Charge transfer complex formation method has been applied for the spectrophotometric determination of cimetidine, in bulk sample and dosage form. The method was accurate, simple, rapid, inexpensive and sensitive depending on the formed charge- transfer complex between cited drug and, 2,3-Dichloro-5,6-dicyano-p- benzoquinone (DDQ) as a chromogenic reagent. The formed complex shows absorbance maxima at 587 nm against reagent blank. The calibration graph is linear in the ranges of (5.0 - 50.0) µg.mL-1 with detection limit of 0.268µg.mL-1. The results show the absence of interferences from the excipients on the determination of the drug. Therefore the proposed method has been successfully applied for the determination of cimetid

Charge transfer complex formation method has been applied for the spectrophotometric determination of erythromycin ethylsuccinate, in bulk sample and dosage form. The method was accurate, simple, rapid, inexpensive and sensitive depending on the formed charge- transfer complex between cited drug and, 2,3- Dichloro-5,6-dicyano-p- benzoquinone (DDQ) as a chromogenic reagent. The formed complex shows absorbance maxima at 587 nm against reagent blank. The calibration graph is linear in the ranges of (10 - 110) μg.mL-1 with detection limit of 0.351μg.mL-1. The results show the absence of interferences from the excipients on the determination of the drug. Therefore the proposed method has been successfully applied for the determination of eryth

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 simple, accurate and precise spectrophotometric method has been developed for the analysis of sulfamethoxazole (SMZ) in pure form and pharmaceutical preparation. The method involves a direct charge transfer complexation of sulfamethoxazole (SMZ) with sodium nitroprusside (SNP) in alkaline medium and the presence of hydroxyl amine hydrochloride. Variables affecting the formation of the formed orange colored complex were optimized following two approaches univariate and central composite experimental design (CCD) multivariate. Under optimum recommended conditions, the formed complex exhibits λmax at 512 nm and the method conforms Beer's law for SMZ concentration in the range of 5.0-150.0 (µg.mL-1) with molar absorptivi

A simple, rapid, accurate and sensitive spectrophotometric method is  proposed  for  the  detennination  of chlorprQm<tZine -HCl  in  pwe form  and  in pharmaceutical  formulation. This method is based on the formation.  of ion  assodation complexes  of  dmg   with either  thymol

blue or  bromophenol  blue  in an acidic buffer at pH  values 4.17  and

3.68, respectively.

The ion-pair  complexes  formed exhibit absorption maxima  at 41 Onm for  both  thymol   blue and  bromophenol  blue.  These  complexes· are quantitatively extracted  &n

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

Cefixime (CFX) was treated with sodium nitrite and hydrochloric acid for diazotization reaction followed by coupling with ?-Naphthol in alkaline medium to form, a yellow colored azo dye compound which exhibits maximum absorption (?_max) at 412 nm where the concentration of (CFX) was determined spectrophotometrically. The optimum reaction conditions and other analytical parameters were evaluated. Beer’s law was obeyed in the concentration range of (1-20) ?g.mL^-1 with a molar absorptivity of 34870.5 L.mol^-1.cm^-1. The limit of detection was found to be 0.1090 ?g.mL^-1 and the Sandell's sensitivity value was 0.0130 ?g.cm^-2. The proposed method could be successfully applied to

charge transfer complex formed by interaction between the p- aminodiphenylamine (PADPA) as electron donor with iodine as electron acceptor in ethanol at 250C as evidenced by color change and absorption. The spectrum obtained from complex PADPA – Iodine shows absorptions bands at 586 nm. All the variables which affected on the stability of complex were studies such as temperature, pH, time and concentration of acceptor. The linearity of the method was observed within a concentration rang (10–165) mg.L-1 and with a correlation coefficient (0.9996), while the molar absorbitivity and sandell sensitivity were (4643.32) L.mol-1.cm-1 and (0.0943) μg.cm-2, respectively. The adsorption of complex PADPA–I2 was studied using adsorbent surfaces

     Two rapid, simpleand sensitive flow injection methods were developed for the estimation of metronidazole (MRZ) in pharmaceutical formulations. The proposed methods were based on charge transfer reaction between metol (N-methyl-p-aminophenol sulfate) as a Ï€-acceptorand reduced MRZ as an n-donor to produce a blue colored chargetransfer complex. Method A depends on the reaction of reduced MRZ with metol (MT) in the presence of NaIO₄ using two lines manifold to form blue colored product exhibiting absorption maxima at 700 nm.While method B depends on charge transfer reaction of reduced MRZ with MT in presence of a solid phase reactorcontainingfixedFePO₄ on cellulose acetateusing reverse flow