A batch and flow injection (FI) methods with spectrophotometric detection is proposed for determining of two of phenolic drugs: salbutamol sulphate(SLB)and pyridoxine hydrochloride(PYD) in pure and in pharmaceutical formulations. The methods utilized an oxidative-coupling reaction based upon oxidation of 2,4-dinitrophenylhydrazine (DNPH) with sodium periodate, where an electrophilic intermediate (diazonium salt of the reagent) is produced, which couples with either SLB or PYD in the presence of sodium hydroxide yielding a highly colored condensation product. The absorbance is measured after 15min at 525and515 nm for SLB and PYD respectively. Calibration graphs for both batch and FIA methods were linear over the concentration ranges of 1-

Two simple, sensitive, accurate and economic methods A and B have been developed for the quantitative estimation of vancomycin hydrochlorid (VHC) and its formulations using another two drug compounds as a coupling reagents.The proposed methods are based on a coupling reaction between VHC and diazotized procain (method A) or diazotized sulphacetamide sodium (method B) in alkaline medium to form intense yellow, water-soluble dyes that are very stable and have a maximum absorption at 447 and 439 nm for methods A and B respectively. Regression analysis of Beer’s law plots showed good correlation in the concentration ranges 1-28 and 1-45 μg ml-1 for methods A and B, respectively with a molar absorbtivity of 4.605×104 L mol-1cm-1 and 4.516

A rapid, sensitive and without extraction spectrophotometric method for determination of clonazepam (CLO) in pure and pharmaceutical dosage forms has been described. The proposed method was simply depended on charge transfer reaction between reduced CLO (n-donor) and metol (N-methyl-p-aminophenol sulfate) as a chromogenic reagent (π- acceptor). The reduced drug, with zinc and concentrated hydrochloric acid, produced a purple colored soluble charge-transfer complex with metol in the presence of sodium metaperiodate in neutral medium, which has been measured at λmax 532 nm. All the variables which affected the developed and the stability of the colored product such as concentration of reagent and oxidant, temperature and time of rea

In this study, four different spectrophotometric methods were applied for determination of cimetidine and erythromycin ethylsuccinate drugs in pure form and in their pharmaceutical preparations. The suggested methods are simple, sensitive, accurate, not time consuming and inexpensive. The results showed the following: The first method: Based on the formation of ion pair complex of each drug with bromothymol blue (BTB) as a chromogenic reagent. The formed complexes were extracted with chloroform and their absorbance values were measured at 427.5 nm for cimetidine and 416.5nm for erythromycin ethylsuccinate; against their reagents blanks. Two different methods, univariate method and multivariate method, were used to obtain the optimum condit

It is generally accepted that there are two spectrophotometric techniques for quantifying ceftazidime (CFT) in bulk medications and pharmaceutical formulations.  The methods  are described as simple, sensitive, selective, accurate and efficient techniques. The first method used an alkaline medium to convert ceftazidime to its diazonium salt, which is then combined with the 1-Naphthol (1-NPT) and 2-Naphthol (2-NPT) reagents. The azo dye that was produced brown  and red in color with absorption intensities of ƛmax 585 and 545nm respectively. Beer's law was followed in terms of concentration ranging from  (3-40) µg .ml^-1 For (CFT-1-NPT) and (CFT-2-NPT), the detection limits were 1.0096 and 0.8017 µg.ml^-1, respec

A simple and rapid spectrophotometric method for the determination of sulphite SO3-2 is described. The method is based on the rapid reduction of known amount of chromate CrO4-2 in the presence of sulphite in acidic medium of 2N H2SO4. The amount of excess of chromate was measured after it reactions with 1,5-diphenylcarbazide which finally gives a pink-violet, water soluble and stable complex, which exhibit a maximum absorption at 542 nm. Beer's law was obeyed in the concentration range from 0.004-6.0 µg of sulphite in a final volume of 25 ml with a molar absorbtivity of 4.64×104 l.mol-1.cm-1, Sandal's sensitivity index of 0.001724 ?g .cm-2 and relative standard deviation of ±0.55 - ±0.83 depending on the concentration level. The present

Two simple, sensitive, accurate and economic methods A and B have been developed for the quantitative estimation of vancomycin hydrochlorid (VHC) and its formulations using another two drug compounds as a coupling reagents.The proposed methods are based on a coupling reaction between VHC and diazotized procain (method A) or diazotized sulphacetamide sodium (method B) in alkaline medium to form intense yellow, water-soluble dyes that are very stable and have a maximum absorption at 447 and 439 nm for methods A and B respectively. Regression analysis of Beer’s law plots showed good correlation in the concentration ranges 1-28 and 1-45 μg ml-1 for methods A and B, respectively with a molar absorbtivity of 4.605×104 L mol-1cm-1 and 4.516

A simple, accurate, precise, rapid, economical and a high sensitive spectrophotometric method has been developed for the determination of tadalafil in pharmaceutical preparations and industrial wastewater samples, which shows a maximum absorbance at 204 nm in 1:1 ethanol-water. Beer's law was obeyed in the range of 1-7?g/ mL ,with molar absorptivity and Sandell ? s sensitivity of 0.783x105l/mol.cm and 4.97 ng/cm2respectively, relative standard deviation of the method was less than 1.7%, and accuracy (average recovery %) was 100 ± 0. 13. The limits of detection and quantitation are 0.18 and 0.54 µg .ml-1, respectively. The method was successfully applied to the determination of tadalafil in some pharmaceutical formulations

Flow-injection (FI) spectrophotometric method has been developed for the analysis of thymol in pharmaceutical preparations. The method is based on organic coupling reaction between thymol and 4-amino antipyrine in the presence of alkaline medium to form an intense stable red color complex with copper nitrate that has a maximum absorption at 490 nm. Optimum conditions for determination of the drug was investigated .The calibration graph was linear over the range of 5-500 µg.ml-1 of thymol . The limit of detection (LOD) and limit of quantification (LOQ) were 1.81 ?g mL-1 and 3.60 ?g mL-1 respectively .The proposed method was applied satisfactorily to the determination of thymol in mouth wash preparations. The procedure is characterized by