range 97.51-103.7% with a standard deviation of less than 2%.
Utility of N-Bromosuccinimide for the Titrimetric and Spectrophotometric Determination of Famotidine in Pharmaceutical Formulations
O. Zenita,K. Basavaiah
International Journal of Analytical Chemistry , 2011, DOI: 10.1155/2011/581372
Abstract: Two titrimetric and two spectrophotometric methods are described for the assay of famotidine (FMT) in tablets using N-bromosuccinimide (NBS). The first titrimetric method is direct in which FMT is titrated directly with NBS in HCl medium using methyl orange as indicator (method A). The remaining three methods are indirect in which the unreacted NBS is determined after the complete reaction between FMT and NBS by iodometric back titration (method B) or by reacting with a fixed amount of either indigo carmine (method C) or neutral red (method D). The method A and method B are applicable over the range of 2–9?mg and 1–7?mg, respectively. In spectrophotometric methods, Beer's law is obeyed over the concentration ranges of 0.75–6.0? g? (method C) and 0.3–3.0? g? (method D). The applicability of the developed methods was demonstrated by the determination of FMT in pure drug as well as in tablets. 1. Introduction Famotidine (FMT), 3-[2-(diaminomethyleneamino)thiazol-4-ylmethylthio]-N-sulfamoylpropionamidine (Figure 1), is a histamine H2-receptor antagonist (H2-RA). It is widely used for the treatment of duodenal ulcers, benign gastric ulcer, reflux oesophagitis, and hyperacid secretory conditions. FMT is official in both the British Pharmacopoeia (BP) [1] and the United States Pharmacopoeia (USP) [2]. The BP [1] recommends thin-layer chromatography using a silica gel F254 precoated plate (Fischer Silica Gel GF plates are suitable) and a mixture of 2 volumes of 13.5?M ammonia, 20 volumes of toluene, 25 volumes of methanol, and 40 volumes of ethyl acetate as the mobile phase. The USP [2] recommends a potentiometric nonaqueous method for the determination of FMT using perchloric acid as the titrant and a HPLC method using a mixture of acetate buffer of pH 6?:?acetonitrile (93?:?7) as a mobile phase with UV detection at 275?nm. Figure 1: Structure of famotidine. Several procedures have been reported in the literature for the analysis of FMT. The reported methods include HPLC [3–5], HPTLC [6, 7], capillary electrophoresis [8], potentiometry [9], differential pulse voltammetry [10], spectrofluorimetry [11, 12], polarography [13], and UV-spectrophotometry [14]. Some of these methods involve several manipulation steps, which are not simple for routine analysis of pharmaceutical formulations and need sophisticated instruments. Titrimetry and visible spectrophotometry may serve as useful alternatives to many of the aforesaid sophisticated techniques because of their cost effectiveness, ease of operation, sensitivity, remarkable accuracy and precision, and wide
Simple and practicable methods for the determination of astemizole in pharmaceuticals using bromate-bromide and two dyes
Nagegowda, Paregowda;Basavaiah, Kanakapura;
Journal of the Brazilian Chemical Society , 2005, DOI: 10.1590/S0103-50532005000500022
Abstract: one titrimetric and two spectrophotometric methods, which are simple and sensitive, are described for the determination of astemizole (ast) in bulk drug and formulations. the methods use bromate-bromide mixture and two dyes, methyl orange and indigo carmine. in titrimetry (method a), astemizole is treated with a known excess of bromate-bromide mixture in acid medium and after the bromination reaction is ensured to be complete, the residual bromine is back-titrated iodometrically. in spectrophotometric methods, the excess of bromine is estimated by treating it with a fixed amount of either methyl orange (method b) or indigo carmine (method c) and measuring the change in absorbance either at 520 or 610 nm. in all the methods, the amount of bromate reacted corresponds to the drug content. titrimetric method is applicable over 4-16 mg range and the calculations are based on a 1:0.666 (ast: bromate) reacting ratio. in spectrophotometry, the calibration graph is found to be linear over 0.5-4.0 μg ml-1 (method b) and 1.25 12.5 μg ml-1 (method c) with molar absorptivity values of 6.6 x 104 l mol-1 cm-1 and 2.1 x 104 l mol-1 cm-1, respectively. the limits of detection and quantification are reported for methods b and c. the statistical evaluation of the methods was examined by determining intra-day and inter-day precision. the methods were applied to the determination of ast in tablets and syrups and the results were found to agree well with the label claim. the accuracy and reliability of the methods were further ascertained by parallel determination by a reference method and by calculating the student's t-value and f-value at the 95% confidence level, and by recovery studies using standard addition technique.
Investigation and Optimisation of the Use of Spectrophotometry for the Assay of Simvastatin with in situ Bromine and Three Dyes as Reagents
Basavaiah, Kanakapura;Tharpa, Kalsang;
Journal of the Mexican Chemical Society , 2008,
Abstract: three simple and sensitive spectrophotometric methods are described for the determination of simvastatin (smt) in bulk drug and in tablets using bromate-bromide as the bromination reagent in acid medium, and three dyes as subsidiary reagents. all the three methods are based on the bromination of smt by a known excess of in situ generated bromine followed by determination of unreacted bromine by reacting with a fixed amount of methyl orange (method a), indigo carmine (method b) or meta-cresol purple (method c) and measuring the absorbance at 510, 610 or 540 nm. in all the methods, the amount of bromine reacted corresponds to the amount of smt. the experimental conditions for the assay have been optimized. in all the methods, the absorbance is found to increase linearly with the concentration of smt at the respective wavelengths. beer's law is obeyed over the ranges 0.5-3.0, 2.5-15.0 and 2.5-15.0 |ig ml-1 for method a, method b and method c, respectively and the respective molar absorptivity values are 1.0 ×10 5, 2.3 ×104 and 2.1 ×104 l mol-1 cm-1. the limits of detection and quantification are reported for all the methods. the performance of the methods was validated according to the present ich guidelines. the methods gave similar results in terms of precision and accuracy. the repeatability and intermediate precision, expressed by the rsd was better than 2%. the accuracy of the methods expressed as relative error was satisfactory. the proposed methods were applied to the analysis of tablet form of smt and the results tallied well with the label claim. no interference was observed from the concomitant substances normally added to tablets. the results were statistically compared with those of a literature method by applying the student's t-test and f-test. the accuracy and validity of the methods were further ascertained by performing recovery studies via spike method and standard-addition method.
Determination of olanzapine by spectrophotometry using permanganate
Rajendraprasad, Nagaraju;Basavaiah, Kanakapura;
Brazilian Journal of Pharmaceutical Sciences , 2009, DOI: 10.1590/S1984-82502009000300020
Abstract: two new spectrophotometric methods using permanganate as the oxidimetric reagent for the determination of olanzapine (olp) were developed and validated as per the current ich guidelines. the methods involved the addition of known excess of permanganate to olp in either acid or alkaline medium followed by the determination of unreacted permanganate at 550 nm (method a) or bluish-green color of manganate at 610 nm (method b). the decrease in absorbance in method a or increase in absorbance in method b as a function of concentration of olp was measured and related to olp concentration. under optimized conditions, beer's law was obeyed over the ranges 2.0 to 20 and 1.0 to 10 μg ml-1 in method a and method b, respectively. the calculated molar absorptivity values were 1.34 x 104 and 2.54 x 104 l mol-1cm-1 for method a and method b respectively, and the respective sandell sensitivities were 0.0233 and 0.0123 μg cm-2. the lod and loq for method a were calculated to be 0.37 and 1.13 μg ml-1and the corresponding values for method b were 0.16 and 0.48 μg ml-1. intermediate precision, expressed as rsd was in the range 0.51 to 2.66 %, and accuracy, expressed as relative error ranged from 0.79 to 2.24 %. the proposed methods were successfully applied to the assay of olp in commercial tablets with mean percentage recoveries of 102 ±1.59 % (method a) and 101 ±1.53 % (method b). the accuracy and reliability of the methods were further confirmed by performing recovery tests via standard addition procedure.
Spectrophotometric determination of famotidine using sulphonphthalein dyes
Basavaiah, Kanakapura;Zenita, Okram;
Química Nova , 2011, DOI: 10.1590/S0100-40422011000500002
Abstract: four new extraction-free spectrophotometric methods have been established for the quantitation of famotidine (fmt). the methods are based on the formation of yellow ion-pair complexes between fmt and four sulphonphthalein dyes viz., bromothymol blue (method a), bromophenol blue (method b), bromocresol purple (method c) and bromocresol green (method d) in dioxane or acetone medium. the experimental variables such as reagent concentration, solvent medium and reaction time have been carefully optimized to achieve the highest sensitivity. the proposed methods were applied successfully to the determination of famotidine in tablets with good accuracy and precision and without interferences from common excipients. the results obtained by the proposed methods were compared favorably with those of the reference method.
Investigation and Optimisation of the Use of Spectrophotometry for the Assay of Simvastatin with in situ Bromine and Three Dyes as Reagents
Kanakapura Basavaiah,Kalsang Tharpa
Revista de la Sociedad Química de México , 2008,
Abstract: Se describen tres métodos espectrofotométricos simples y sensibles para la determinación de simvastatina (STM) en el medicamento a granel y en comprimidos usando bromato-bromuro como el reactivo de bromación en medio ácido, y tres colorantes como reactivos subsidiarios. Los tres métodos se basan en la bromación de STM por un exceso conocido de bromo generado in situ, seguida por la determinación del bromo que no reacciona, mediante una reacción con una cantidad fija de naranja de metilo (método A), carmín índigo (método B) o púrpura de metacresol (método C), y midiendo la absorbancia a 510, 610 o 540 nm. En todos los métodos, la cantidad de bromo que reacciona corresponde a la cantidad de STM. Las condiciones experimentales para la determinación fueron optimizadas. En todos los métodos, se encontró que la absorbancia se incrementa linealmente con la concentración de SMT a las respectivas longitudes de onda. La ley de Beer se cumple en los intervalos de 0.5-3.0, 2.5-15.0 y 2.5-15.0 g mL-1 para el método A, el método B y el método C, respectivamente, y los valores de los respectivos coeficientes de absortividad molar son 1.0 X 10 5, 2.3 X 104 y 2.1 X 104 l mol-1 cm-1. Los límites de detección y cuantificación se reportan para cada método. El desempe o de los métodos se validó de acuerdo con los procedimientos actuales ICH. Los métodos dieron resultados semejantes en términos de precisión y exactitud. La repetibilidad y la precisión intermedia, expresadas por el RSD fueron mejor que el 2%. La exactitud de los métodos, expresada como error relativo, fue satisfactoria. Los métodos propuestos fueron aplicados satisfactoriamente al análisis de STM en comprimidos y los resultados correspondieron con lo reportado en el marbete. No se observaron interferencias de las substancias concomitantes normalmente a adidas a los comprimidos. Los resultados fueron estadísticamente comparados con otros métodos publicados en la literatura aplicando la prueba t y F de Student. La exactitud y la validez de los métodos fueron adicionalmente comprobadas a través de la realización de estudios de recuperación de muestras fortificadas y el método de adiciones patrón.
Chemical Industry and Chemical Engineering Quarterly , 2008,
Abstract: Two simple and sensitive spectrophotometric methods have been developed for the determination of simvastatin (SMT) in pure form and in tablets using insitu generated bromine, and p-phenylenediamine (PPDA) or o-dianisidine (ODA) as reagents. The methods are based on the bromination of SMT by a measured excess of in situ bromine in acid medium followed by the determination of unreacted bromine by reacting with PPDA and measuring the resulting red colour at 510 nm (method A) or reacting with ODA and measuring the absorbance at 470 nm (method B). The conditions for the assay have been optimized. Beer’s law is obeyed over the concentration ranges 20-120 and 2- -12 μg/ml for method A and method B, respectively. The calculated molar absorbtivities are 2.24×103 and 1.91×104 dm3 mol-1 cm-1 for the method A and the method B, respectively; 0.1868 and 0.0115 μg/cm2 being the corresponding Sandell sensitivities. The LOD and LOQ for method A are found to be 2.96 and 8.97 μg/ml, and the respective values for method B are 0.14 and 0.42 μg/ml. The intra-day and inter-day precision and accuracies were checked. The assay precision was less than 5 % CV and the accuracy was 97.38-103.4 %. The methods were used for the determination of SMT in tablets. No interference from the excipients added to tablets was found. The accuracy and validity of the methods were further ascertained by recovery studies via the standard addition technique.
Use of Two Sulfonphthalein Dyes for the Sensitive and Selective Extraction-Free Spectrophotometric Assay of Albendazole in Bulk Drug and in Tablets
Nagaraju Swamy,Kanakapura Basavaiah
ISRN Analytical Chemistry , 2013, DOI: 10.1155/2013/734027
Abstract: Albendazole (ALB) is a potent benzimidazole anthelmintic used in the treatment of human intestinal helmintiasis as well as of hytatid cysts and neurocysticercosis. Two rapid, simple, sensitive, and selective spectrophotometric methods are presented for the determination of ALB in pharmaceuticals. The methods are based on the formation of dichloromethane soluble 1?:?1 ion-pair complexes (ALB?:?dye) formed between ALB and sulfonphthalein dyes, bromophenol blue BPB, (method A) and bromothymol blue BTB, (method B). The complexes formed were measured directly (without extraction) at 445?nm (method A) and 460?nm (method B). The experimental conditions were optimized and the systems obey Beer’s law for 1.5–21.0 and 2.0–32.0?μg?mL?1 ALB for method A and method B respectively. The molar absorptivity and Sandell's sensitivity were calculated to be ?L?mol?1?cm?1 and 0.0209?ng?cm?2, and ?L?mol?1?cm?1 and 0.0350?ng?cm?2 using BPB and BTB, respectively. The limits of detection and quantification were calculated to be 0.01 and 0.03, and 0.16, and 0.49?μg mL?1 using BPB and BTB, respectively. The relative standard values for intra-day and inter-day precision were less than 3%, and the accuracy was better than 3% for both methods. 1. Introduction Albendazole (ALB), chemically known as methyl-5-(propyl thio)-2-yl benzimidazole methyl carbamate [1], is widely used as an anthelmintic having a wide spectrum of activity [2]. The drug is official in British Pharmacopoeia [3], which describes a potentiometric titration with perchloric acid in formic acid-acetic acid medium. Quantitative determination of ALB in dosage forms has received wide attention and several methods have been reported and include titrimetry in nonaqueous medium [4, 5], redox titrimetry [6–12], UV spectrophotometry [13–17], spectrofluorimetry [18, 19], voltammetry [20–22], high performance liquid chromatography [23–27], and high performance thin layer chromatography [28, 29]. Several visible spectrophotometric methods, both direct and indirect, are found in the literature for the determination of ALB in pharmaceuticals. Basavaiah et al. [30] in their methods treated ALB with a known excess of NBS in HCl medium, and the unreacted oxidant was reduced by iron(II) and the resulting iron(III) was complexed with thiocyanate or tiron offering two sensitive methods. Two more indirect methods [31] involving NBS-metol-sulfanilamide and NBS-celesteine blue as chromogenic systems have been proposed by Sastry et al. Several other reaction schemes involving chloramine-T-methyl orange or indigocarmine [6],

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