Kinetic spectrophotometric method for determination of amlodipine besylate in its pharmaceutical tablets

Fine-tuning Fluorescence of Amlodipine Adopting on Blocking of Photoinduced Electron Transfer (PET): Application in Human Plasma

Assessing medication adherence through the determination of antihypertensive drugs in biological matrices holds significant importance. Amlodipine (AP), a potent antihypertensive medication extensively prescribed for hypertensive patients, is particularly noteworthy in this context. This article aims to introduce a rapid, simple, improved sensitivity, and reproducibility in detecting AP in its pure form, tablet formulation, and spiked human plasma than the other reported methods. The proposed method utilizes a fluorescence approach, relying on the inhibition of the intramolecular photoinduced electron transfer (PET) effect of the lone pair of the N-atom in the primary amino moiety of AP. This inhibition is achieved by acidifying the surrounding medium using 0.2 M acetic acid. By blocking PET, the target AP drug is sensitively detected, at [Formula: see text] 423 nm over a concentration range 25-500 ng mL- 1 showcasing an exceptionally low quantitation limit of 1.41 ng mL- 1. Notably, this innovative technique was successfully applied to detect AP in its solid dosage form and spiked human plasma. Remarkably, matrix interference was found to be insignificant, underscoring the robustness and applicability of the established approach. The combination of speed, sensitivity, and reproducibility makes this method particularly suitable for assessing medication adherence in patients prescribed AP for hypertension.

New Derivatization Methodology of 4-aminobenzoic Acid from its Dietary Supplements: Kinetic Spectrophotometric Methods for Determination

Background:

A new approach describing the validation and development of an easy, new spectrophotometric and kinetic method for identification of para-aminobenzoic acid in dietary supplement has been performed. In this study, para-aminobenzoic acid was derived in a pH-controlled environment, as a new organic compound 4(4-Benzophenylazo)pyrogallol, by incorporating diazotized para-aminobenzoic acid with pyrogallol.

Objective:

The determination of para-aminobenzoic acid was conducted by the fixed time and initial rate techniques. These approaches were based on the reaction of the compound containing paraaminobenzoic acid, 4(4-Benzophenylazo)pyrogallol, with Ag(I) to form colored product with a maximum absorbance at 468nm. Both of these techniques were adopted for constructing the calibration curves and examined for their suitability for the quantitation of para-aminobenzoic acid in dietary supplement.

Methods:

The determination process was established, using initial rate and fixed time kinetic spectrophotometric methods.

Results:

4(4-Benzophenylazo)pyrogallol was characterized using proton-nuclear magnetic resonance, Fourier-transform infrared, differential scanning calorimetry and thermogravimetric thermal methods, gas chromatography–mass techniques, and solvatochromic behavior in solvents with different polarities was also examined.

Conclusion:

For the first time, para-aminobenzoic acid was well determined by incorporating it as an organic solid compound, 4(4-Benzophenylazo)pyrogallol, through coupling pyrogallol with diazotized para-aminobenzoic acid in regulated pH medium, ranging between 5.0 to 6.0. The existence of common excipients in the dietary supplement did not produce any significant interference. F- and ttest data analysis were used for statistical comparison of the suggested techniques with that of reference method, demonstrating excellent agreement with no significant difference in the associated precision and accuracy.

New approach for determination of sulfadiazine in pharmaceutical preparations using 4(4-sulphophenylazo)pyrogallol: Kinetic spectrophotometric method

A new trend describes the development and validation of a simple, sensitive and selective kinetic spectrophotometric methods for the determination of sulfadiazine in pharmaceutical formulations has been conducted. In this paper, sulfadiazine was derivatized as a new organic compound 4(4-sulphophenylazo) pyrogallol, 4-SPAP, by coupling pyrogallol with diazotized sulfadiazine in medium of controlled pH. 4-SPAP was characterized by techniques of FT-IR, H-NMR, GC-Mass, TG and DSC thermal analysis methods. Solvatochromic behavior in solvents of various polarities was also investigated. The determination of sulfadiazine was accomplished by initial rate and fixed time methods. These methods were based on the reaction of the compound containing sulfadiazine, 4-SPAP, with Ca(II) to form colored product with a maximum absorbance at 520 nm. The two methods were adopted for constructing the calibration curves and examined for their suitability for the quantitation of sulfadiazine in pharmaceuticals. The limit of detection (LOD) and limit of quantification (LOQ) were found to be, by initial rate method, 0.35 and 1.05 μg·mL^-1and that by fixed time method were found to be 0.69 and 2.07 μg·mL^-1, respectively. The percent relative standard deviations (%RSD) for the results ranged from 1.04% to 1.76% and 0.85% to 1.42% for the initial rate and fixed time methods of the proposed kinetic spectrophotometric method, respectively. The existence of common excipients in the pharmaceutical formulation did not produce any significant interference. Statistical comparison was reported as indicated from the F- and t-test data of the proposed methods with that of reference method showing excellent agreement and indicating no significant difference in their accuracy and precision.