Studies on the development of spectrophotometric method for the determination of haloperidol in pharmaceutical preparations

A spectrophotometric method based on the formation of ion-pair complex between haloperidol and eriochrome black T (EBT) at pH 1.85 has been described. The formed complex was extracted quantitatively into chloroform and measured at 510 nm. Infra red (IR) studies were performed to confirm the formation of ion-pair complex. Beer's law was obeyed in the concentration range of 2.0-9.0 µg mL-1 with molar absorptivity of 2.67 × 10(4) L mol-1 cm-1. The detection limit was found to be 0.18 µg mL-1. Statistical comparison of the results of the proposed method with those of the reference method shows excellent agreement and indicates no significant difference in accuracy and precision

Sorption studies of some metal ions on zir-conium(IV) iodomolybdate

349-350Distribution coefficients of a large number of metal ions on zirconium(IV) iodomolybdate have been determined as a function of concentration of formic acid. On the basis of Kd values, Hg2+ has been separated from numerous metal ions

Analytical techniques in pharmaceutical analysis: A review

AbstractThe development of the pharmaceuticals brought a revolution in human health. These pharmaceuticals would serve their intent only if they are free from impurities and are administered in an appropriate amount. To make drugs serve their purpose various chemical and instrumental methods were developed at regular intervals which are involved in the estimation of drugs. These pharmaceuticals may develop impurities at various stages of their development, transportation and storage which makes the pharmaceutical risky to be administered thus they must be detected and quantitated. For this analytical instrumentation and methods play an important role. This review highlights the role of the analytical instrumentation and the analytical methods in assessing the quality of the drugs. The review highlights a variety of analytical techniques such as titrimetric, chromatographic, spectroscopic, electrophoretic, and electrochemical and their corresponding methods that have been applied in the analysis of pharmaceuticals

Osjetljiva kinetička spektrofotometrijska metoda za određivanje kaptoprila

A simple and sensitive kinetic spectrophotometric method has been developed. The method is based on the reduction of Fe(III) with captopril. Fe(II) then reacts with potassium ferricyanide, resulting in the formation of a blue product. The reaction is followed spectrophotometrically by measuring the rate of change of absorbance at 730 nm. Thus, 1.23 × 10-3 mol L-1 FeCl3 and 3.04 × 10-4 mol L-1 potassium ferricyanide were used as optimum values for maximum concentration of captopril in the calibration graph. The initial rate is utilized for constructing the calibration graph, which was found to be linear in the range 4.60 × 10–6–5.06 × 10–5 mol L-1; detection limit is 1.99 × 10–7 mol L-1. The proposed method has been validated; the mean recovery ranges from 99.8–101.4% with RSD < 2%. Common excipients do not interfere with the determination. The point and interval hypotheses tests have been performed and confirmed that there is no significant difference between the proposed method and conventional spectrophotometric method. The experimental true bias of all samples is lower than ± 2.0%. The proposed method has been applied to the determination of captopril in bulk and dosage forms.Razvijena je jednostavna osjetljiva kinetička spektrofotometrijska metoda za određivanje kaptoprila. Metoda se temelji na redukciji Fe(III) u Fe(II) koji zatim s kalijevim fericijanidom daje plavo obojeni produkt. Nastajanje produkta praćeno je spektrofotometrijski na valnoj duljini 730 nm. Optimalne koncentracije FeCl3 i potassium ferricyanida bile su 1,23 × 10-3 mol L-1, odnosno 3,04 × 10-4 mol L-1. Početna brzina upotrebljena je za izradu baždarnog pravca. Linearnost je postignuta u koncentracijskom području od 4,60 × 10–6 do 5,06 × 10–5 mol L-1; granica detekcije bila je 1,99 × 10–7 mol L-1. Predložena metoda je validirana. Srednja vrijednost analitičkog povrata iznosila je 99,8–101,4% uz RSD < 2%. Uobičajeni ekscipiensi nisu smetali određivanju. Ispitivanja hipoteze točke i intervala potvrdila su da nema značajne razlike između predložene metode i opisane spektrofotometrijske metode. Stvarna eksperimentalna pogreška za sve uzorke bila je manja od ± 2%. Opisana metoda primijenjena je za određivanje kaptoprila kao čiste supstancije i u ljekovitom pripravku

Fractal-like kinetics for adsorption of Pb (II) on graphene oxide/hydrous zirconium oxide/crosslinked starch bio-composite: Application of Taguchi approach for optimization

This study deals with the decontamination of Pb (II) from aqueous environment using graphene oxide/hydrous zirconium oxide/crosslinked starch bio-composite (GZS-BC). Various instrumental techniques were used to characterize the GZS-BC. The main factors of Pb (II) sorption were optimized by Taguchi method. Under optimum conditions, (adsorbent dose: 40 mg, contact time: 180 min and initial Pb (II) concentration: 50 mg/L) maximum removal efficiency (98.50%) was achieved at pH 6. Various isotherm models were tested to fit the adsorption data and Freundlich isotherm model was the best fit model with high R2 values (0.9977–0.9983) and low values of χ2 (0.01–0.02) and APE (0.90–1.14). The kinetic data were investigated using classical and fractal-like kinetic equations. The fractal-like mixed 1,2-order kinetic model was the best fit model which pointed towards heterogeneous surface of GZS-BC with more than one type of sorption sites. Thermodynamic study shows that Pb (II) sorption onto GZS-BC was spontaneous and endothermic in nature. The values of ΔG° indicated that physisorption together with chemisorption was responsible for uptake of Pb (II).The authors are highly thankful to Department of Chemistry, AMU assisted through UGC DRS-SAP, DST-PURSE and DST-FIST programs for providing necessary facilities. The authors extend their sincere appreciation to the Researchers Supporting Project Number (RSP2023R266) King Saud University, Riyadh, Saudi Arabia for the support.Publicad

Spectrofluorimetric determination of doxepin hydrochloride in commercial dosage forms via ion pair complexation with alizarin red S

A simple and sensitive spectrofluorimetric method has been developed for the determination of doxepin hydrochloride in pharmaceutical preparations. It is based on the formation of ion-pair complex between doxepin and alizarin red S at pH 3.09. The ion pair complex was extracted in dichloromethane and the fluorescence intensity was measured at 560 nm after excitation at 490 nm. The optimum conditions for determination were also investigated. The linear range and detection limit were found to be 2–14 and 0.55 μg/ml, respectively. The method has been successfully applied for the analysis of drug in commercial dosage forms. No interference was observed from common pharmaceutical adjuvant. Statistical comparison of the results obtained by the proposed method with that of the reference method shows excellent agreement and indicates no significant difference in accuracy and precision