HPLC determination of Escitalopram in tablet dosage forms

Purpose: A simple, specific, precise, and accurate reversed phase liquid chromatographic (RP-LC) method has been developed for the determination of Escitalopram in tablet dosage form. Methods: The chromatographic separation was achieved on a LiChrosorb C18, 250 mm x 4.6 mm, 5 μm column at a detector wavelength of 270 nm and a flow rate of 1.0 ml/min. The mobile phase was composed of methanol, acetonitrile (70:30 v/v). The retention time of Escitalopram was 5.49 min. The method was validated for the parameters like specificity, linearity, precision, accuracy, limit of quantitation and limit of detection. Results: The method was found to be specific as no other peaks of impurities and excipients were observed. The square of correlation coefficient (R2) was 0.9999 while relative standard deviations were found to be <2.0%. Conclusion: The proposed RP-LC method can be applied for the routine analysis of commercially available formulations of Escitalopram.

Design, construction and operation of the ProtoDUNE-SP Liquid Argon TPC

The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber (LArTPC) that was constructed and operated in the CERN North Area at the end of the H4 beamline. This detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment (DUNE), which will be constructed at the Sandford Underground Research Facility (SURF) in Lead, South Dakota, U.S.A. The ProtoDUNE-SP detector incorporates full-size components as designed for DUNE and has an active volume of 7 × 6 × 7.2 m3. The H4 beam delivers incident particles with well-measured momenta and high-purity particle identification. ProtoDUNE-SP's successful operation between 2018 and 2020 demonstrates the effectiveness of the single-phase far detector design. This paper describes the design, construction, assembly and operation of the detector components.

Polymer Functionalized Nanoparticles in Blue Phase LC: Effect of Particle Shape

Ethylene oxide oligomers and polymers, free and tethered to gold nanoparticles, were dispersed in blue phase liquid crystals (BPLC). Gold nanospheres (AuNPs) and nanorods (AuNRs) were functionalized with thiolated ethylene oxide ligands with molecular weights ranging from 200 to 5000 g/mol. The BPLC mixture (ΔTBP ~6 °C) was based on the mesogenic acid heterodimers, n-hexylbenzoic acid (6BA) and n-trans-butylcyclohexylcarboxylic acid (4-BCHA) with the chiral dopant (R)-2-octyl 4-[4-(hexyloxy)benzoyloxy]benzoate. The lowest molecular weight oligomer lowered and widened the BP range but adding AuNPs functionalized with the same ligand had little effect. Higher concentrations or molecular weights of the ligands, free or tethered to the AuNPs, completely destabilized the BP. Mini-AuNRs functionalized with the same ligands lowered and widened the BP temperature range with longer mini-AuNRs having a larger effect. In contrast to the AuNPs, the mini-AuNRs with the higher molecular weight ligands widened rather than destabilized the BP, though the lowest MW ligand yielded the largest BP range, (ΔTBP > 13 °C). The different effects on the BP may be due to the AuNPs accumulating at singular defect sites whereas the mini-AuNRs, with diameters smaller than that of the disclination lines, can more efficiently fill in the BP defects.