Two facile approaches based on association complex with erythrosine-B for nano-level analysis of duloxetine: application to content uniformity

Duloxetine is an antidepressant that exhibits its action by preventing the reuptake of serotonin and norepinephrine by neurons. In this analytical study, we developed two facile, sensitive methods for duloxetine analysis. Both methods rely on the formation of binary association complex between erythrosine-B and duloxetine in an acidic medium using spectrofluorimetric and resonance Rayleigh scattering (RRS) techniques. Spectrofluorimetric method simply uses the quenching property of the formed complex on the native fluorescence of erythrosine-B at an emission wavelength of 557.2 nm ( λ ex = 528.6), while RRS is based on detecting the enhancement in the RRS signal at 357.2 nm. The proposed methods have been validated according to the International Conference on Harmonization guidelines. The approaches provide linear assay of duloxetine hydrochloride over 0.1–2.4 µg ml −1 and 0.2–2.0 µg ml −1 for spectrofluorimetric and RRS methods, respectively. Variables affecting methods and complex formation were studied and optimized. The limit of detection values were 0.03 and 0.056 µg ml −1 for spectrofluorimetric and RRS methods, respectively. Both approaches were applied with acceptable results for formulation analysis and evaluation of cymbatex capsule content uniformity.

Studying the quenching resulted from the formation of an association complex between olsalazine or sulfasalazine with acriflavine

We report the detection and quantification of important ulcerative colitis drugs olsalazine (OLS) and sulfasalazine (SUL) by the spectrofluorometric method. The proposed method was optimized and validated by using the quenching effect on the acriflavine fluorescence. The method was applied on the detection and quantification of OLS and SUL under optimized conditions showing the calibration curves were linear (range: 1.0–10.0 µg ml −1 ), with correlation coefficients R 2 of 0.9999 for both drugs. The limits of detection (LOD) and quantification (LOQ) were 53 and 104 ng ml −1 for the OLS and 160 and 315 ng ml −1 for the SUL. This method permitted the analysis of OLS and SUL in their pure and pharmaceutical forms. The proposed spectrofluorimetric method was also evaluated against ‘green’ criteria and all the experimental results make it an eco-friendly and safe method for the detection of OLS and SUL.

Spectrophptometric Analysis of Clathromycin with Tpooo, Ars and WFB

One simple and sensitive procedure (simple spectrophotometric method) for the assay of drug clarithromycin in pure form and formulations. This method involves the formation of ion-association complex between CAM and the TPOOO, ARS and WFB. In order to establish the optimum conditions necessary for rapid and quantitative formation of coloured product with maximum stability and sensitivity, the author performed experiments by measuring the absorbance at λmax 480nm,420nm and580nm of respective series of solutions, varying one and fixing the other parameters in each case such as type, volume and concentration of acid, organic solvent used for extraction, ratio of organic phase to aqueous phase during extraction, shaking time and temperature. The variable parameters were optimized. The results were statistically validated.

Cloud point extraction for separation, preconcentration and determination zinc (ii) in different pharmaceutical samples

Joining solvent extraction with cloud point extraction methods obtained a susceptible method for separation, pre-concentration, extraction and categorization of Zn (II), after forming an ion-pair association complex between Zn+2 and 4-(3-methyl phenyl azo)-4,5- diphenyl imidazole (MPADPI) with wavelength for maximum absorbance λmax.=496 Nm. This study shows optimum conditions for the formation and exaction ion-pair association complex under pH=9 and 0.5 mL Tritonx-100, 1×10-4 M (MPADPI) and heating at 80 Co for 20 minutes so that this study involved the effect of electrolyte and interferences along with the spectrophotometric determination of Zinc (II) in diverse samples.

Determination of Satranidazole through Ion-Associative Complex Reaction

A simple, selective, accurate and low-cost spectrophotometric method has been described for determination of satranidazole in bulk and pharmaceutical formulations. The developed method involves the formation of chloroform extractable colored ion-association complex of satranidazole with Tropaeolin OOO (TPooo). The extracted colored complex showed absorbance maximum at wavelength 484 nm and obeying Beer′s law in the concentration 4-20 μg mL-1 with the correlation coeffiecent of 0.9998. The results of statistical analysis of the proposed method reveals high accuracy and good precession. Thus, the proposed method can be used commercially for the determination of satranidazole in bulk and pharmaceutical formulations.