Flow injection-spectrophotometeric determination of some catecholamine drugs in pharmaceutical preparations via oxidative coupling reaction with p-toluidine and sodium periodate

2005 ◽  
Vol 538 (1-2) ◽  
pp. 331-335 ◽  
Author(s):  
Loay K. Abdulrahman ◽  
Anas M. Al-Abachi ◽  
Mayada H. Al-Qaissy
2020 ◽  
Vol 10 (03) ◽  
pp. 323-327
Author(s):  
Ahmed Hamdi Hattab ◽  
Abdul Majeed Khorsheed Ahmed ◽  
Sunbul M. Anwar

Phenylephrine is a medication mainly applied as a decongestant to relieve hemorrhoids, increase blood pressure, and dilate the pupil. It is the first-line choice for prevention and treatment of hypotension during spinal anesthesia for cesarean section. However, many methods were used for the determination of this drug and its properties. This paper proposes a method that uses N, N dimethyl-p-phenylenediamine dihydrochloride as a new chromogenic reagent (NNDPH). This method is based on the oxidative coupling reaction of phenylephrine with N, N dimethyl-p-phenylenediamine dihydrochloride with ferric chloride in basic media to form green-blue soluble dye product. The outcomes demonstrate that the maximum absorption is at 680 nm, molar absorptivity of 5.54 × 103 mol-1.cm-1, and Sandell’s sensitivity of 0.038 μg.cm-2. The concentration range of 4 to 22 μg.mL-1 of the product is conformable to Beer’s law. Furthermore, it is applied successfully for estimating the drug properties on a simple condition or pharmaceutical preparations.


2016 ◽  
Vol 13 (2) ◽  
pp. 489-495
Author(s):  
Baghdad Science Journal

New, simple and sensitive batch and reverse FIA spectrophotometric methods for the determination of doxycycline hyclate in pure form and in pharmaceutical preparations were proposed. These methods based on oxidative coupling reaction between doxycycline hyclate and 3-methylbenzothiazolinone-2-hydrazone hydrochloride (MBTH) in the presence ammonium ceric sulfate in acidic medium, to form green water-soluble dye that is stable and has a maximum absorbance at 626 nm. A calibration graph shows that a Beer's law is obeyed over the concentration range of 1-80 and 0.5-110 ?g.mL-1 of DCH for the batch and rFIA respectively with detection limit of 0.325 ?g.mL-1 of DCH for r-FIA methods. All different chemicals and physical experimental parameters affecting the development and stability of the colored product were carefully studied. The proposed methods were successfully applied for the determination of DCH in pharmaceutical preparations.


2021 ◽  
Vol 13 (1) ◽  
pp. 65-76
Author(s):  
Noor M. Ghaib Allah1 ◽  

A new, simple, rapid and sensitive spectrophotometric method for the determination of sulfamethoxazole in both pure form and pharmaceutical preparations has been reported.The adapted technique based on utilization 4-aminobenzene sulfonic acid as a new modern chromogenic through an oxidative coupling reaction with sulfamethoxazole and potassium iodate in basic media to form orange soluble dye product with absorption maxima at 490 nm. Subject to Beer's law in the range 2–32μg mL-1. The values of molarabsorption coefficient (ε) and correlation coefficient were found to be 9.118 × 103 and0.9999 respectively whereas the Sandels index was 0. 02778 µg.cm-2


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