Sensitive determination of terazosin in pharmaceutical formulations and biological samples by ionic-liquid microextraction prior to spectrofluorimetry

Hytrin loaded polydopamine-serotonin nanohybrid induces IDH2 mediated neuroprotective effect to alleviate Parkinson's disease

Parkinson's disease (PD) is the second most neurodegenerative disease caused due to synucleinopathy leads to the death of dopaminergic and serotonergic neurons. The approach to reduce synucleinopathy paves the therapeutic way in PD management. Recent studies highlight anti-Parkinsonism effect of Hytrin that regulates energy homeostasis via activation of mitochondrial redox regulator; IDH2 leading to attenuation of synucleinopathy. However, the burst release kinetics of Hytrin restricts its therapeutic potential. Therefore, we aimed to improve Hytrin release kinetics through nanocarrier mediated delivery, replenish dopamine and serotonin by formulating Hytrin loaded polydopamine serotonin nanohybrid for PD protection. Present study also explores IDH2 mediated neuroprotective action in retardation of synucleinopathy for PD prevention. Nanoformulation has shown effective neurotherapeutic potential by improving Hytrin release profile in the reduction of PD symptoms in vitro and ex vivo. The neuroprotective effect has been attributed to IDH2 induction and alpha-synuclein reduction against rotenone insults. The direct physical interaction of IDH2 and alpha-synuclein, PD hallmark has been uncovered. The study divulges that the restorative effect of our nanoformulation significantly retards the PD deficits byinducing IDH2 mediated alpha-synuclein ubiquitination and proteasomal degradation pathway.

Simple and fast LC-MS/MS method for quantification of terazosin in human plasma and application to bioequivalence study

A simple, fast and sensitive LC-MS/MS method was developed to quantify terazosin in human plasma. The mobile phase consisted of acetonitrile-0.1% (v/v) formic acid (70:30, v/v). Prazosin was used as internal standard (IS). As deproteinization agent, acetonitrile produced a clean sample. A higher response intensity with more symmetrical peak was obtained using Agilent Poroshell 120 EC-C18 - Fast LC column (100 × 2.1mmID, 2.7 μm) compared with Kinetex XB-C18 (100 × 2.1 mm, 2.6 µm) column. The response of terazosin and IS were approximately two times in citrate phosphate dextrose (CPD) plasma compared with dipotassium ethylenediaminetetraacetic acid (K₂EDTA) plasma. Plasma calibration curve was linear from 1.0 to 100.0 ng/mL, with coefficient of determination r² ≥ 0.99. The within-run and between-run precision values (CV, %) were <5.2% and <7.8%, while accuracy values were 102.8-112.7% and 103.4-112.2%. The extended run accuracy was 98.6-102.8% and precision (CV, %) 4.3-10.4%. The recovery of analyte was >98% and IS >94%. Terazosin in plasma kept at benchtop was stable for 24 h, in autosampler tray for 48 h, in instrumentation room for 48 h, for 7 freeze-thaw cycles and in freezer for 140 days. Terazosin and IS stock standard solutions were stable for 140 days at room temperature and in the chiller. The high throughput method was successfully utilized to measure 935 samples in a bioequivalence study of terazosin.

Magnetic-Dispersive Solid Phase Extraction Based on Graphene Oxide-Fe3O4 Nanocomposites Followed by High Performance Liquid Chromatography-Fluorescence for the Preconcentration and Determination of Terazosin Hydrochloride in Human Plasma

In the present study, a facile modified impregnation method was employed to synthesize superparamagnetic graphene oxide-Fe3O4 (GO-Fe3O4) nanocomposites. Based on the GO-Fe3O4 as adsorbent, a simple and fast magnetic-dispersive solid phase extraction followed by high performance liquid chromatography with fluorescence detection (M-dSPE-HPLC-FL) method was established and validated for the preconcentration and determination of terazosin hydrochloride (TRZ) in human plasma samples. The obtained nanomaterials were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy and vibrating sample magnetometry. Different parameters affecting the extraction efficiency, such as sample pH, amount of sorbent, extraction time, elution solvent and its volume and desorption time, were evaluated and optimized. The linearity of the proposed method was excellent over the range 0.3-50.0 ng mL-1 with an acceptable coefficient of determination (R2 = 0.9989). The limit of quantification and limit of detection were found to be 0.3 and 0.09 ng mL-1, respectively, and the preconcentration factor of 10 was achieved. Intra- and inter-day precision expressed as relative standard deviation (RSD %, n = 6) were between 2.2-3.8% and 4.7-6.4%, respectively. Accuracy, estimated by recovery assays, was 97.7-106.6% with RSD ≤ 5.2%. Ultimately, the applicability of the method was successfully confirmed by the extraction and determination of TRZ in human plasma samples.

An efficient spectrofluorimetric method adopts doxazosin, terazosin and alfuzosin coupling with orthophthalaldehyde: Application in human plasma

A new, selective and sensitive spectrofluorimetric method was designed for the quantitation of doxazosin (DOX), terazosin (TER) and alfuzosin (ALF) in their dosage forms and human plasma. The method adopts efficient derivatization of the studied drugs with ortho-phthalaldehyde (OPA), in the presence of 2-mercaptoethanol in borate buffer (pH9.7) to generate a highly fluorescent isoindole derivatives, which can strongly enhance the fluorescence intensities of the studied drugs, allowing their sensitive determination at 430nm after excitation at 337nm. The fluorescence-concentration plots were rectilinear over the ranges (10.0-400.0) ng/mL. Detection and quantification limits were found to be (0.52-3.88) and (1.59-11.76) ng/mL, respectively. The proposed method was validated according to ICH guidelines, and successfully applied for the determination of pharmaceutical preparations of the studied drugs. Moreover, the high sensitivity of the proposed method permits its successful application to the analysis of the studied drugs in spiked human plasma with % recovery (96.12±1.34-100.66±0.57, n=3). A proposal for the reaction mechanism was presented.

Measurement of biochemical oxygen demand of the leachates

Biochemical oxygen demand (BOD) of the leachates originally from the different types of landfill sites was studied based on the data measured using the two manometric methods. The measurements of BOD using the dilution method were carried out to assess the typical physicochemical and biological characteristics of the leachates together with some other parameters. The linear regression analysis was used to predict rate constants for biochemical reactions and ultimate BOD values of the different leachates. The rate of a biochemical reaction implicated in microbial biodegradation of pollutants depends on the leachate characteristics, mass of contaminant in the leachate, and nature of the leachate. Character of leachate samples for BOD analysis of using the different methods may differ significantly during the experimental period, resulting in different BOD values. This work intends to verify effect of the different dilutions for the manometric method tests on the BOD concentrations of the leachate samples to contribute to the assessment of reaction rate and microbial consumption of oxygen.