Pharmacokinetic study of hypaphorine, a potential agent for treating osteoclast-based bone loss, on rats using LC-MS/MS

Aim and Objective: A high-performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of hypaphorine, a potential agent for treating osteoclast-based bone loss, was developed and valadated in rat plasma. Materials and Methods: Plasma samples were pretreated by the protein precipitation. Chromatographic separation was performed using an Inertsil ODS-3 column (50 mm × 4.6 mm, 5 μm). The mobile phase consisted of water (containing 0.1% formic acid) and acetonitrile in a gradient mode at a flow rate of 0.5 mL/min. The acquisition was carried out in selected reaction monitoring (SRM) of the transitions from protonated precursor ion [M + H]+ to the particular daughter ion and the mass transitions of hypaphorine and IS were 247 → 188 and m/z 219 → 188, respectively. The method was validated in terms of selectivity, linearity, accuracy and precision, extraction recovery and matrix effect, stability and carryover. Results: It showed good linearity over the range of 1-2000 ng/mL (R2 = 0.9978). The intra-batch accuracy was within 93.95-105.81% and the precision was within 4.92-11.53%. The inter-batch accuracy was within 96.18-100.39% with a precision of 6.22-11.23%. The extraction recovery and matrix factors were acceptable. Conclusion: The simple and rapid method was successfully applied to the pharmacokinetics study in rats following oral administration of hypaphorine at the doses of 0.5, 1.5, and 4.5 mg/kg.

Economic Spectrofluorometric Bioanalysis of Empagliflozin in Rats’ Plasma

A simple, economic, green, and sensitive bioanalytical method for empagliflozin bioassay in rats’ plasma was employed successfully owing to the empagliflozin native fluorescence behavior. Enhanced liquid-liquid extraction, using diethyl ether (DEE), was successfully employed for the improved extraction of empagliflozin from rats’ plasma based on its high value of logP as 1.8 that boosted the drug migration from plasma to the organic layer. The relative fluorescence intensity for empagliflozin was recorded at emission (299.4 nm) after excitation at 226.5 nm. The method was validated with satisfactory results for linearity (500–5000 ng/mL), trueness, precision, the matrix effect, and extraction recovery. The matrix effect ranged between 15.63% and 23.10% for LQC and HQC samples, respectively. Extraction recovery ranged between 54.61% and 62.54% for LQC and HQC samples, respectively. Bias values for the trueness ranged between −10.62 and +14.95, while %RSD values for the precision ranged between 5.39% and 9.33%. The method was successfully applied to rats’ plasma samples that included six rats, and the drug concentration was determined in their plasma after 1 hour (estimated Cmax based on literature) following oral administration of empagliflozin with a concentration of 10 mg/Kg, p.o.. The developed cost-effective spectrofluorimetric method in the present work will be of beneficial use in further pharmacokinetic studies that include rats’ plasma and biological fluids. Moreover, with the suitable modifications, the described novel extraction of empagliflozin could be adopted to human plasma samples and future clinical studies. Moreover, development of new simple cost-effective methods is necessary to give the researchers a set of “varieties” that they can use according to the laboratory limitations, especially in the developing countries in addition of being a greener method due to the lower consumption of toxic solvents and lower waste production.

LC–MS/MS analysis and pharmacokinetics of daidzein and its 7-O-glucuronide in rats after oral administration of 7-O-L-valyl carbamate prodrug

Background: A valine carbamate prodrug (7-P) was designed to enhance the low bioavailability of daidzein due to its low water solubility and membrane permeability. Here, we developed a high-throughput HPLC–MS/MS method to measure daidzein and its 7-O-glucuronide after oral administration of daidzein or 7-P. Materials & methods: A HPLC–MS/MS method was validated and successfully applied to assess the pharmacokinetic behavior of daidzein and its 7-O-glucuronide after orally administrating daidzein or 7-P. The validated method on selectivity, linearity (r ≥ 0.995), precision (relative standard deviation <11.4%), accuracy (relative error <7.1%), extraction recovery (>92.4%), matrix effect (<8.2%) and stability were satisfied. Conclusion: The proposed economical, rapid and sensitive method will be an alternative analytical procedure for daidzein and its metabolite in biological samples.

Extraction Recovery of Vanadium(V) by Amines

The extraction of vanadium (V) by N-(2-hydroxy-5-nonylbenzyl)-β, β- dihydroxyethylamine was studied depending on different factors, such as pH of the medium, concentration of extracting agent, temperature and solvent type. This allowed the optimal extraction conditions to be determined. It was shown that extraction of vanadium (V) takes place with high distribution coefficients, and a complex containing a decavanadate anion and four molecules of the extractant is formed in the organic phase. The extracted vanadium (V) complex with amine is stable for more than one month. Keywords: extraction, vanadium, distribution coefficient, infrared spectroscopy

Microalgae Biomolecules: Extraction, Separation and Purification Methods

Several microalgae species have been exploited due to their great biotechnological potential for the production of a range of biomolecules that can be applied in a large variety of industrial sectors. However, the major challenge of biotechnological processes is to make them economically viable, through the production of commercially valuable compounds. Most of these compounds are accumulated inside the cells, requiring efficient technologies for their extraction, recovery and purification. Recent improvements approaching physicochemical treatments (e.g., supercritical fluid extraction, ultrasound-assisted extraction, pulsed electric fields, among others) and processes without solvents are seeking to establish sustainable and scalable technologies to obtain target products from microalgae with high efficiency and purity. This article reviews the currently available approaches reported in literature, highlighting some examples covering recent granted patents for the microalgae’s components extraction, recovery and purification, at small and large scales, in accordance with the worldwide trend of transition to bio-based products.