scholarly journals Spectrophotometric determination of methyldopa in pharmaceutical preparation via ion pair formation

2019 ◽  
Vol 10 (2) ◽  
pp. 1367-1371
Author(s):  
Khalaf F Al Samarrai ◽  
Eman Thiab A Al Samarrai ◽  
Baidaa Adnan Al Samarrai
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
Pharmaceutical Preparation ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Ion Pair ◽  
Pair Formation ◽  
Limit Of Quantification ◽  
Ion Pair Formation

A simple, rapid and low-cost spectrophotometric method for determination of Methyldopa (MDA) based on ion-pair formation using Bromothymol blue (BTB) as a reagent in alkaline medium (pH 8.7). The absorbance of the green-blue-coloured product is measured at 616 nm. Beer's Law is obeyed at concentration range up to 5-20μg/ml with molar absorptivity 0.8279x104 L/mol.cm. The correlation coefficient, limit of detection and limit of quantification were 0.9982, 0.4318 μg/ml and 1.4393 μg/ml respectively. The method has been successfully applied to the determination of Methyldopa in pharmaceutical preparations.

scholarly journals Spectrophotometric method for determination of ranitidine hydrochloride in bulk and in pharmaceutical preparation using ninhydrin

2020 ◽  
Vol 11 (4) ◽  
pp. 291-297
Author(s):  
Hutaf Mustafa Baker ◽  
Hussam Ahmad Alsaoud ◽  
Hamzeh Mohamad Abdel-Halim
Keyword(s):  
Spectrophotometric Method ◽  
Limit Of Detection ◽  
Pharmaceutical Preparation ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Limit Of Quantification ◽  
Ranitidine Hydrochloride ◽  
Relative Standard ◽  
Reproducible Method

A simple, sensitive and reproducible method for the determination of ranitidine hydrochloride in pharmaceutical preparations was investigated. This spectrophotometric method was based on the formation of a deep red color product with ninhydrin in basic media and the absorbance measured at λmax = 480 nm. The reaction occurs at 45 °C with pH = 10 having a contact time of 38 minutes. Under the optimum conditions, Beer’s Law is obeyed in the concentration range of 8.98×103 - 9.90×104 µg/L. The coefficient of correlation was found to be 0.999 for the obtained method with molar absorptivity of 3.05×103 L/mol.cm. The calculated Sandell’s sensitivity is 0.108 μg/cm2. The limit of detection and limit of quantification are 0.0997 and 0.3023 µg/mL, respectively. The low values of the percentage relative standard deviation and percentage relative error indicate the high precision and the good accuracy of the proposed method. The stoichiometry of the reaction is determined and found to be 1:4 (Ranitidine hydrochloride:Ninhydrin). The initial rate method confirmed that this reaction is first order one.

scholarly journals Spectrophotometric determination of diclofenac in pharmaceutical preparations assisted by microwave oven

2005 ◽  
Vol 30 (1) ◽  
pp. 29-36 ◽  
Author(s):  
E. G. Ciapina ◽  
A. O. Santini ◽  
P. L. Weinert ◽  
M. A. Gotardo ◽  
H. R. Pezza ◽  
...  
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
Standard Procedure ◽  
Pharmaceutical Preparations ◽  
Magnesium Stearate ◽  
The United States ◽  
Molar Absorptivity ◽  
Heating Time ◽  
Limit Of Quantification

In this work, an effective and low-cost method for the determination of sodium or potassium diclofenac is proposed in its pure form and in their pharmaceutical preparations. The method is based on the reaction between diclofenac and tetrachloro-p-benzoquinone (p-chloranil), in methanol medium. This reaction was accelerated by irradiating of reactional mixture with microwave energy (1100 W) during 27 seconds, producing a charge transfer complex with a maximum absorption at 535 nm. The optimal reaction conditions values such as reagent concentration, heating time and stability of the reaction product were determined. Beer's law is obeyed in a concentration range from of 1.25x10-4 to 2.00x10-3 mol l-1 with a correlation coefficient of 0.9993 and molar absorptivity of 0.49 x10³ l mol-1 cm-1. The limit of detection (LOD) was 1.35x10-5 mol l-1 and the limit of quantification (LOQ) was 4.49x10-5 mol l-1. In the presence of the common excipients, such as glucose, lactose, talc, starch, magnesium stearate, sodium sulphite, titanium dioxide, polyethyleneglycol, polyvinylpirrolidone, mannitol and benzilic alcohol no interferences were observed. The analytical results obtained by applying the proposed method compare very favorably with those given by the United States Pharmacopeia standard procedure. Recoveries of diclofenac from various pharmaceutical preparations were within 95.9% to 103.3%, with standard deviations ranging from 0.2% to 1.8%.

UV-Visible Spectrophotometric Determination of Lambda-Cyhalothrin Insecticide in Vegetables, Soil and Water Samples

2019 ◽  
Vol 31 (1) ◽  
pp. 1-9
Author(s):  
Deepak Kumar Sahu ◽  
Joyce Rai ◽  
Chhaya Bhatt ◽  
Manish K. Rai ◽  
Jyoti Goswami ◽  
...  
Keyword(s):  
Crop Production ◽  
Limit Of Detection ◽  
Low Cost ◽  
Molar Absorptivity ◽  
Agricultural Field ◽  
Limit Of Quantification ◽  
Yellow Colour ◽  
Modern Age ◽  
Lambda Cyhalothrin

In modern age pesticide is used widely in agriculture. Lambda-cyhalothrin (LCT) is one of the most used pesticides which are used as a insecticide to kill pest, tricks, flies etc in agricultural field and it is also used for crop production. We have developed new method to detect LCT insecticide in agriculture field and reduce its uses. In this method we found the maximum absorbance at 460 nm for yellow colour dye. We also calculated limit of detection and limit of quantification 0.001 mg kg-1 and 0.056 mg kg-1 respectively. Molar absorptivity and Sandell’s sensitivity was also calculated and obtained 1.782 ×107 mol-1 cm-1 and 9.996 ×10-6 µg cm-2 respectively. The obtained yellow colour dye obeyed Beer’s law limit range of 0.5 µg ml -1 to 16 µg ml-1 in 25 ml. This method is less time consuming, selective, simple, sensitive and low cost. Present method is successfully applied in various soil, water and vegetable samples.

Rapid Colorimetric Assay of Trimethoprim and Sulfamethoxazole in Pharmaceuticals

1983 ◽  
Vol 66 (6) ◽  
pp. 1447-1449 ◽  
Author(s):  
Asis K Sanyal ◽  
Dinabandhu Laha
Keyword(s):  
Solvent Extraction ◽  
Colorimetric Assay ◽  
Pharmaceutical Preparations ◽  
Ion Pair ◽  
Pair Formation ◽  
Bromophenol Blue ◽  
Colorimetric Determination ◽  
Ion Pair Formation ◽  
Subsequent Measurement

Abstract A method is described for the direct colorimetric determination of trimethoprim and sulfamethoxazole in pharmaceutical preparations, without prior separation. Estimation of trimethoprim is based on its ion-pair formation with bromophenol blue and subsequent measurement of absorbance of the ionpair at 418 nm. Estimation of sulfamethoxazole is possible without removal of trimethoprim by solvent extraction.

scholarly journals Spectrophotometric and RP-HPLC Methods for Determining Cefotaxime Sodium in Pharmaceutical Preparations

2020 ◽  
Vol 32 (6) ◽  
pp. 1314-1320
Author(s):  
Lamya A. Sarsam ◽  
Salim A. Mohammed ◽  
Sahar A. Fathe
Keyword(s):  
Limit Of Detection ◽  
Phosphate Buffer Solution ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Hplc Method ◽  
Buffer Solution ◽  
Limit Of Quantification ◽  
Rp Hplc ◽  
Relative Standard

A rapid, simple and sensitive spectrophotometric and RP-HPLC methods have been developed for the quantitative determination of cefotaxime-Na in both pure and dosage forms. The spectrophotometric method was based on diazotization of cefotaxime-Na and then coupling with 8-hydroxyquinoline in an alkaline medium. The resulting azo dye exhibited maximum absorption at 551 nm with a molar absorptivity of 0.597 × 104 L mol-1 cm-1. Beer′s law was obeyed over the range 10-700 μg/25 mL (i.e. 0.4-28.0 ppm) with an excellent determination coefficient (R2 = 0.9993). The limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.0194 and 0.3765 μg mL-1, respectively. The recoveries were obtained in the range 97.3-102.5% and the relative standard deviation (RSD) was better than ± 1.56. The HPLC method has been developed for the determination of cefotaxime-Na. The analysis were carried out on a C18 column and a mobile phase composed of acetonitrile and phosphate buffer solution (0.024M KH2PO4 and 0.01M H3PO4) at pH 3.5 in the ratio of 60:40 (v:v), with a flow rate of 1.0 mL min-1 and UV detection at 258 nm. The proposed method showed good linearity (in a range of concentration 1.0-200 μg mL-1. The recovery percent and a relative standard deviations were found in the range 96 to 104.8% and ± 0.017 to ± 0.031%, respectively. Both methods were applied successfully to the assay of cefotaxime-Na in commercial injection preparations.

scholarly journals Spectrophotometric Determination of Certain Antiepileptic's in Tablets Using Vanillin Reagent

2016 ◽  
Vol 11 (2) ◽  
pp. 3540-3551
Author(s):  
Taghreed A. Mohammed ◽  
Mona A. Mohamed
Keyword(s):  
Limit Of Detection ◽  
Low Cost ◽  
Coupling Reaction ◽  
Molar Absorptivity ◽  
Limit Of Quantification ◽  
Drug Products ◽  
Significant Difference ◽  
Student’S T ◽  
Comparison Of The Results

A selective and new spectrophotometric method is described for determination of three antiepileptic drugs; namely lamotrigine (LAM), gabapentin (GAB), and oxcarbazepine (OXC) in drug substances and in drug products using vanillin reagent as the chromogenic agent. The method is based on a coupling reaction between the cited drugs and vanillin reagent in acidic condition. Under optimized conditions, the yellow colored products were measured at 405, 396, and 400 nm respectively. Beer’s law was obeyed at (0.4 – 10), (0.1-10), and (0.5-11) μg/mL, and  the calculated molar absorptivity values are 2.52 x 104, 1.74 x 104, and 2.54 x 104 L/mol/cm for LAM, GAB, and OXC respectively. Sandell sensitivity, the limit of detection (LOD) and limit of quantification (LOQ) were calculated. No interference was observed from common additives found in drug products. The presented method was validated according to ICH guidelines. Statistical comparison of the results was performed using Student's t-test and F-ratio at 95% confidence level, and there was no significant difference between the reference and proposed method with regard to accuracy and precision. The method offers the advantages of rapidity, simplicity and sensitivity and low cost and can be easily applied to resource poor settings without the need for expensive instrumentation and reagents.

scholarly journals Spectrophotometric determination of promethazine HCl in pure and dosage forms

2019 ◽  
Vol 13 (1) ◽  
pp. 52-57
Author(s):  
Rawa M. Tagi ◽  
Raad J. Al-Timimi ◽  
Muna M. Hassan ◽  
Mohammed J. Hamzah
Keyword(s):  
Limit Of Detection ◽  
Reaction Medium ◽  
Pharmaceutical Preparations ◽  
Molar Absorptivity ◽  
Organic Reagent ◽  
Coupling Reactions ◽  
Oxidizing Agent ◽  
Limit Of Quantification ◽  
Stability Time

Background: The research is involved development a new spectrophotometric method based on the oxidative coupling reactions for determination of important phenothiazine drug which is promethazine HCl in pure solutions and local pharmaceutical preparations. Materials and methods: The Standard promethazine HCl was treated with organic reagent of P-Chloroaniline as a coupling reagent in the presence of oxidizing agent Ammonium Cerric (IV) Sulphate, the reaction leads to the formation a blue –greenish color product that has a maximum absorption at 603nm. Results: The variables of reaction conditions including optimum volumes of both reagent and oxidizing agent, acidity of the reaction medium, order of addition and stability time were studied. The obtained results of the purposed method shows that a Beer law is obeyed in the range of 7-40ppm with a correlation coefficient (r2) of 0.9981. While the molar absorptivity (ξ) of 1.861x103 L.mol-1.cm-1, sandal sensitivity(s) of 0.172μg.cm-2, limit of detection (LOD) of 4.02ppm and limit of quantification (LOQ) of 13.39ppm were obtained. The developed method was compared with the standard method adopted by USP using F and t-tests and the results shows no significant deferent between both methods. Conclusion: The analytical method was also applied successfully for pharmaceutical preparations containing promethazine HCl.

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