A simple, fast, and sensitive batch and flow injection spectrophotometric
methods have been developed for the determination of clonazepam(CZP) in pure
form and in pharmaceutical preparations. The proposed methods are based on the
oxidative coupling reaction of the reduced clonazepam using Zn powders and conc.
HCl with payrocatechol and in the presence of ferric sulphate. The resulting reddish
colored product had a maximum absorbance at 515 nm. The optimum reaction
conditions and other analytical parameters have been evaluated . The linear ranges
for the batch and FI methods determination of CZP were 0.5-32, 50-400 μg mL-1
and the detection limits were 0.193, 22.60 μg mL-1 for both methods respectively.
Statis

Mefenamic acid belongs to non-steroidal anti-inflammatory drugs that are used widely for the treatment of analgesia. Our aim from this study is to establish a new assay for the quantitative determination of mefenamic acid (MFA) in the pharmaceutical sample by two sensitive and rapid flow injection-fluorometric methods. A homemade fluorometer was used in fluorescence measurements, which using solid-state laser diode 405 and 532 nm as a source, combined with a continuous flow injection technique. The first method depends on the effect of MFA on calcein blue (CLB) fluorescence at 405 nm. Another method is a study of rhodamine-6G (Rh-6G) fluorescence after adding MFA, and recording at 532 nm. Optimum parameters as fluorescent dye concen

Spectrophotometric  methods  were  developed   for    the determination of rantidine-HCl in pharmaceutical tablets. These methods were based on the reaction of DDQ and p-chloranil with rantidine-HCl, resulting in the formation of an orange-red and purple colored products which are quantified spectrophotometrically at 460 and 540nm in DDQ and p-chloranil, respectively. A graph of absorbance versus concentration show that Beer’s law is obeyed in a concentration ranges of 20-160 and (30-120)g/ml with molar absorptivities of 2.631 x 103 and 1.052 x 103l .mol-1-cm-1 for DDQ and  p-chloranil, respectively. The optimum conditions for  color development  are described and 

Determining the actual amounts of active ingredients in various pharmaceutical commercial forms is still receiving a lot of attention. Two flow injection analysis (FIA) methods were suggested for determination of mesalazine (MES) in pharmaceutical forms. Normal and reverse FIA systems (nFIA and rFIA) combined with UV-Vis spectrophotometric technique were used for the analysis. The methods involved using two mods of FIA systems for measuring a colored product result from coupling of MES with 2,2'-dihydroxybiphenyl after oxidized with sodium periodate in alkaline medium. The absorbance of the red colored dye was measured at maximum wavelength of 500 nm. The calibration graphs for MES were linear in the ranges 2.5-200 and 0.5-60 µg/mL with

Strong acids were determined via the precipitation reaction of loaded copper (II) ion on strong cation exchange resin which in turn reacts with potassium hyxacyano ferrate (II). The attenuation effect of formed precipitate Cu2 [Fe (CN) 6] on (0 -180o) incident LED light was measurement via homemade AYAH 5SX4-ST-5D solar CFI analyser. Optimum parameters were 0.005M.L-1 [Fe(CN)6]-4 , flow rate of 2.4 mL.min-1 , sample volume 204 μL , sample purge time of 64 seconds was chosen, and 1.6 V for light intensity. A liner calibration graph of 0.005 -0.2 M.L-1 were obtains for HCl, HNO3, HCLO4 and H2SO4, with a linearity (r2 %) 96 -97 % and L.O.D based on gradual dilution of lowest concentration in calibration graph was 37.19 μg for HCl, 64.273

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

 Two simple and sensitive spectrophotometric methods are proposed for the determination of amitriptyline in its pure form and in tablets. The first method is based on the formation of charge- transfer complex between amitriptyline as n-donor and tetracyano-ethylene (TCNE) as Ï€acceptor. The product exhibit absorbance maximum at 470 nm in acetonitrile solvent (pH =9.0 ) . In the second method the absorbance of the ion- pair complex, which is formed between the soughted drug and bromocresol green (BCG), was measured at 415 nm at ( pH=3.5) . In addition to classical univariate optimization, modified simplex method (MSM) was applied in the optimization of the variable affecting  the color producing reaction by a geometric simple

This approach was developed to achieve an accurate, fast, economic and sensitivity to estimation of diphenhydramine Hydrochloride. The dye that produced via reaction between diphenhydramine HCl with thymol blue in acidic medium pH ≈ 4.0. The ion pair method include an optimization study to formed yellowcolored that extraction by liquid – liquid method. The product separated of complexes by using by chloroform solution measured spectrophotometry at 400 nm. The analysis data at optimum conditions showed that linearity concentration in a range of calibration curve 1.0 – 50 μg /mL, limit of detectionand limit of quantification 0.0786 and 0.2358 μg/mL respectively. The molar absorptivity and Sandell’s sensitivity were 1.8 × 10 -4 L/mo