Extractive Colorimetric Method for the Determination of Dothiepin Hydrochloride and Risperidone in Pure and in Dosage Forms

Abstract

Three rapid, simple, reproducible and sensitive extractive colorimetric methods (A-C) for assaying dothiepin hydrochloride (I) and risperidone (II) in bulk sample and in dosage forms were investigated. Methods A and B are based on the formation of an ion pair complexes with methyl orange (A) and orange G (B), whereas method C depends on ternary complex formation between cobalt thiocyanate and the studied drug I or II. The optimum reaction conditions were investigated and it was observed the calibration curves resulting from the measurements of absorbance concentration relations of the extracted complexes were linear over the concentration range 0.1-12 m mg ml ؊1 for method A, 0.5-11 m mg ml ؊1 for method B, and 3.2-80 m mg ml ؊1 for method C with a relative standard deviation (RSD) of 1.17 and 1.28 for drug I and II, respectively. The molar absorptivity, Sandell sensitivity, Ringbom optimum concentration ranges, and detection and quantification limits for all complexes were calculated and evaluated at maximum wavelengths of 423, 498, and 625 nm, using methods A, B, and C, respectively. The interference from excipients commonly present in dosage forms and common degradation products was studied. The proposed methods are highly specific for the determination of drugs I and II, in their dosage forms applying the standard additions technique without any interference from common excipients. The proposed methods have been compared statistically to the reference methods and found to be simple, accurate (ttest) and reproducible (F-value).

Sensitive Method for the Quantitative Determination of Ergotamine in Tablet Dosage Form by High-Performance Liquid Chromatography Using Bromocriptine as Internal Standard

“…Other techniques for the determination of risperidone from pharmaceutical dosage form have been developed. These techniques include extractive colorimetry (8), chemiluminescence (9), capillary zone electrophoresis (10) and non-aqueous titration (11). There are numerous methods to quantify risperidone and 9-OH-risperidone enantiomers in biological fluids, including HPLC-DAD (12), HPLC with electrochemical detection (13), MEPS–LC–UV (14), LC–MS/MS (15, 16) and affinity capillary electrophoresis and H1 NMR spectroscopy (17).…”

Application of ion‐pair complexation reaction for the spectrophotometric determination of bupropion hydrochloride in pharmaceuticals

“…This technique depends on the reaction of a drug that has a basic cationic nitrogen and an anionic dye at a suitable pH, where a highly coloured ion‐pair complex is formed. Also, methyl orange (MO) has been widely used as ion‐pairing reagent for quantitative analysis of many drugs in pharmaceutical formulations 29, 31–35. However, no report dealing with the extractive spectrophotometric determination of BUPH in drug forms has appeared so far.…”

Colorimetric and Atomic Absorption Spectrometric Determination of Mucolytic Drug Ambroxol Through Ion-Pair Formation with Iron and Thiocyanate

“…Analysis of organic samples by extraction of ionpairs with acidic and basic dyestuffs using molecular spectrophotometry has been known for many years [26][27][28][29][30][31][32]. AMB has also been determined in this way using acidic dyes as ion-pairing reagents [12,[33][34][35].…”

“…However, the use of charged metal complexes allows the use of indirect atomic spectroscopic applications as well as ion-pair extractive spectrophotometry for the determination of organic compounds. The complexes formed between thiocyanate and various cations such as chromium, zinc, cobalt or iron have been widely used for positively charged analytes in pharmaceutical analysis [31,32,[36][37][38][39][40][41][42][43][44][45].…”