A rapid, sensitive and selective spectrophotometric method was developed for determination of sulfathiazole (STHZ) in aqueous solution. The method is based on the  oxidative coupling reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH) in a basic medium (pH 10.9) in the presence of  potassium periodate to produce an intense orange colour, soluble in water , stable product and absorbs at 492 nm. Beer's law was in the linear range 2.0-28.0 μg/ml of sulfathiazole, the molar absorptivity, Sandellʼs sensitivity index and detection limit were 1.1437 ×104 liter. mol-1.cm-1,0.0223 μg.cm-2 and 0.1274 μg/ml respectively. The RSD value was  0.75 - 1.12 % depending on the concentration. This method was applied successfu

A simple and sensitive spectrophotometric method is described for the determination of diclofenac sodium (DCL), in pure form and pharmaceutical formulations. The method is based on the oxidation of 2,4-dinitrophenylhydrazine (2,4-DNPH) and coupling of the oxidized product with DCL in alkaline medium to give intensively colored chromogen which exhibits maximum absorption (λmax) at 600 nm, and the concentration of DCL was determined spectrophotometrically. The optimum reaction conditions and other analytical parameters were evaluated. In addition to classical univariate optimization, modified simplex method (MSM) has been applied in optimization of the variables affecting the color producing reaction. Beer’s law is obeyed in the

A simple, accurate and sensitive spectrophotometric method for the determination of Procaine penicillin (PP) is described. The method is based on charge-transfer reaction of PP with metol (N-methyl-p-hydroxy aniline) in the presence of ferric sulphate to form a purple-water soluble complex ,which is stable and has a maximum absorption at 510 nm .A graph of absorbance versus concentration shows that Beer’s low is obeyed over the concentration range of 3-80 µg /ml of PP (i.e.,3-80 ppm) with a molar absorbativity of 4.945 ×103 L.mol-1.cm-1 ,Sandell sensitivity of 0.1190 µg cm-2 ,a relative error of (-1.57)-2.79 % and a standard deviation of less than 0.59 depending on the concentration of PP.The optimum conditions for full co

A simple, accurate and sensitive spectrophotometric way is used to determine Bisacodyl in pure and pharmaceutical preparations. The proposed method depends on using 2,4-Dinitrophenylhydrazine as chromogenic reagent . The method was based on the oxidative coupling reaction of Bisacodyl with 2,4-Dinitrophenylhydrazine with Sodium periodate in the presence of sodium hydroxide as alkaline media to form red water soluble dye product , that has a maximum absorption at ?max 522nm . Beer ,s law is obeyed in the concentration of (2.00–20.00) ?g.ml -1 .The molar absorptivity is (6505) L.mol-1.cm-1,a sandall sensitivity of(0.0555) ?g.cm-2), correlation coefficient of (0.9970) , Limitof detection (LOD) (0.0312 ?g.ml-1), limit of Quantitation (LOQ) (

    Simple, sensitive, accurate and inexpensive spectrophotometric methods have been developed for the determination of sulfamethoxazole (SMZ) in pure and dosage forms. This method is based on diazotization of primary amine group of sulfamethoxazole with sodium nitrite and hydrochloric acid followed by coupling with diphenylamine in acidic medium to obtain a stable blue colored dye and show a maximum absorption (max) at 530 nm. Different variables affecting the completion of reaction have been carefully optimized, following the classical univariate sequence and modified simplex method. Beer’s law is obeyed in the concentration range of (0.5-12.0 µg.mL-1) with molar absorptivity of 4.9617×104 L.mol-1.cm-1. The

A new, Simple, sensitive and accurate spectrophotometric methods have been developed for the determination of sulfanilamide (SNA) drug in pure and in synthetic sample. This method based on the reaction of sulfanilamide (SNA) with 1,2-napthoquinone-4-sulphonic acid (NQS) to form N-alkylamono naphthoquinone by replacement of the sulphonate  group of the naphthoquinone sulphonic acid by an amino group. The colored chromogen shows absorption maximum at 455 nm. The optimum conditions of condensation reaction forms were investigated by: (1) univariable method, by optimizing the effect of experimental variables; (different bases, reagent concentration, borax concentration and reaction time),     (2) central  composite design (CCD) including

A simple, sensitive, accurate, and precise spectrophotometric method for the determination of clonazepam (CLNZ) was developed. The method is based on charge transfer reaction between CLNZ and p-Bromanil (p-Br) to form a colored complex. The optimum conditions of complex formation were investigated by (1). Unvariable method, for the optimization of reagent concentration, base concentration, temperature, and time. (2). Multivariable simplex method including the effect of three experimental factors via; reagent concentration, concentration of NaOH and time. The linearity range of CLNZ was (1-30) μg.mL^-1 at 378 nm under condition established via simplex method with molar absorptivity (1.9069x10⁴) L.

A new, simple and sensitive spectrophotometric method was described for the determination of famotidine (FAM) as a pure material and in pharmaceutical formulation. This method was based on diazotization and coupling reaction between famotidine and diazotized solution of metochlopramide hydrochloride (DMPH) in the presence of phosphate buffer solution to give a compound of azo dye having orange color soluble in water with high absorptivity at a wave length of 478 nm. The data shows that FAM and DMPH combine in the molar ratio of 1:1 at PH 7.0 .The method obeys Beer's law over concentration range of 1-40 ?g.ml-1 of famotidine with a correlation coefficient of 0.9955 and a detection limit of 0.10 ?g.ml-1. The apparent molar absorptivity re

A simple, rapid spectrophotometric method has been established for the determination of chlorpromazine hydrochloride (CPZ) in its pure form and in a tablet formulations. The  suggested  method  is  based  on  the  oxidative coupling  reaction  with4-nitroainlline using KIO₃ in acidic solution to produce a violet colored product with maximum absorption at λ=526 nm.The  analytical data  obtained  throughout  this  study  could  be  summarid  as  follows:  1ml of 1M HCl (pH=2.2), 1 ml  of  4-nitroanilline (1x10^-2M), and 1.5ml  of (1x10^-2)KIO₃ per 25 ml reaction medium. The order of a

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