scholarly journals Kinetic Spectrophotometric Determination of the Macrolide Antibiotic Josamycin in Formulations

2003 ◽  
Vol 86 (3) ◽  
pp. 484-489 ◽  
Author(s):  
Abdulrahman A Al-Majed ◽  
Fathalla Belal ◽  
Kamal E E Ibrahim ◽  
Nasr Y Khalil

Abstract A simple kinetic spectrophotometric method was developed for the determination of josamycin in its dosage forms. The method is based on oxidation of the drug with alkaline potassium permanganate at room temperature for a fixed time of 20 min and measuring the produced green color at 611 nm. The absorbance–concentration plot is rectilinear over the range of 2–10 μg/mL (2.4 × 106–1.2 × 10−5M) with minimum detectability of 1.0 μg/mL (1.2 × 10−6M). The determination of josamycin by fixed concentration and the rate-constant methods is also feasible with the calibration equations obtained, but the fixed-time method proved to be more applicable. The procedure was applied successfully to commercial tablets, and statistical analysis showed that the results compared favorably with those obtained by reference methods. The effect of sensitizers and surfactants on the performance of the proposed method was also studied. A proposal of the reaction pathway was presented.

2002 ◽  
Vol 85 (4) ◽  
pp. 817-823 ◽  
Author(s):  
Sheikha M Al-Ghannam ◽  
Fathalla Belal

Abstract A simple kinetic procedure is described for the determination of atenolol in its dosage forms. The procedure is based on coupling the drug with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole in pH 8 borate buffer at the boiling temperature for a fixed time of 30 min, and then measuring the absorbance of the reaction product at 460 nm. The absorbance–concentration plot is rectilinear over the range 5–50 μg/mL with a minimum detection limit of 1.3 μg (4.9 × 10−6M). The determination of atenolol by the fixed-concentration and rate-constant methods is also feasible with the calibration equations obtained, but the fixed-time method proved to be more applicable. The procedure was applied successfully to commercial tablets, and statistical analysis showed that the results compared favorably with those obtained by the official methods. The interference likely to be introduced from some coformulated drugs and the effect of sensitizers and surfactants on the performance of the proposed method were also studied. A proposed reaction pathway is presented.


2004 ◽  
Vol 87 (2) ◽  
pp. 352-359 ◽  
Author(s):  
Abdulrahman A Al-Majed ◽  
Fathalla Belal ◽  
Nasr Y Khalil ◽  
Kamal E E Ibrahim

Abstract A simple kinetic spectrophotometric method was developed for the determination of josamycin in its dosage forms and spiked human plasma. The method is based on reaction of the drug with 3-methylbenzothiazolin-2-one hydrazone/ferric chloride system for a fixed time of 20 min at 70°C and measuring the produced color at 665 nm. The absorbance-concentration plot is rectilinear over the range of 5.0–30.0 μg/mL with detection limit of 1.0 μg/mL (1.2 × 10−6M). The determination of josamycin by the fixed concentration and the rate-constant methods is also feasible with the calibration equations obtained, but the fixed-time method proved to be more applicable. The procedure was successfully applied to commercial tablets. The results obtained were favorably compared with those given by reference methods. The method was further extended to the in vitro determination of josamycin in spiked human plasma. The recovery (n = 8) was 100.76 ± 3.43%. The stoichiometry of the reaction between the drug and the reagent was studied by adopting the limiting logarithmic method, and a proposal of the reaction pathway was presented.


2000 ◽  
Vol 68 (2) ◽  
pp. 173-188 ◽  
Author(s):  
M. Rizk ◽  
F. Belal ◽  
F. Ibrahim ◽  
S. M. Ahmed ◽  
N. M. El-Enany

An accurate simple and selective kinetic procedure for the determination of certain 4-quinolones namely, norfloxacin (I), ofloxacin (II), enrofloxacin (III), fleroxacin (IV), ciprofloxacin (V) and pefloxacin (VI) is described. The procedure is based on reacting the studied compounds in acidic media (0.1 M HCL) with 3-methyl-2-benzothiazolinone hydrazone hydrochloride (MBTH) in presence of cerium (IV) ammonium sulphate as an oxidant at room temperature for a fixed time of 20 min. for (I), (III), 12 min for (II) and 30 min for IV , V and VI, then the absorbance of the reaction product is measured at 630 nm. The concentration of the studied compounds is computed using the corresponding calibration curve equation for the fixed-time method. The absorbance-concentrations plot is rectilinear over the range 20-100 ug.ml-1 for (I), 2 - 20 ug.ml-1 for (II), 10 - 74 ug.ml-1 for (III), 10 - 60 ug.ml-1 for IV, 10 - 50 ug.ml-1 for IV and 8 - 40 ug.ml-1 for VI. The determination of the studied compounds by the fixed-concentration and rate constant methods is feasible with the calibration equation obtained, but the fixed-time method proved to be more applicable. The procedure was applied successfully to commercial tablets and ampoules and the results obtained were compared statistically with the reference methods.


Author(s):  
Akram M. El-didamony ◽  
Moftah A. Moustafa

Objective: Direct and sensitive spectrophotometric method is described for the quantitative determination of some anti-hypertensive drugs such as atenolol (ATN) and timolol (TIM) in pure forms as well as in their dosage forms.Methods: The proposed method is based on the redox reaction between the selected drugs and KMnO4 in alkaline medium. The method involves treating the aqueous solution of the selected drugs with KMnO4 in alkaline medium and measuring the bluish-green product at 610 nm. The different experimental parameters affecting the development and stability of the color were carefully studied and optimized.Results: The fixed-time method is adopted for constructing the calibration curves, which were found to be linear over the concentration ranges of 2.0–14 mg/ml and 2.0–28 mg/ml for ATN and TIM, respectively. The determination of the studied drugs by initial rate, variable time and rate constant method was workable with the calibration equations obtained but the fixed time method has been found to be more applicable.Conclusion: The applicability of the proposed method was demonstrated by the determination of the selected drugs in both pure and in commercial dosage forms and has met the validation requirements.


2009 ◽  
Vol 2009 ◽  
pp. 1-11 ◽  
Author(s):  
Ashraf M. Mahmoud

New rapid, sensitive, and accurate kinetic spectrophotometric methods were developed, for the first time, to determine omeprazole (OMZ) in its dosage forms. The methods were based on the formation of charge-transfer complexes with both iodine and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ). The variables that affected the reactions were carefully studied and optimized. The formed complexes and the site of interaction were examined by UV/VIS, IR, and1H-NMR techniques, and computational molecular modeling. Under optimum conditions, the stoichiometry of the reactions between OMZ and the acceptors was found to be 1 : 1. The order of the reactions and the specific rate constants were determined. The thermodynamics of the complexes were computed and the mechanism of the reactions was postulated. The initial rate and fixed time methods were utilized for the determination of OMZ concentrations. The linear ranges for the proposed methods were 0.10–3.00 and 0.50–25.00   with the lowest LOD of 0.03 and 0.14   for iodine and DDQ, respectively. Analytical performance of the methods was statistically validated; RSD was <1.25% for the precision and <1.95% for the accuracy. The proposed methods were successfully applied to the analysis of OMZ in its dosage forms; the recovery was 98.91–100.32%  0.94–1.84, and was found to be comparable with that of reference method.


2002 ◽  
Vol 85 (6) ◽  
pp. 1316-1323 ◽  
Author(s):  
Mohamed I Walash ◽  
Fathalla Belal ◽  
Fawzia Ibrahim ◽  
Mohamed Hefnawy ◽  
Manal Eid

Abstract An accurate and simple kinetic method is described for the determination of ranitidine and nizatidine in pure form and in pharmaceuticals. The method is based on the reaction of the compounds with 7-chloro-4-nitrobenz-2-oxa-1,3-diazole in pH 7.4 borate buffer at 60°C for a fixed time of 25 min for both compounds. The absorbance of the reaction product is measured at 495 nm for ranitidine and nizatidine. Calibration graphs were linear over the concentration range of 2–20 μg/mL, with limits of detection of 0.13 (3.7 × 10−7M) and 0.25 μg/mL (7.5 × 10−7M) for ranitidine and nizatidine, respectively. The proposed method was applied successfully to the determination of ranitidine in tablets and ampoules with average recoveries of 100.26 ± 0.69 and 100.29 ± 0.59%, respectively, and to the determination of nizatidine in capsules with an average recovery of 104.26 ± 0.44%. The results obtained are in good agreement with those obtained by the other methods used for comparison. A proposal of the reaction pathway is also presented.


2006 ◽  
Vol 71 (10) ◽  
pp. 1107-1120 ◽  
Author(s):  
Nafisur Rahman ◽  
Zehra Bano ◽  
Hejaz Azmi ◽  
Mohammad Kashif

Asimple kinetic spectrophotometric method has been developed for the determination of lansoprazole in pharmaceutical formulations. The method is based on the oxidation of the drug with alkaline potassium permanganate at room temperature. The reaction was followed spectrophotometrically by measuring the increase in the absorbance owing to the formation of MnO 42? at 610 nm (Method A) and the decrease in the absorbance at 530 nm due to the disapperance of MnO4? (Method B). Calibration procedures were adopted for the assay of the drug. The calibration curves were linear over the concentration ranges of 5-150 and 5-70?g ml-1, with the corresponding calibration Equations: rate = -3.915x10-6 + 5.271x10-5 c and ?A = 1.04x 10-3 + 1.78x10-3 c for methods A, and B, respectively. A statistical comparison of the results of the proposed procedures with those of the reference spectrophotometric method show excellent agreement and indicated no significant difference between the compared methods in terms of accuracy and precision. Interval hypothesis tests were also performed, which indicated that the true bias of all samples was less than ? 2 %. .


Author(s):  
MARWA K. A. L. JAMAL

Objective: Development and validation of a sensitive, indirect spectrophotometric kinetic method, based on oxidation-reduction reaction, using potassium permanganate, for the quantitative assay of pitavastatin calcium, a cardiovascular drug used for the treatment of hyperlipidemia. Methods: The developed spectrophotometric kinetic method is based on the ability of potassium permanganate to oxidize Pitavastatin, where, the drug solution is treated with a fixed concentration of permanganate in acidic medium, and after a specified time, the unreacted permanganate is measured at 525 nm. All variables affecting the color development have been investigated and the conditions were optimized. Different kinetic methods, including initial rate, rate constant, fixed time and fixed concentration, were applied for the determination Pitavastatin. Results: During the course of the reaction, the absorbance values, at 525 nm, related to KMnO4, decreased linearly with increasing the concentration of the drug. The reaction rate obeyed was found to be pseudo-first-order and the kinetic method used was the fixed-time method. The assay of PITA in the concentration range of 16-80 μg/ml, using the fixed time method was successfully determined with a correlation coefficient value of 0.9999. The applicability of the developed method was also demonstrated by the determination of pitavastatin in its pure form and in its pharmaceutical formulation, where, the effect of excipients has also been studied and found to have no effect. Conclusion: The developed indirect spectrophotometric kinetic method, using the fixed time method, was used for the determination of Pitavastatin in pharmaceutical tablets. This method was simple, accurate and easy to apply for routine assay and in quality control laboratories.


2000 ◽  
Vol 68 (3) ◽  
pp. 281-296 ◽  
Author(s):  
Ekram M. Hassan ◽  
Mohammed E.M. Hagga ◽  
Haya I. Al Johar

An accurate kinetic method for the determination of cisapride is described. The method is based on the reaction of cisapride with potassium dichromate in 2.5 M sulphuric acid at room temperature for a fixed-time of 10 min, afterwards the absorbance of the reaction product is measured at 527 nm. The concentration of cisapride is computed using the corresponding calibration equation for the fixed-time method. The method is applied successfully to commercial tablets and oral suspension dosage forms. The results obtained are compared statistically with the British Pharmacopoeia method. The determination of cisapride by other kinetic methods is feasible with calibration equation obtained but the fixed-time method proves to be more applicable.


Author(s):  
Mouhammed Khateeb ◽  
Basheer Elias ◽  
Fatema Al Rahal

A simple and sensitive kinetic spectrophotometric method has been developed for the determination of folic acid (FA) in bulk and pharmaceutical Formulations. The method is based on the oxidation of FA by Fe (III) in sulfuric acid medium. Fe (III) subsequently reduces to Fe (II) which is coupled with potassium ferricyanide to form Prussian blue. The reaction is followed spectrophotometrically by measuring the increase in absorbance at λmax 725 nm. The rate data and fixed time methods were adopted for constructing the calibration curves. The linearity range was found to be 1–20 μg mL-1 for each method. The correlation coefficient was 0.9978 and 0.9993, and LOD was found to be 0.91 and 0.09 μg mL-1 for rate data and fixed time methods, respectively. The proposed method has been successfully applied to the determination of FA in formulations with no interference from the excipients. Statical comparison of the results shows that there is no significant difference between the proposed and pharmacopoeial methods


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