Colorimetric Determination of Certain Phenothiazine Drugs by Using Morpholine and Iodine-Potassium Iodide Reagents

1986 ◽  
Vol 69 (3) ◽  
pp. 513-518 ◽  
Author(s):  
Adel F Youssef ◽  
Salwa R El-Shabouri ◽  
Fardous A Mohamed ◽  
Abdel Maboud I Rageh
Keyword(s):  
Potassium Iodide ◽  
Quantitative Estimation ◽  
Colorimetric Method ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Colorimetric Determination ◽  
Reaction Products ◽  
Phenothiazine Drugs ◽  
Lower Molar

Abstract A colorimetric method was developed for the quantitative estimation of 11 phenothiazine drugs. The method is based on the interaction of unsulfoxidized drug with morpholine and iodine-potassium iodide reagents. The interaction for all studied phenothiazine drugs yields a blue product with 2 absorption maxima: one in the range of 620-640 nm with lower molar absorptivity and the other in the range of 662-690 nm with higher molar absorptivity. The color was stable for at least 10 h. The reproducibility and recovery of the method were excellent. The method was applied successfully to the analysis of various commercially available phenothiazines in different dosage forms. The results were comparable to those obtained by official procedures. The suitability of the method for detection and estimation of promethazine excreted in urine has been suggested by preliminary experiments. Reaction products have been isolated and identified.

Colorimetric Determination of Terbutaline Sulfate and Orciprenaline Sulfate via Nitrosation and Difference Spectrophotometry

1987 ◽  
Vol 70 (3) ◽  
pp. 568-571 ◽  
Author(s):  
Mohamed E El-Sadek ◽  
Hisham E Abdel Latef ◽  
Afaf A Aboul Khier
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Nitrite ◽  
Colorimetric Method ◽  
Dosage Forms ◽  
Alkaline Media ◽  
Colorimetric Determination ◽  
Pharmaceutical Dosage Forms ◽  
Terbutaline Sulfate ◽  
The Difference

Abstract A colorimetric method is proposed for determination of terbutaline sulfate, orciprenaline sulfate, and their dosage forms. The suggested method depends on nitrosation of the 2 drugs by using sodium nitrite and hydrochloric acid. Addition of sodium hydroxide increases the intensity of the color developed. The difference between absorption values measured in acid and alkaline media is taken as a measure of concentration. Variables were carefully studied and optimized. Results for both compounds adhered to Beer's law over the range 2- 28 μg/mL. The method has proved to be accurate and precise for analysis of pharmaceutical dosage forms.

scholarly journals A novel sensitive colorimetric determination of catecholamine drug in dosage form via oxidative coupling reaction with MBTH and potassium ferricyanide

2021 ◽  
Vol 5 (1) ◽  
pp. 51-58
Author(s):  
Safwan Ashour
Keyword(s):  
Oxidative Coupling ◽  
Colorimetric Method ◽  
Standard Free Energy ◽  
Coupling Reaction ◽  
Pharmaceutical Formulations ◽  
Molar Absorptivity ◽  
Potassium Ferricyanide ◽  
Colorimetric Determination ◽  
Oxidative Coupling Reaction

A new and direct colorimetric method has been established for the determination of catecholamine (methyldopa, MD) in both pure form and in pharmaceutical formulations. The method is based on the oxidative coupling reaction of MD with 3-methyl-2-benzothiazolinone hydrazone hydrochloride monohydrate (MBTH) and potassium ferricyanide at pH 10.4 in aqueous medium to form an orange product that has a maximum absorption at 460 nm. Beer's law plot showed good correlation in the concentration range of 1.0−56.0 µg mL-1, with detection limit of 0.31 µg mL-1. Molar absorptivity for the above method was found to be 6.56×103 L mol-1 cm-1. All the measurements were carried out at 25 ± 1.0 °C, the formation constant (logKf) value of colored species is 9.48 and the standard free energy (DG‡) is − 54.09 KJ mol-1. This method was applied successfully to determination of MD in tablets and the results were compared with the USP method. Common excipients used as additives in tablets do not interfere in the proposed method. The method is accurate, precise and highly reproducible, while being simple, cheap and less time consuming and hence can be suitably applied for routine analysis of MD in bulk and dosage forms.

Colorimetric Determination of Acetylenic Hypnotics by Formation of Silver Acetylides

1980 ◽  
Vol 63 (1) ◽  
pp. 88-90
Author(s):  
Mohamed S Rizk ◽  
Mohamed I Walash ◽  
Amina El-Brashy
Keyword(s):  
Methyl Ketone ◽  
Good Accuracy ◽  
Colorimetric Method ◽  
Silver Ions ◽  
Dosage Forms ◽  
Colorimetric Determination ◽  
Pharmaceutical Dosage Forms ◽  
Hypnotic Drugs ◽  
Silver Acetylide

Abstract A colorimetric method is described for the determination of certain mono-substituted acetylenic hypnotic drugs—ethinamate, methyl pentynol carbamate, and ethchlorvynol. Silver acetylide is formed and extracted into isobutyl methyl ketone. After acidification, an equivalent amount of silver ions is liberated which is assayed colorimetrically as silver dithizonate (λ max. 472 nm). About 10–50 μg compound could be assayed with good accuracy. The procedure is reproducible and precise (standard deviation 1.5–2.19%). The procedure was successfully applied to different pharmaceutical dosage forms.

Colorimetric Determination of Tetracycline Hydrochloride in Pharmaceutical Preparations

1987 ◽  
Vol 70 (4) ◽  
pp. 686-688 ◽  
Author(s):  
Utpal Saha
Keyword(s):  
Copper Complexes ◽  
Colorimetric Method ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Tetracycline Hydrochloride ◽  
Colorimetric Determination ◽  
Reagent Blank ◽  
Yellowish Green ◽  
Green Solution

Abstract A simple, sensitive, and rapid colorimetric method is presented for the estimation of tetracycline hydrochloride as the pure drug and in formulations. The proposed method is based on the reaction of tetracycline HC1 with cupric chloride in an alkaline medium to give a yellowish green solution whose absorbance is measured at 400 nm against a reagent blank. The color obeys Beer's law in the concentration range of 0-20 μg/mL. Molar absorptivity and Sandell's sensitivity of the yellowish-green copper complexes of tetracycline HC1 are 1.99 x 104 Lmol-1 cm-1 and 0.0241 ppm, respectively.

scholarly journals VALIDATED SPECTROPHOTOMETRIC METHOD TO DETERMINE VARDENAFIL AND SILDENAFIL IN PHARMACEUTICAL FORMS USING POTASSIUM IODIDE AND POTASSIUM IODATE

2017 ◽  
Vol 9 (10) ◽  
pp. 65 ◽  
Author(s):  
Amir Alhaj Sakur ◽  
Shaza Affas
Keyword(s):  
Potassium Iodide ◽  
Spectrophotometric Method ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Potassium Iodate ◽  
Average Recovery ◽  
Beer's Law ◽  
Beer’S Law ◽  
Good Agreement

Objective: To develop and validate simple, sensitive, precise and free of organic solvents method for the determination of sildenafil (SIL) and vardenafil (VAR) in bulk and pharmaceutical formulation.Methods: The method is based on the reaction of studied drugs with a mixture of potassium iodide and potassium iodate in an aqueous medium at (25±2 °C) to form yellow coloured triiodide ions (I3-) within 45 min. The reaction is followed spectrophotometrically by measuring the absorbance at 288, 351 nm and 285, 351 nm for sildenafil and vardenafil respectively.Results: The effects of analytical parameters on the reported systems were investigated. Beer's law of SIL was obeyed in the range of (0.4-12) μg ml-1and (0.6-16) μg ml-1. Molar absorptivity was found to be (67.659 ×103) lmol/cmand (37.955×103) lmol/cm at 288 nm, 351 nm respectively. Beer's law of VAR was obeyed in the range of (0.2-13) μg/mland (0.5-40) μg/ml. Moreover, molar absorptivity’s were found to be (68.719 ×103) l mol-1 cm-1and (26.691×103) l mol-1 cm-1 at 285 nm, 351 nm respectively.Conclusion: The proposed method has been applied to determine the components in dosage forms with an average recovery of 98.15% to 103.45% and the results have been found in good agreement with those results obtained by the reference methods.

Colorimetric Determination of Fluoride in Drinking Groundwater using a Polymeric Zirconium Complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline

2013 ◽  
Vol 12 (7) ◽  
pp. 460-465
Author(s):  
Sameer Amereih ◽  
Zaher Barghouthi ◽  
Lamees Majjiad
Keyword(s):  
Drinking Water ◽  
Detection Limit ◽  
Complex Formation ◽  
Molar Absorptivity ◽  
Colorimetric Determination ◽  
Zirconium Complex ◽  
Reliable Determination ◽  
Percentage Recovery ◽  
Quantitation Limit

A sensitive colorimetric determination of fluoride in drinking water has been developed using a polymeric zirconium complex of 5-(2-Carboxyphenylazo)-8-Hydroxyquinoline as fluoride reagents. The method allowed a reliable determination of fluoride in range of (0.0-1.5) mg L-1. The molar absorptivity of the complex formation is 7695 ± 27 L mol-1 cm-1 at 460 nm. The sensitivity, detection limit, quantitation limit, and percentage recovery for 1.0 mg L-1 fluoride for the proposed method were found to be 0.353 ± 0.013 μg mL-1, 0.1 mg L-1, 0.3 mg L-1, and 101.7 ± 4.1, respectively.

Spectrophotometeric Determination of Trifluoperazine HCL in Pure Forms and Pharmaceutical Preperations

2017 ◽  
Vol 9 (5) ◽  
Author(s):  
Mohammad Hamzah Hamzah ◽  
Rawa M M Taqi ◽  
Muna M. Hasan ◽  
Raid J. M. Al-Timimi
Keyword(s):  
Standard Method ◽  
Limit Of Detection ◽  
Molar Absorptivity ◽  
Dosage Forms ◽  
Oxidizing Agent ◽  
Optimum Conditions ◽  
Limit Of Quantification ◽  
Cerium Ion ◽  
Blank Solution

A simple and accurate spectrophotometric method for the determination of Trifluoperazine HCl in pure and dosage forms was developed. The method is based on the reaction between Trifluoperazine HCl and p-chloroaniline in the presence of cerium ion as oxidizing agent which lead to the formation of violate color product that absorbed at a maximum wavelength 570nm while the blank solution was pink. Under the optimum conditions a linear relationship between the intensity and concentration of TRF in the range 4-50μg/ml was obtained . The molar absorptivity 3.74×103 L.mol-1.cm-1 , Limit of detection (2.21μg/ml), while limit of quantification was 7.39μg/ml. The proposed analytical method was compared with standard method using t-test and F-test , the obtained results shows there is no significant differences between proposed method and standard method. Based on that the proposed method can be used as an alternative method for the determination of TRF in pure and dosage forms.

Colorimetric Determination of Hydroxyproline as Measure of Collagen Content in Meat and Meat Products: NMKL Collaborative Study

1990 ◽  
Vol 73 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Kurt Kolar
Keyword(s):  
Collaborative Study ◽  
Colorimetric Method ◽  
Meat Products ◽  
Acid Oxidation ◽  
Colorimetric Determination ◽  
Mean Values ◽  
Collaborative Studies ◽  
Freeze Dried ◽  
Analytical Result

Abstract A colorimetric method for the determination of hydroxyproline as a measure of collagen in meat and meat products has been collaboratively studied in 18 laboratories. The method includes hydrolysis with sulfuric acid, oxidation with chloramine- T, and formation of a reddish purple complex with 4- dimethylaminobenzaldehyde. Five frozen and 3 freeze-dried samples were tested, ranging in content from 0.11 to 0.88% and from 0.39 to 4.0% hydroxyproline, respectively. The mean values of 2 identical samples were 0.245 and 0.251 %. The average recovery from a spiked sample was 96.1 %. The hydroxyproline content of a known sample (a mixture of 2 samples in the ratio 5:2) was calculated to 1.42%, which agrees well with the analytical result, 1.40%. In comparison with other collaborative studies, based on the ISO analytical method, the repeatability and reproducibility of this method agree well with the other results. This method was accepted as an official NMKL method by all national Committees, and has been adopted official first action by AOAC as an NMKLAOAC method.

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