Publications by authors named "Lee Tu"

The surprisingly stable irinotecan hydrochloride trihydrate injection concentrate having a supersaturated concentration of 20 mg/mL at 25 °C was due to the frustration of 150-nm sized liquid-like nanosized clusters formed by the aggregation of dimers of 1.5 nm in an aqueous phase, evidenced by the non-linearity of van't Hoff plot and dynamic light scattering measurement. The adoption of this stable supersaturated solution at 20 mg/mL by manufacturers as the commercial concentration was beneficial due to the less volume being involved throughout the manufacturing, handling, storage and transportation of the commercial product, while also enabling a versatile on-site concentration adjustment by dilution prior to intravenous administration.

View Article and Find Full Text PDF

Deployable tubular structures, designed for functional expansion, serve a wide range of applications, from flexible pipes to stiff structural elements. These structures, which transform from compact states, are crucial for creating adaptive solutions across engineering and scientific fields. A significant barrier to advancing their performance is balancing expandability with stiffness.

View Article and Find Full Text PDF

Organic solvent-free process or green chemistry is needed for manufacturing pharmaceutical salts to avoid various environmental, safety, and manufacturing cost issues involved. In this study, a cinnarizine (CNZ) salt with malic acid at a 1:1 molar ratio was successfully prepared by twin screw extrusion (TSE) with water assistance. The feasibility of salt formation was first evaluated by screening several carboxylic acids by neat grinding (NG) and liquid-assisted grinding (LAG) using a mortar and pestle, which indicated that malic acid and succinic acid could form salts with CNZ.

View Article and Find Full Text PDF

This study describes the preparation, characterization, and influence of the enantiopure vs. racemic coformer on the physico-chemical properties of a pharmaceutical cocrystal. For that purpose, two new 1:1 cocrystals, namely lidocaine:dl-menthol and lidocaine:d-menthol, were prepared.

View Article and Find Full Text PDF

Goldberg polyhedra have been widely studied across multiple fields, as their distinctive pattern can lead to many useful applications. Their topology can be determined using Goldberg's method through generating topologically equivalent structures, named cages. However, the geometry of Goldberg polyhedra remains underexplored.

View Article and Find Full Text PDF

Form II paracetamol has captured the interest of researchers due to its improved compressibility. However, its low stability has made it difficult to be produced on a large scale with good reproducibility. In the present study, the selective polymorphic formation of paracetamol was carried out by cooling crystallization with four types of additives: adipic acid, fumaric acid, oxalic acid, and succinic acid.

View Article and Find Full Text PDF

A novel hydrate form of sodium dodecyl sulfate (SDS) was firstly discovered through a hydrate screening with the use of organic solvents, while SDS is generally prepared solely in aqueous media. Surprisingly, a novel SDS hydrate form with needle-shaped crystals produced by adding acetonitrile to a 20 wt % SDS aqueous solution at a ratio of 3:1 (v/v) and further cooling to around 5 °C could be found with a trace amount in one of the two purchased SDS products that we examined. After comprehensive solid-state characterizations by powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), Raman spectroscopy, dynamic vapor sorption (DVS), and elemental analysis (EA), it is also successfully made directly from the synthesis of SDS through esterification and saponification.

View Article and Find Full Text PDF

The COVID-19 pandemic has created enormous global demand for personal protective equipment (PPE). Face shields are an important component of PPE for front-line workers in the context of the COVID-19 pandemic, providing protection of the face from splashes and sprays of virus-containing fluids. Existing face shield designs and manufacturing procedures may not allow for production and distribution of face shields in sufficient volume to meet global demand, particularly in Low and Middle-Income countries.

View Article and Find Full Text PDF

The concept of drug recycle by recovering active pharmaceutical ingredients (APIs) from unused tablets and capsules was demonstrated using acetaminophen, tetracycline HCl, and (,)-(±)-ibuprofen as case examples. The recovery process comprised three core unit operations: solid-liquid extraction, filtration, and crystallization. Recovery yields of 58.

View Article and Find Full Text PDF

Sodium dodecyl sulfate (SDS)·1/8 hydrate (NaCHSO·1/8HO) crystals were successfully produced by evaporation, antisolvent addition, cooling crystallization, and isothermal aging in a common stirred tank. A clear 33.3 wt % SDS aqueous solution was concentrated by evaporation to a 60 wt % coagel consisting of numerous SDS hydrates and water.

View Article and Find Full Text PDF

Salts are generally prepared by acid-base reaction in relatively large volumes of organic solvents, followed by crystallization. In this study, the potential for preparing a pharmaceutical salt between haloperidol and maleic acid by a novel solvent-free method using a twin-screw melt extruder was investigated. The pH-solubility relationship between haloperidol and maleic acid in aqueous medium was first determined, which demonstrated that 1:1 salt formation between them was feasible (pH 4.

View Article and Find Full Text PDF

The adsorption of phenylaniline (Phe) enantiomers on (+)-polyaniline (PAN)-chelated [In(OH)(bdc)]n microcrystals was carefully designed and studied by using the Job titration, circular dichroism, X-ray photoelectron spectroscopy, and photoluminescence to mimic heterotrimeric guanine nucleotide-binding protein (G protein)-coupled receptors in selective, but not specific, ligand binding with chiral recognition and signal transduction. Six essential working principles across different length scales are unraveled: 1) a chiral (+)-PAN (host), 2) specific sites for Phe-(+)/PAN (guest-host) binding, 3) a conformational change of (+)-PAN after binding with Phe enantiomers, 4) different degrees of packing for (+)-PAN, 5) interactions between (+)-PAN and the underlying signal-generating framework (i.e.

View Article and Find Full Text PDF

To pave the way for technology transfer and scale up of the spherical agglomeration (SA) process for dimethyl fumarate, effects of the US, European and Kawashima type baffles and 0.5, 2.0 and 10 L-sized common stirred tank were studied.

View Article and Find Full Text PDF

This study reports the prevalence of duck hepatitis A virus (DHAV) types 1 and 3 on Korean duck farms. By RT-nested PCR assays specific for DHAV-1 or DHAV-3, DHAV-1 was detected in 9 of 157 liver samples (5.7 %) from 2 of 30 farms (6.

View Article and Find Full Text PDF

In summer, wastewater treatment plant total phosphorus (TP) removal efficiency is low in South Korea. The reason is because of high temperatures or significant fluctuation of inflow characteristics caused by frequent rainfall. Hence, this study tried to raise TP removal efficiency by injecting fixed external carbon sources in real sewage.

View Article and Find Full Text PDF

The emergence of drug resistant variants of the influenza virus has led to a need to identify novel and effective antiviral agents. As an alternative to synthetic drugs, the consolidation of empirical knowledge with ethnopharmacological evidence of medicinal plants offers a novel platform for the development of antiviral drugs. The aim of this study was to identify plant extracts with proven activity against the influenza virus.

View Article and Find Full Text PDF

This study fabricates the optically active uniform SiGe/Si multiple quantum well (MQW) nanorod and nanodot arrays from the Si0.4Ge0.6/Si MQWs using nanosphere lithography (NSL) combined with the reactive ion etching (RIE) process.

View Article and Find Full Text PDF

All experimental procedures discussed could be treated as a screening tool for probing the existence of molecular association among the chiral molecules and the solvent system. The molecular association phases of a racemic conglomerate solution (CS) and a racemic compound solution (RCS), and the templating effect of aspartic acid solid surface were observed to minimize the chance of redissolving racemic conglomerate and racemic compound aspartic acid in water and reforming an RCS in crossovers experiments. Only 1 %wt% of l-aspartic acid was adequate enough to induce a transformation from a racemic compound aspartic acid to a racemic conglomerate aspartic acid.

View Article and Find Full Text PDF

Culicoides biting midges were collected on three cattle farms weekly using light traps overnight from May to October between 2010 and 2011 in the southern part of Korea. The seasonal and geographical abundance of Culicodes spp. were measured.

View Article and Find Full Text PDF

The taste sensing capabilities of a "biomimetic tongue" based on the photoluminescence (PL) responses of metal-organic frameworks (MOFs), [In(OH)(bdc)]n (bdc=1,4-benzenedicarboxylate), [Tb(btc)]n (MOF-76, btc=benzene-1,3,5-tricarboxylate), and [Ca3(btc)2(DMF)2(H2O)2]·3H2O are proven on aqueous solutions of five basic tastants: sucrose (sweet), caffeine (bitter), citric acid (sour), sodium chloride (salty) and monosodium glutamate (umami). For [In(OH)(bdc)]n, the tastant interacts stereochemically with poly(acrylic acid) (PAA) and alters its conformations. The frequency and magnitude of chelation between COO(-) pendant groups of PAA and In(3+) nodes of [In(OH)(bdc)]n framework influence the corresponding PL reponses.

View Article and Find Full Text PDF

After the initial discovery of antiproliferative and apoptosis-inducing properties of a camptothecin-inspired pentacycle based on a 1H-indeno[2',1':5,6]dihydropyrido[2,3-d]pyrimidine scaffold, a library of its analogues as well as their oxidized planar counterparts were prepared utilizing a practical multicomponent synthetic protocol. The synthesized compounds exhibited submicromolar to low micromolar antiproliferative potencies toward a panel of human cancer cell lines. Biochemical experiments are consistent with the dihydropyridine library members undergoing intracellular oxidation to the corresponding planar pyridines, which then inhibit topoisomerase II activity, leading to inhibition of proliferation and cell death.

View Article and Find Full Text PDF

The aim of this paper is to design initial salt screening procedures for manufacturing ibuprofen. Salt forms of a pharmaceutical acid racemic (R,S)-(+/-)-ibuprofen and their "developable" synthetic routes were ferreted out simultaneously through the screening of seven bases of sodium hydroxide, potassium hydroxide, L-arginine, L-histidine, L-lysine, diethanolamine, and tris(hydroxymethyl)aminomethane (THAM), and the match with the use of nine organic solvents of methanol, dimethyl sulfoxide, ethanol, N, N-dimethylformamide, acetonitrile, isopropyl alcohol, 1,4-dioxane, acetone, and tetrahydrofuran mainly in the presence of water in 20 mL scintillation vials. Racemic (R,S)-(+/-)-sodium ibuprofen dihydrate, a well-known ibuprofen salt and the newly discovered racemic (R,S)-(+/-)-THAM ibuprofen, appeared as white-squared powders with a molecular weight of 327.

View Article and Find Full Text PDF

The purpose of this article is to promote two simple and scalable methods to accelerate the formulation development of formulated granules using acetaminophen as a model system. In method I, formulated granules made from the batch of small particle-sized acetaminophen (1) by ball milling the batch of large particle-sized acetaminophen (2), and the mixture of the two batches at equal weights (mix) gave the dissolution rate constants (k) of k(1) = 0.43 +/- 0.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_sessionrm8j4qpk6jc7jbi33inj0au85gq5e9sn): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once