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

Author(s):  
Amir Alhaj Sakur ◽  
Shaza Affas

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.

Author(s):  
Ratnamala P. Sonawane ◽  
R.S. Lokhande ◽  
Utkarsha M. Chavan

A spectrophotometric method has been developed for the determination of Fe(III) using 2-Hydroxy-1-Naphthalene carboxaldehyde phenyl hydrazone as an extractive reagent. The reagent forms a coloured complex, which has been quantitatively extracted into ethyl acetate at pH 6. The method obeys Beer’s law over arrange from 1 to 7 ppm. The Molar absorptivity and Sandell’s sensitivity were 0.31 × 104 L mol-1cm-1 and 0.13 μg cm-2 respectively. The proposed method is very sensitive and selective. The method has been successfully applied to synthetic and commercial samples.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ramesh Kataria ◽  
Harish Kumar Sharma

An extractive spectrophotometric method for the determination of the trace amounts of tin has been carried out by employing 6-chloro-3-hydroxy-2-(2′-thienyl)-4-oxo-4H-1-benzopyran (in acetone) (CHTB) for the complexation of the metal ion in HCl medium. The colored species thus produced is quantitatively extracted into dichloromethane and shows the maximum absorbance at 432–437 nm. The method obeys Beer’s law in the range 0.0–1.3 μg mL−1 of tin with molar absorptivity and Sandell’s sensitivity of 5.81×104 L mol−1 cm−1 and 0.0020 μg Sn cm−2, respectively, at 435 nm. The method is highly selective and free from the interference of a large number of elements including platinum metals. The ratio of metal to ligand in the extracted species is 1 : 2. Utilizing this method, the analysis of various synthetic and technical samples including gun metal and tin can have been carried out satisfactorily.


2000 ◽  
Vol 68 (3) ◽  
pp. 263-273 ◽  
Author(s):  
Hisham E. Abdellatef ◽  
Abdalla A. Shalaby ◽  
Heba M. Elsaid ◽  
Magda M. Ayad

Two colorimetric and titrimetric procedures are developed for determination of some cephalosporins, namely, cefotaxime sodium (CFT), cehroxime sodium (CFU) and ceftazidime pentahydrate (CFZ). The first method, a colorimetric method, was based on the reaction of these cited drugs with 4-chloro-7-nitrobenzofurazan (NBD-Cl), in the presence of 5x10-3 M borax, with the formation of stable colored chromogens with maximum absorbance in the range of 409 - 414 nm. All variables affecting the development of the colour have been investigated and the conditions were optimized. The method obeys Beer's law over concentration ranges of 19.09 - 95.49, 17.85 - 124.98 and 63.66 - 254.66 µg ml-1 of CFT, CFU and CFZ, respectively. Obedience to Beer's law permitted the successful application of the proposed method for the assay of cefuran, cefumax and fortum vials. The results obtained reveal good percentage recoveries, which are in good agreement with those obtained by the official methods. In the second method, the titrimetric method, the conditions for the oxidimetric titration of cephalosporins have been studied. The titration takes place because of catalytic quantities of KBr, which give rise to an intermediate that can be hydrolyzed to the sulfoxide. The operating conditions are described and a hypothesis is put forward concerning the mechanism of the reaction.


1989 ◽  
Vol 72 (6) ◽  
pp. 885-889 ◽  
Author(s):  
Abdel-Maboud I Mohamed

Abstract A new spectrophotometric method for the determination of some unsubstituted benzene sulfonamides is presented. The method is based on the interaction of these derivatives with 7,7,8,8-tetracyanoquinodimethane at pH 9.0-9.5 to produce intense blue products. The quantitation of the products was carried out at 578 nm. Beer’s law was obeyed over a wide range of concentrations for all sulfonamide compounds studied. Optimum analytical conditions were determined, and the color produced was stable for at least 90 min at 25 °C. Analytical data for determination of sulfonamide compounds in pure form are presented together with application of the proposed method for analysis of some commercially available pharmaceutical preparations. The results are in good agreement with those obtained by official procedures.


2020 ◽  
Vol 33 (1) ◽  
pp. 65-72
Author(s):  
Jyoti Goswami ◽  
Thakur Vikram Singh ◽  
Chhaya Bhatt ◽  
Deepak Kumar Sahu ◽  
Kalpana Wani ◽  
...  

Pesticides are designated mixture of substances for extenuating and destroying any group of pests such as insects and vegetation. Pymetrozine [6-methyl-4-[(E)-pyridin-3-ylmethylideneamino]-2, 5-dihydro-1, 2, 4-triazin-3-one] is a pyridine azomethine compound which represents a class of insecticide. A Spectrophotometric method has been developed on the modified Fujiwara reaction for the determination of pymetrozine. Pymetrozine directly reacts with chloroform the 45-500C turns out the violet color in the formation of Schiff’s Base (Glutaconic Aldehyde). In the present reaction, the violet color obtained is discharged with a few drops of acetic acid followed by the addition of p- nitro aniline reagent which gives yellow color dyes. The absorption maxima of yellow-colored dye measured at 430 nm. Beer’s law is obeyed over the range of 1 to 10 µg per 10 ml of pymetrozine. The molar absorptivity of the colored system is 1.38×105 L mol-1 and Sandall’s sensitivity is 1.0×10-3µg cm-2. This method is free from the interference of other interfering and can be successfully applied for the determination of various ecological samples.


Author(s):  
G. Sreenivasula Reddy ◽  
P. Raveendra Reddy

A highly sensitive spectrophotometric method has been developed for the determination of copper (II) using 3-methylthiophene-2-carbaxaldehyde-3-thilosemicarbazone (3-MTAT) as an analytical reagent. The 3-MTAT forms reddish brown species of copper (II) at a pH range of 5.0-7.0. The Cu (II)-3-MTAT complex shows maximum absorbance at 430 nm, with molar absorptivity and Sandell’s sensitivity being 1.6 x 104 L Mol-1 Cm-1 and 3.6 x 10-3 μg cm-2 respectively. The system obeys Beer’s law in the range of 0.35-3.53mg/L. The regression coefficient of the Beer’s law straight line is 0.338, and the correlation coefficient is 0.999. The detection limit of the method is 0.021 μg mL-1. Most of the common metal ions generally found associated with copper do not interfere. The repeatability of the method was checked by finding the relative standard deviation. The developed method has been successfully employed for the determination of copper (II) in leafy vegetable and pharmaceutical samples and this method was inter comparison of experimental values using AAS.


2009 ◽  
Vol 6 (4) ◽  
pp. 1117-1120 ◽  
Author(s):  
A. Elphine Prabahar ◽  
B. Thangabalan ◽  
R. Kalaichelvi ◽  
P. Vijayaraj Kumar

A new simple, rapid, accurate, sensitive and precise spectrophotometric method in ultra violet region has been developed for determination of acipimox (ACX) in bulk and capsule dosage form. Acipimox exhibited maximum absorbance at 231 nm with apparent molar absorptivity of 1.5104 × 104in distilled water. Beer’s law was found to be obeyed in the concentration range 1-10 μg mL-1. Correlation coefficient was found to be 0.9998. The developed method was validated respect to linearity, precision, accuracy. The proposed method is useful for the routine estimation of ACX in bulk and capsule dosage form.


Author(s):  
Ratnamala P. Sonawane ◽  
R.S. Lokhande ◽  
Utkarsha M. Chavan

A spectrophotometric method has been developed for the determination of Cu(II) using 2-Hydroxy-1-Naphthalene carboxaldehyde phenyl hydrazone as an extractive reagent. The reagent forms a coloured complex, which has been quantitatively extracted into n-butanol at pH 9.2. The method obeys Beer’s law over arrange from 1 to 10 ppm. The Molar absorptivity and Sandell’s sensitivity were 0.97 × 104 L mol-1cm-1 and 0.26 µg·cm-2 respectively. The proposed method is very sensitive and selective. The method has been successfully applied to synthetic and commercial samples.


2010 ◽  
Vol 7 (3) ◽  
pp. 785-788 ◽  
Author(s):  
Mohammad Yunoos ◽  
D. Gowri Sankar ◽  
B. Pragati Kumar ◽  
Shahul Hameed ◽  
Azmath Hussain

A new, simple and sensitive spectrophotometric method in ultraviolet region has been developed for the determination of duloxetine hydrochloride in bulk and in pharmaceutical formulations. Duloxetine hydrochloride exhibits absorption maxima at 288 nm with apparent molar absorptivity of 0.97x104L/mol.cm in 0.1 N HCL. Beer's law was found to be obeyed in the concentration range of 5-30 μg/mL. The method is accurate, precise and economical. The proposed method has been applied successfully for the analysis of the drug in pure and in its capsule dosage forms. In this method, there is no interference from any common pharmaceutical additives and diluents. Results of the analysis were validated statistically and by recovery studies.


1992 ◽  
Vol 75 (6) ◽  
pp. 994-998 ◽  
Author(s):  
Ila T Patel ◽  
Muljibhai B Devani ◽  
Tushar M Patel

Abstract A simple, rapid, and specific method was developed for determination of cephalexin and its dosage forms. The method is based on the reaction of cephalexin with acetylacetone-formaldehyde reagent to give a yellow chromophore measurable at 400 nm. The color is stable for 3 h. Beer's law is valid within a concentration range of 10-100 μg/mL for cephalexin. All variables were studied to optimize the reaction conditions. The method is specific for amino β-lactam antibiotics. Non-amino β-lactam antibiotics do not interfere. No interference was observed in the presence of common pharmaceutical adjuvants. The validity of the method was tested by analyzing cephalexin tablets, capsules, and oral suspension. Good recoveries were obtained for these preparations. The results were comparable with those obtained by the official procedure


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