Tag Archives: UV spectrophotometry

Development and Validation of an UV-Spectrophotometric Method for the Assay of Strontium Ranelate and HPLC Stability Testing from Bulk and Pharmaceutical Dosage Form

DOI: 10.2478/amma-2019-0014

Objective: The present work offers a fast, reliable and easy UV spectrophotometric method for the assay of strontium ranelate from bulk samples and pharmaceutical dosage form.
Methods: The proposed method uses 0.1% V/V trichloroacetic acid as dissolution medium for spectrophotometric analysis, by signal detection at 321 nm. The method was validated according to the currently in-force international guidelines for linearity, accuracy, precision, robustness, limit of detection and quantification.
Results: The method was found to be linear in the range of 5-100 µg mL-1 (R2 > 0.999). Method accuracy was found in-between 98.87-100.41%, showing good linear correlation as well (R2 = 0.9997). The concentrations for limit of detection and limit of quantitation were found 1.13 µg mL-1 and 3.77 µg mL-1, resp. The proposed method showed good intra- and interday precision, with low RSD values of 0.53-1.24% and 1.11%, resp.
Conclusions: Stability studies performed by both HPLC and UV spectrophotometric methods revealed that the active substance is highly susceptible to acidic hydrolysis, oxidation and exposure to high temperature.

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Letrozole Determination by Capillary Zone Electrophoresis and UV Spectrophotometry Methods

DOI: 10.1515/amma-2017-0022

Objective: Letrozole is a highly potent oral nonsteroidal aromatase inhibitor triazole derivative. The aim of this study was to quantify letrozole from bulk, pharmaceutical formulation, and spiked urine samples by developing a simple, rapid and cost effective capillary electrophoresis method. Methods: A capillary zone electrophoresis method was optimized and validated. Additionally, an UV spectrophotometry method was used for comparing results. Results:The capillary zone electrophoresis method using a 90 mM sodium tetraborate background electrolyte proved to be an efficient method for determination of letrozole in a very short time, less than 2 minutes, using 20 kV voltage, 50 mbar/2 seconds pressure and 50°C temperature as optimum parameters. Additionally, the UV spectrophotometry method proved to be simple and efficient to quantify letrozole from bulk material and pharmaceutical formulation with linearity of response between 5 to 20 µg·mL-1 concentrations. For both methods, validation parameters, including linearity, detection and quantification limits were determined. Also we proved that our electrophoretic method has potential in analyzing letrozole from biological samples, obtaining encouraging results on estimation of letrozole from spiked urine samples without any special treatment. Conclusions: To quantify letrozole from bulk material, pharmaceutical preparations, and spiked urine samples the capillary zone electrophoresis method using a tetraborate sodium background electrolyte has proven to be simple and appropriate. Also a simple UV spectrophotometric method has been developed and validated for the same purposes.

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Simultaneous Determination of Atorvastatin and Amlodipine in Industrial Tablets by Apparent Content Curve and HPLC Methods

DOI: 10.2478/amma-2013-0010

Introduction: This study proposes the simultaneous determination of atorvastatin and amlodipine in industrial tablets by a quantitative spectrophotometric method, named the apparent content curve method, test method, and by an HPLC method with UV detection as reference method.
Materials and methods: A synthetic mixture and two fixed medicinal combinations containing amlodipine and atorvastatin were investigated by the apparent content curve method, a simple and relatively inexpensive UV-VIS spectrophotometric method based on a mathematical approach derived from the Lambert-Beer law. The results were compared with those obtained by an HPLC method.
Results: A good correlation of the results was obtained, the difference between the pair results was not significant (p >0.05).
Conclusions: The proposed spectrophotometric method is an easier and cheaper alternative for the quantitative determination of amlodipine and atorvastatin in industrial fixed-dose combinations.

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Quinolone Antibacterials: Commentary and Considerations Regarding UV Spectra and Chemical Structure

DOI: 10.1515/amma-2015-0084

Objective: Antibacterial quinolones represent an important class of pharmaceutical compounds that are widely used in therapy. Analytical methods that rely on their property to absorb light in the UV range are commonly used for their analysis. In the current study we present an interpretation of the relationship between chemical structure – UV spectra based on the comparative examination of UV spectral behavior of the eighteen quinolone derivatives and four model compounds.
Methods: Eighteen quinolone derivatives and four model compounds were selected and their UV spectra were recorded in different solvents (methanol, 0.1M HCl, 0.1M NaOH).
Results: The studied compounds show three absorption maximum values located around 210-230 nm, 270-300 nm and 315-330 nm values. A general characteristic was observed as the absorption bands exhibited both hypsochrome and bathochrome shifts, by comparison in different solvents. Most commonly we observed a slight hypsochrome shift at acidic pH (protonated form prevails) and basic pH (anionic form prevails). The structural differences are reflected in changes of UV spectra only when there are auxochrom substituents or different basic substituents are present in the quinolones structure.
Conclusions: The correlations between the chemical structure of quinolone derivatives and their UV spectra using model compounds were established. This study provides useful information that can be used successfully in various UV spectrophotometric analysis methods or in more complex analytical methods using UV detection, and also in pharmacodynamic and kinetic studies.

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