A spectrophotometric method has been proposed for the determination of two drugs containing phenol group [phenylephrine hydrochloride (PHP) and salbutamol sulphate (SLB)] in pharmaceutical dosage forms. The method is based on the diazotization reaction of metoclopramide hydrochloride (MCP) and coupling of the diazotized reagent with drugs in alkaline medium to give intense orange colored product (?max at 470 nm for each of PHP and SLB). Variable parameters such as temperature, reaction time and concentration of the reactants have been analyzed and optimized. Under the proposed optimum condition, Beer’s law was obeyed in the concentration range of 1-32 and 1-14 ?g mL-1 for PHP and SLB, respectively. The limit of detection (LOD) and l

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

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

Nitroso-R-salt is proposed as a sensitive spectrophotometric reagent for the determination of paracetamol in aqueous solution. The method is based on the reaction of paracetamol with iron(III) and subsequent reaction with nitroso-R-salt to yield a green colored complex with maximum absorption at 720 nm. Optimization of the experimental conditions was described. The calibration graph was linear in the concentration range of 0.1 – 2.0 ?g mL-1 paracetamol with a molar absorptivity of 6.9 × 104 L mol-1 cm-1. The method was successfully applied to the determination of paracetamol in pharmaceutical preparations without any interference from common excipients. The method has been statistically evaluated with British Pharmacopoeia method a

Two methods have been applied for the spectrophotometric determination of atropine, in
bulk sample and in dosage form. The methods are accurate, simple, rapid, inexpensive and
sensitive. The first method depending on the extraction of the formed ion-pair complex with
bromphenol blue (BPB) as a chromogenic reagent in chloroform, use phthalate buffer of pH
3.0; which showed absorbance maxima at 413 nm against reagent blank. The calibration
graph is linear in the ranges of 0.5-40 µg.mL
-1
with detection limit of 0.363µg.mL
-1
. The
second method depending on the measure of the absorbance maxima of the formed charge-transfer complex with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) at 457 nm against

This research involves an indirect Fluorophotometric method for the determination of microgram amount of oxymetazoline hydrochloride in the concentration range 0.1-5.0 g/ml. The method is based on the oxidation of the drug by cerium sulphate solution which is acidic medium where Ce IV is reduced to Ce III which can be excited at 259 nm to give an emitted light at 377 nm which  is directly proportional to the concentration of Ce III which is equivalent to Ce IV that is needed to oxidize the studied drug. The average recovery of the method is 100.19% and relative standard deviation (RSD) < 0.37% . The method have been successfully applied to the determination of the studied drug in its pure and pharmaceutical preparations and it wa

Simple and sensitive batch and Flow-injection spectrophotometric methods for the determination of Procaine HCl in pure form and in injections were proposed. These methods were based on a diazotization reaction of procaine HCl with sodium nitrite and hydrochloric acid to form diazonium salt, which is coupled with chromatropic acid in alkaline medium to form an intense pink water-soluble dye that is stable and has a maximum absorption at 508 nm. A graphs of absorbance versus concentration show that Beer’s law is obeyed over the concentration range of 1-40 and 5-400 µg.ml-1 of Procaine HCl, with detection limits of 0.874 and 3.75 µg.ml-1 of Procaine HCl for batch and FIA methods respectively. The FIA average sample throughput was 70 h-1. A

     Tow simple, rapid and sensitive spectrophotometric methods for the determination of mesalazine in pharmaceutical preparations have been carried out. The proposed methods depend on oxidative coupling reaction of mesalazine with m-aminophenol in the existence of N-bromosuccinamide in alkaline medium (method A) and 2,6-dihydroxybenzoic acid in the existence of sodium metaperiodate in basic medium (method B) to produce colored products , show highest absorptions at 640 (nm) and 515 (nm), alternately. Beer’s law was consistent in concentrations extent of 1.25-30 and 0.5-12.5 (µg.mL^-1) with molar absorptivity of 0.36×10⁴ and 0.77×10⁴ L.mol^-1.cm<

New, simple and accurate batch and flow injection spectrophotometric
methods have been developed for the determinationsof tetracycline
hydrochloride (TCH) and doxycycline hyclate (DCH) in pharmaceutical
preparations. The methods are based on diazotization of
metchlopramide and coupling reaction with either TCH or DCH in alkaline
medium to form yellow–orange water soluble dye with absorption maxima
at 414 and 436 nm for TCH and DCH, respectively. A graphs of absorbance
versus concentration show that Beer’s law was obeyed over the
concentration ranges of 1 –52 μgmL-1 TCH and DCH for batch method and
of 8 – 240 μg mL-1 TCH and 5 – 350 μgmL-1 DCH for FIA method. The
limits of detection in batchmetho