[Felodipine distribution in organisms of warm-blooded animals]

[Lercanidipine distribution in warm-blooded animals]

THE AIM OF THE STUDY

Is to investigate the lercadipine distribution in warm-blooded animals (rats). The experimental study used rats of Wistar race. TLC, GC-MS and UV-spectrophotometry methods were used for physical and chemical analysis. Semilethal (890 mg/kg) dose of lercadipine, previously suspended in water, was injected into stomach of laboratory animals. Examined substance was isolated from the thick tissues and animals' blood by acetone, cleaned with a change of solvent and macrocolumn chromatography using 30 µm «Silasorb S-18» sorbent and acetonitrile-water (8:2) polar eluent. The analyte was identified by chromatographic behavior in the thin sorbent layer, retention time and set of positive ions in its mass spectrum, as well as by UV-spectrum. The analyte was determined quantitatively in bioactive matrix using UV-spectrophotometry. The methods were validated by criteria of linearity, selectivity, accuracy, precision, detection limits and quantitative determination. The main content of lercanidipine (mg/100 g) was determined in the stomach content (198.183±29.541), the stomach (195.312±21.579), the small intestine (47.096±3.947), the spleen (38.952±3.532) and the liver (26.211±2.232).

Felodipine Determination by a CdTe Quantum Dot-Based Fluorescent Probe

In this work, a CdTe quantum dot-based fluorescent probe was synthesized to determine felodipine (FEL). The synthesis conditions, structure, and interaction conditions with FEL of CdTe quantum dots were analysed by fluorescence spectrophotometry, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), UV–visible spectroscopy, and TEM. The CdTe QD concentration was 2.0 × 10⁻⁴ mol/L. The amount of quantum dots controlled in the experiment was 0.8 mL. The controlled feeding ratio of N (Cd²⁺):N (Te²⁻):N (TGA) was 2:1:4, the heating temperature was 140 °C, the heating time was 60 min, and the pH of the QD precursor was adjusted to 11 for subsequent experiments. The UV–visible spectrum showed that the emission wavelength of CdTe quantum dots at 545 nm was the strongest and symmetric. The particle size of the synthesized quantum dots was approximately 5 nm. In the interaction of CdTe quantum dots with FEL, the FEL dosage was 1.0 mL, the optimal pH value of Tris-HCl buffer was 8.2, the amount of buffer was 1.5 mL, and the reaction time was 20 min. The standard curve of FEL was determined under the optimal synthesis conditions of CdTe quantum dots and reaction of CdTe quantum dots with FEL. The linear equation was Y = 3.9448x + 50.068, the correlation coefficient R2 was 0.9986, and the linear range was 5 × 10⁻⁶–1.1 × 10⁻⁴ mol/L. A CdTe quantum dot-based fluorescent probe was successfully constructed and could be used to determine the FEL tablet content.