Supercritical fluid (SFC), green chromatography
One of the main objectives of this study is to find an analysis method that has a low environmental and health impact and contributes to achieving sustainability. A simple and sensitive method was established for determination of lacidipine in pure active pharmaceutical ingredient, pharmaceutical formulation and spiked human plasma in presence of its acid induced degradation product. The native emission was measured at 430 nm after the excitation at 281 nm. A 0.5% Tween-80 solution was used to enhance fluorescence intensity. Peak amplitude of the first derivative synchronous was measured at 409 nm by using constant wavelength difference (Δλ = λem - λex = costant) which equal 160 nm. The regression plot of the proposed first derivative synchronous spectrofluorimetric method was found to be linear over the range of 50–300 ng/mL with a determination coefficient equals 0.9997, limit of detection (LOD) was 14.51 ng/mL but limit of quantification (LOQ) was 43.97 ng/mL.
Lacidipine is diethyl (E)−4-{2-\[(tert-butoxycarbonyl)vinyl]phenyl}−1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate as in Fig. 1. Lacidipine is a calcium channel blocker used as an antihypertensive drug. The reported analytical methods for determination of lacidipine in biological samples and pharmaceutical formulations include LC-MS/MS, HPLC, UV spectrophotometry, and other methods. The British Pharmacopoeia shows that it melts at 178 °C and describes a gas chromatographic method for separation along with its chromatographic conditions.
Fluorescence spectrometry is an essential analytical technique for chemical quantification because of its great sensitivity. Overlapping broadband spectra may cause problems with the selectivity of multicomponent analysis. The frequent occurrence of fluorescence spectrum overlapping problems limits the use of spectrofluorimetry for multicomponent measurement. The synchronous detection mode, which examines the excitation and emission spectra simultaneously, might help address this issue. This method enhances band resolution by decreasing overlap and narrowing spectral bands. Furthermore, the resolution and selectivity of synchronous spectra can be improved by applying mathematical derivatisation techniques such as first- or second-order derivatives. When combined, these techniques increase the clarity and precision of the analysis.
The fluorescence spectra of lacidipine and its degradation product showed considerable overlap when they were first observed. The authors are therefore urged to develop a first derivative synchronous spectrofluorimetric method to enable simultaneous determination of the drug and its degradation product in different matrices.
For further reading please visit: 10.1038/s41598-025-11341-y
Product directory
