Ten years for PhysChem Forum-Japan (PCF-J).

The ten years of PhysChem Forum-Japan and Konstantin Tsinman's great contributions to the forum are briefly described.

The Impact of Ascidian (Halocynthia roretzi)-derived Plasmalogen on Cognitive Function in Healthy Humans: A Randomized, Double-blind, Placebo-controlled Trial.

OBJECTIVES: Plasmalogen, phospholipids with previously shown associations with dementia, has attracted attention as a substance found in some studies to improve cognitive function. The effects of ascidian-derived plasmalogens on cognitive performance improvement were assessed in a randomized, double-blind, placebo-controlled study including Japanese adult volunteers with mild forgetfulness. METHODS: Participants consumed either the active food containing ascidian-derived plasmalogen (1 mg as plasmalogen) or the placebo food for 12 weeks, and their cognitive performance was assessed by Cognitrax. Participants were randomly allocated into the intervention (ascidian-derived plasmalogen; 8 males, and 17 females; 45.6 ± 11.1 years) or the placebo (9 males, and 15 females; mean age, 46.4 ± 10.8 years) group. RESULTS: Compared to the placebo group, the intervention group showed a significant increase score in composite memory (eight weeks: 3.0 ± 16.3 points, 12 weeks: 6.7 ± 17.5 points), which was defined as the sum of verbal and visual memory scores. CONCLUSIONS: These results indicate the consumption of ascidian-derived plasmalogen maintains and enhances memory function. This study was registered at the University Hospital Medical Information Network Clinical Trial Registry (UMIN-CTR, registry no. UMIN000026297). This study did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Ultrasound radiation from a three-layer thermoacoustic transformation device.

A thermophone is a thermoacoustic transducer, which generates sound via time-varying Joule heating of an electrically conductive layer, which leads to expansion and contraction of a small pocket of air near the surface of the film. In this work, a 10-µm-thick Ag-Pd conductive film was coupled with heat-insulating and heat-releasing layers to fabricate a three-layer thermophone for generating ultrasound. The heat-insulating layer was 47 µm thick, and was made of glass. The heat-releasing layer was 594 µm thick, and was made of 94% alumina. Because of the simple sound-generation mechanism, which does not require mechanical moving parts, the Ag-Pd conductive film on the glass substrate can produce ultrasound radiation with broadband frequency characteristics, where exiting commercial electrode materials were used. We also demonstrate that the measured directivity patterns are in good agreement with theoretical predictions, assuming a rectangular diaphragm with the same size as the metallic film.

[Strategy and collaboration between medicinal chemists and pharmaceutical scientists for drug delivery systems].

In order to successfully apply drug delivery systems (DDS) to new chemical entities (NCEs), collaboration between medicinal chemists and formulation scientists is critical for efficient drug discovery. Formulation scientists have to use 'language' that medicinal chemists understand to help promote mutual understanding, and medicinal chemists and formulation scientists have to set up strategies to use suitable DDS technologies at the discovery phase of the programmes to ensure successful transfer into the development phase. In this review, strategies of solubilisation formulation for oral delivery, inhalation delivery, nasal delivery and bioconjugation are all discussed. For example, for oral drug delivery, multiple initiatives can be proposed to improve the process to select an optimal delivery option for an NCE. From a technical perspective, formulation scientists have to explain the scope and limitations of formulations as some DDS technologies might be applicable only to limited chemical spaces. Other limitations could be the administered dose and, cost, time and resources for formulation development and manufacturing. Since DDS selection is best placed as part of lead-optimisation, formulation scientists need to be involved in discovery projects at lead selection and optimisation stages. The key to success in their collaboration is to facilitate communication between these two areas of expertise at both a strategic and scientific level. Also, it would be beneficial for medicinal chemists and formulation scientists to set common goals to improve the process of collaboration and build long term partnerships to improve DDS.

Overexpression of CHOP alone and in combination with chaperones is effective in improving antibody production in mammalian cells.

Secretory capacities including folding and assembly are believed to be limiting factors in the establishment of mammalian cell lines producing high levels of recombinant therapeutic proteins. To achieve industrial success, it is also important to improve protein folding, assembly, and secretory processes in combination with increasing transcription and translation. Here, we identified the expression of CHOP/Gadd153 and GRP78, which are unfolded protein response (UPR)-related genes, correlated with recombinant antibody production in stable CHO cells. Subsequently, CHOP overexpression resulted in increasing recombinant antibody production in some mammalian cell lines, and in addition a threefold further enhancement was obtained by combining expression with UPR-related genes or ER chaperones in transient assays. Overexpression of CHOP had no effect on the biochemical characteristics of the product. These results suggest overexpression of CHOP and its combinations may be an effective method to efficiently select a single cell line with a high level of antibody production in the development of cell lines for manufacturing.

Bridging solubility between drug discovery and development.

Solubility has a crucial role in the success of a drug candidate. Compounds with low solubility not only cause problems for in vitro and in vivo assays, but also add significant burdens to drug development. Drug discovery and drug development often have different solubility screening requirements and methodologies have been developed to meet the needs of these different stages.

Development of machine learning models of ß-cyclodextrin and sulfobutylether-ß-cyclodextrin complexation free energies.

A new set of 142 experimentally determined complexation constants between sulfobutylether-ß-cyclodextrin and diverse organic guest molecules, and 78 observations reported in literature, were used for the development of the QSPR models by the two machine learning regression methods - Cubist and Random Forest. Similar models were built for ß-cyclodextrin using the 233-compound dataset available in the literature. These results demonstrate that the machine learning regression methods can successfully describe the complex formation between organic molecules and ß-cyclodextrin or sulfobutylether-ß-cyclodextrin. In particular, the root mean square errors for the test sets predictions by the best models are low, 1.9 and 2.7kJ/mol, respectively. The developed QSPR models can be used to predict the solubilizing effect of cyclodextrins and to help prioritizing experimental work in drug discovery.

Solid-state characterization of an NR2B selective N-methyl d-aspartate (NMDA) antagonist polymorphs.

(-)-6-[2-[4-(3-Fluorophenyl)-4-hydroxy-piperidin-1-yl]-1-hydroxyethyl]-3,4-dihydro-quinolin-2(1H)-one (compound A) is an NR2B selective N-methyl d-aspartate (NMDA) antagonist that has shown at least two polymorphs, forms I and II. In this report, we prepared two polymorphs, forms I and II and their crystal forms were identified and characterized by single crystal X-ray diffractometry, differential scanning calorimetry (DSC) and variable temperature powder X-ray diffractometry (VT-PXRD). The results of DSC and VT-PXRD suggested that compound A has at least three polymorphic forms: I, II and a new form III, and that forms II and III showed an enantiotropic relationship. We also performed single crystal X-ray analyses of specific conditions based on the results of VT-PXRD. The unit cell dimensions in crystallographic parameter and molecular arrangements of form I were quite different from forms II and III. Whereas, the crystal structures of forms II and III were similar with the exception of the C58-C59-C61-C62 torsion angle.

Solid form selection of zwitterionic 5-HT4 receptor agonist.

From discovery synthesis of a zwitterionic pharmaceutical compound, 4-{[4-({[(3-isopropyl-2-oxo-2,3-dihydro-1H-benzimidazol-1-yl)carbonyl]amino}methyl)piperidin-1-yl]methyl}tetrahydro-2H-pyran-4-carboxylic acid (compound A), two anhydrous ZW-I and ZW-II and two hydrate forms ZW-III and ZW-IV were identified. Although stable form ZW-I was chemically stable at 70 degrees C/75% RH for 10 days, it was transformed to hydrate form ZW-IV under ambient conditions within a few days, taking up water from atmospheric moisture. In order to select a solid form for further investigation, solid-state characterization, salt screening on 96-well plate, stable polymorph and hydrate screening and physical stability were performed. Based on the results of the salt screening, besylate, camsylate, hemi-edisylate, hemifumarate, monosuccinate salts of compound A were prepared, and their polymorphism and chemical and physical stability were evaluated. From the viewpoint of stability and manufacturability, a stable form of besylate salt (BSA-I), which had two anhydrous forms BSA-I and BSA-II and hydrate form BSA-III, was selected as a solid form. BSA-I was quite stable at high relative humidity and provided significant improvement of physical stability compared with ZW-I.

Theoretical dissolution model of poly-disperse drug particles in biorelevant media.

The purpose of the present study was to construct the theoretical dissolution model of poly-disperse drug particles in biorelevant media containing bile salt/ lecithin aggregates (micelles or vesicles). The effective diffusion coefficient in the biorelevant medium and the particle size distribution of drug particles were simultaneously factored into the Nernst-Brunner equation. The effective diffusion coefficient of a drug in the biorelevant medium was calculated to be smaller than that in the blank buffer, since the diffusion coefficient of a drug bound to the aggregates became similar to that of the aggregates. The particle size distribution of a drug powder was simulated as the sum of mono-disperse fractions covering the particle size range. To verify the modified equation, the dissolution profile of griseofulvin and danazol in a taurocholic acid/egg lecithin (4:1 mixture, taurocholic acid = 0-30 mM) system was investigated. It was clearly demonstrated that both modifications on the Nernst-Brunner equation improved the prediction accuracy. When the effect of the particle size distribution was neglected, the theoretical curve underestimated the observed value at the early phase of dissolution process. When the diffusion coefficient of a free drug was used instead of the effective diffusion coefficient, the theoretical curve overestimated the observed value. The results of the present study suggested that the effect of the particle size distribution and the effective diffusion coefficient should be taken into consideration.

Solubility and dissolution profile assessment in drug discovery.

The purposes of the review are to: a) Provide a comprehensible introduction of the-state-of-the-art sciences of solubility and dissolution, b) introduce typical technologies to assess solubility and dissolution, and c) propose the best practice strategy. The theories of solubility and dissolution required in drug discovery were reviewed especially from the view point of oral absorption. The physiological conditions in the gastrointestinal fluid in humans and animals were then briefly summarized. Technologies to assess solubility and dissolution in drug discovery were then introduced. Recently, these technologies have been improved by the laboratory automation and computational technologies. Finally, the strategies to apply these technologies for a drug discovery project were discussed.

High throughput solubility measurement with automated polarized light microscopy analysis.

As a high throughput solubility assay, the solution-precipitation method using a dimethylsulfoxide (DMSO) sample stock solution (DMSO-SP) has been widely used in drug discovery. However, the solid form of the precipitant has not been investigated. In this study, we investigated the experimental conditions of the DMSO-SP, focusing on the solid form of the precipitant. The final concentration of DMSO was 1% (v/v). The precipitant of more than a half of the model compounds was observed as crystalline by polarized light microscopy analysis. When the incubation time was 20 h and the precipitant was crystalline, the DMSO-SP solubility was similar to the solubility from a powder material (PWD). However, when the incubation time was 10 min and/or the precipitant was not crystalline, the DMSO-SP solubility was higher than the PWD solubility. These results suggested that the information regarding the solid form of the precipitant is important in interpreting the solubility data. In addition, we developed an automated birefringence diagnose system for drug discovery usage.

Crystalline form information from multiwell plate salt screening by use of Raman microscopy.

PURPOSE: The purpose of this study was to establish a useful methodology, possibly providing information on the stoichiometry of pharmaceutical drug salts obtained from salt screening by using a multiwell plate and a Raman microscope. METHODS: Tamoxifen salt screening was conducted with monobasic and polybasic acids on 96-well quartz plates with a Raman microscope. Appearance and crystalline forms of salts prepared on 96-well plates were observed by polarizing light microscope and Raman microscope, respectively. Based on the results of the salt screening, tamoxifen citrate and fumarate salts were prepared on a large scale. The salts prepared were characterized by powder X-ray diffractometry (PXRD) and ion chromatography. RESULTS: The results of the multiwell salt screening indicated that tamoxifen has a tendency toward the formation of mono salt as opposed to hemi salt with polybasic acid, and that most of tamoxifen salts gave several potential polymorphic forms. PXRD patterns of scaled-up tamoxifen citrate and fumarate salts suggested that the same crystalline form was obtained from the binary mixture regardless of molar ratios of 2:1 or 1:1 (tamoxifen/acid). The crystalline forms obtained were tamoxifen monocitrate and monofumarate salts as measured by ion chromatography. CONCLUSIONS: Salt screening on multiwell plates with a Raman microscope provided novel insight into the characteristics prediction of the stoichiometrical salts in addition to potential polymorph information. Based on the stoichiometrical information of salts, the amount of compound and time required for crystalline form selection of drug candidates would be significantly reduced.

Optimization of imidazole 5-lipoxygenase inhibitors and selection and synthesis of a development candidate.

Structural modification of imidazole 5-lipoxygenase (5-LO) inhibitors for optimizing inhibitory potency, pharmacokinetic behavior and toxicity (ocular) profile led to 4-{3-[4-(2-methyl-1H-imidazol-1-yl)phenylthio]}phenyl-3,4,5,6-tetrahydro-2H-pyran-4-carboxamide (6) with no observable ocular toxicity. The orally active and safe imidazole 5-LO inhibitor 6 was selected as a clinical candidate and advanced to clinical studies. An improved synthesis of 6 is also discussed.

5-Lipoxygenase inhibitors: convenient synthesis of 4-[3-(4-heterocyclylphenylthio)phenyl]-3,4,5,6-tetrahydro-2H-pyran-4-carboxamide analogues.

A convenient synthetic route to 4-[3-(4-heterocyclylphenylthio)phenyl]-3,4,5,6-tetrahydro-2H-pyran-4-carboxamide analogues as 5-LO inhibitors is described. This methodology enabled rapid development of structure-activity relationships (SARs) leading to improvement of pharmacological properties. Thus, new compounds with higher 5-LO inhibitory potency were discovered. The stereo-chemistry requirements of the tetrahydropyran ring are also discussed.

4-[5-Fluoro-3-[4-(2-methyl-1H-imidazol-1-yl)benzyloxy]phenyl]-3,4,5,6- tetrahydro-2H-pyran-4-carboxamide, an orally active inhibitor of 5-lipoxygenase with improved pharmacokinetic and toxicology characteristics.

Described herein are structure-activity relationships (SARs) of 4-[5-fluoro-3-[4-(2-methyl-1H-imidazol-1-yl)benzyloxy]-phenyl]-4-methoxy-3,4,5,6-tetrahydro-2H-pyran (1, CJ-12,918), an imidazole 5-lipoxygenase (5-LO) inhibitor. When 1 was tested in preclinical studies, cataract formation was observed in rats; however, this compound was metabolized extensively in vivo and showed low systemic exposure. To eliminate this side effect and enhance bioavailability, structural modification was focused on replacing the methoxy group of 1 by modulating lipophilicity (i.e., predicted log D at pH 7.4). The SARs led to the discovery of 4-[5-fluoro-3-[4-(2-methyl-1H-imidazol-1-yl)benzyloxy]phenyl]-3,4,5,6-tetrahydro-2H-pyran-4-carboxamide (10, CJ-13,454), which was less lipophilic by 1.2 log D units and showed in vivo potency (ED(50) = 4-9 mg/kg) equipotent to 1. Enhanced metabolic stability resulted in fewer in vivo metabolites, as well as improved bioavailability and a better toxicological profile. Thus, 10 was found to be a more practical lead for an orally active 5-LO inhibitor.

Novel imidazole compounds as a new series of potent, orally active inhibitors of 5-lipoxygenase.

Replacement of the dihydroquinolinone pharmacophore of Zeneca's ZD2138 by ionizable imidazolylphenyl moiety has lead to the discovery of a novel series of potent and orally active 5-lipoxygenase (5-LO) inhibitors. The synthesis and structure-activity relationship (SAR) of this series of compounds are described herein.