Improved Dissolution Properties of Co-amorphous Probucol with Atorvastatin Calcium Trihydrate Prepared by Spray-Drying.

A co-amorphous model drug was prepared by the spray-drying (SD) of probucol (PC) and atorvastatin calcium trihydrate salt (ATO) as low water solubility and co-former components, respectively. The physicochemical properties of the prepared samples were characterized by powder X-ray diffraction (PXRD) analysis, thermal analysis, Fourier transform infrared spectroscopy (FTIR), and dissolution tests. Stability tests were also conducted under a stress environment of 40 °C and 75% relative humidity. The results of PXRD measurements and thermal analysis suggested that PC and ATO form a co-amorphous system by SD. Thermal analysis also indicated an endothermic peak that followed an exotherm in amorphous PC and a physical mixture (PM) of amorphous PC and ATO; however, no endothermic peak was detected in the co-amorphous system. The dissolution profiles for PC in the co-amorphous sample composed of PC and ATO were improved compared to those for raw PC crystals or the PM. Stability tests indicated that the co-amorphous material formed by PC and ATO can be stored for 35 d without crystallization, whereas amorphous PC became crystallized within a day. Therefore, co-amorphization of PC and ATO prepared by SD is considered to be a useful method to improve the solubility of PC in water.

Evaluation of Tumor Tissue Fixation Effects of Formulation Modified Mohs Pastes in Mice and Their Water-Absorbing Properties.

Mohs paste (MP) is a hospital preparation containing zinc hydrochloride and zinc oxide starch. It is a topical medication used to fixate tissues for the removal of inoperable skin tumors and the management of hemorrhage and exudates, and to prevent foul odor resulting from secondary infections. However, it has problems, such as changes in hardness and viscoelasticity with time and liquefaction by exudate. It has been reported that the modified MP with D-sorbitol (S-MP) and the modified MP using the cellulose instead of starch (C-MP) have excellent physicochemical stability and better handling than original MP (O-MP). In this study, the effect of prescription improvement of MP on the pharmacological effect was examined with reference to water absorbing property, and its tumor tissue invasion fixation depth as an indicator. In the S-MP and C-MP, the amounts of water absorption did not differ significantly from those in the O-MP. The hardness of S-MP was decreased and liquefied like O-MP after absorbing water. In contrast, C-MP retained its form even after water absorption. The subcutaneous tumors in mice treated with modified MP formulations were measured for invasion fixation depth at 6 and 24 h after application. And the tissue status was observed using computed tomography. In all MPs, invasion fixation depth increased depending on application time. S-MP and O-MP depths did not differ significantly. The invasion depths of the C-MP significantly increased compared with those in the O-MP. These results suggest that C-MP had a high tissue fixation rate.

Morphological study of efficacy of clarithromycin-loaded nanocarriers for treatment of biofilm infection disease.

In this study, we developed a drug delivery system (DDS) using polymeric nanocarriers for the treatment of biofilm infection disease. Clarithromycin (CAM)-encapsulated and chitosan (CS) modified polymeric nanoparticles (NPs) were prepared using a polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (Soluplus®) (Sol) and poly-(DL-lactide-co-glycolide), respectively. To understand the availability of the prepared NPs, we made morphological observations of the antibacterial activity derived from the NPs toward the bacterial cells within the biofilm using scanning electron microscopy and transmission electron microscopy measurements. These results revealed different antibacterial activities for the two types of drug carriers. In the case of CAM-encapsulated + CS-modified Sol micelles treatment, NPs can exert their antibacterial activity not only by the surfactant, CAM and CS effects but also by intrusion into the bacterial cells. Thereby, CAM-encapsulated + CS-modified Sol micelles had a higher antibacterial activity. The morphological information is useful to design suitable NPs for the treatment against biofilm infections.

Electron microscopy of Staphylococcus epidermidis fibril and biofilm formation using image-enhancing ionic liquid.

We established an optimized biofilm observation method using a hydrophilic ionic liquid (IL), 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]). In the present study, a biofilm was formed by Staphylococcus epidermidis. Using field emission (FE) scanning electron microscopy (SEM) and transmission electron microscopy (TEM), the colonization of assemblages formed by microbial cells was observed as a function of the cultivation time. FE-TEM analysis revealed that the fibril comprises three types of protein. In addition, the ultrastructure of each protein monomer was visualized. It was expected that the curly-structured protein plays an important role in extension during fibril formation. Compared to the conventional sample preparation method for electron microscopy, a fine structure was easily obtained by the present method using IL. This observation technique can provide valuable information to characterize the ultrastructure of the fibril and biofilm that has not been revealed till date. Furthermore, these findings of the molecular architecture of the fibril and the colonization behavior of microbial cells during biofilm formation are useful for the development of antibacterial drugs and microbial utilization.

Structural Analysis of Crystalline R(+)-α-Lipoic Acid-α-cyclodextrin Complex Based on Microscopic and Spectroscopic Studies.

R(+)-α-lipoic acid (RALA) is a naturally-occurring substance, and its protein-bound form plays significant role in the energy metabolism in the mitochondria. RALA is vulnerable to a variety of physical stimuli, including heat and UV light, which prompted us to study the stability of its complexes with cyclodextrins (CDs). In this study, we have prepared and purified a crystalline RALA-αCD complex and evaluated its properties in the solid state. The results of ¹H NMR and PXRD analyses indicated that the crystalline RALA-αCD complex is a channel type complex with a molar ratio of 2:3 (RALA:α-CD). Attenuated total reflection/Fourier transform infrared analysis of the complex showed the shift of the C=O stretching vibration of RALA due to the formation of the RALA-αCD complex. Raman spectroscopic analysis revealed the significant weakness of the S-S and C-S stretching vibrations of RALA in the RALA-αCD complex implying that the dithiolane ring of RALA is almost enclosed in glucose ring of α-CD. Extent of this effect was dependent on the direction of the excitation laser to the hexagonal morphology of the crystal. Solid-state NMR analysis allowed for the chemical shift of the C=O peak to be precisely determined. These results suggested that RALA was positioned in the α-CD cavity with its 1,2-dithiolane ring orientated perpendicular to the plane of the α-CD ring.

Improvement of the antitumor activity of poorly soluble sapacitabine (CS-682) by using Soluplus® as a surfactant.

Sapacitabine (CS-682 or CYC682; 1-[2-C-cyano-2-deoxy-ß-D-arabino-pentfuranosyl]N4-palmitoyl cytosine), a novel antitumor 2'-deoxycytidine analogue, shows a marked reduction in the water solubility because of the fatty acid side chain on the N4 group of the cytosine moiety. Poor water solubility is one of the important reasons why sapacitabine does not exert maximum antitumor activity. Therefore, we attempted to improve the water solubility of sapacitabine using a novel surfactant, Soluplus®, which consisted of a polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer. In this study, we examined whether Soluplus® increased the water solubility and an antitumor activity of sapacitabine. The cytotoxicity of Soluplus® alone was lower than that of Tween 80 and Kolliphor® D-α-tocopherylpolyethylene glycol 1000 succinate (TPGS). The water solubility and the chemosensitivity of sapacitabine against several tumor cell lines to sapacitabine markedly increased upon using Soluplus®. In addition, the potential of Soluplus® including sapacitabine in increasing the antitumor activity was compared with sapacitabine alone in vivo. Although the total dose in the experimental period was considerably lower than the effective dose of sapacitabine alone, the life span of mice treated with sapacitabine containing 40 mg/mL Soluplus® increased by 150%. If Soluplus® was used as the solubilizing agent in clinical trials of sapacitabine, a low administration dose was appeared to require, and thus side effects might be prevented.

Spectroscopic studies of R(+)-α-lipoic acid--cyclodextrin complexes.

α-Lipoic acid (ALA) has a chiral center at the C6 position, and exists as two enantiomers, R(+)-ALA (RALA) and S(-)-ALA (SALA). RALA is naturally occurring, and is a cofactor for mitochondrial enzymes, therefore playing a major role in energy metabolism. However, RALA cannot be used for pharmaceuticals or nutraceuticals because it readily polymerizes via a 1,2-dithiolane ring-opening when exposed to light or heat. So, it is highly desired to find out the method to stabilize RALA. The purpose of this study is to provide the spectroscopic information of stabilized RALA and SALA through complexation with cyclodextrins (CDs), α-CD, ß-CD and γ-CD and to examine the physical characteristics of the resultant complexes in the solid state. The RALA-CD structures were elucidated based on the micro fourier transform infrared (FT-IR) and Raman analyses. The FT-IR results showed that the C=O stretching vibration of RALA appeared at 1717 cm⁻¹ and then shifted on formation of the RALA-CD complexes. The Raman spectra showed that the S-S and C-S stretching vibrations for RALA at 511 cm⁻¹ (S-S), 631 cm⁻¹ (C-S) and 675 cm⁻¹ (C-S) drastically weakened and almost disappeared upon complexation with CDs. Several peaks indicative of O-H vibrations also shifted or changed in intensity. These results indicate that RALA and CDs form host-guest complexes by interacting with one another.

Distinguishing true from pseudo hematoma in the cervical spinal canal using postmortem computed tomography.

Spinal cord injury is difficult to detect directly on postmortem computed tomography (PMCT) and it is usually diagnosed by indirect findings such as a hematoma in the spinal canal. However, we have encountered cases where the hematoma-like high-attenuation area in the cervical spinal canal was visible on PMCT, while no hematoma was observed at autopsy; we called it a "pseudo hematoma in the cervical spinal canal (pseudo-HCSC)." In this retrospective study, we performed statistical analysis to distinguish true from pseudo-HCSC. The cervical spinal canal was dissected in 35 autopsy cases with a hematoma-like high-attenuation area (CT values 60-100 Hounsfield Unit (HU)) in the spinal canal from the first to the fourth cervical vertebrae in axial slices of PMCT images. Of these 22 had a hematoma and 13 did not (pseudo-HCSC). The location and length of the hematoma-like high-attenuation and spinal cord areas were assessed on reconstructed PMCT images, true HCSC cases had longer the posterior hematoma-like area and shorter the spinal cord area in the midline of the spinal canal (P < 0.05). Furthermore, we found that true HCSC cases were more likely to have fractures and gases on PMCT while pseudo-HCSC cases were more likely to have significant facial congestion (P < 0.05). We suggest that pseudo-HCSC on PMCT is related to congestion of the internal vertebral venous plexus. This study raises awareness about the importance of distinguishing true HCSC from pseudo-HCSC in PMCT diagnosis, and it also presents methods for differentiation between these two groups.

Quetiapine free base complexed with cyclodextrins to improve solubility for parenteral use.

Quetiapine, an antipsychotic drug used for schizophrenia treatment, is poorly water soluble, and therefore, administration of the more water-soluble quetiapine fumarate is preferred. Absorption of quetiapine through biological membranes may be improved by enhancing the solubility of the quetiapine base, the non-ionic form. In this study, the currently used salt form was converted into the free base (oily material). We employed cyclodextrins (CDs) as pharmaceutical additives to improve the solubility of the quetiapine base. The formation of quetiapine-ß-cyclodextrin (ß-CD) complexes was studied by phase solubility studies, continuous variation method, NMR spectroscopy, and powder X-ray diffraction. The formation of a poorly water-soluble complex was confirmed by the phase solubility study, and the interaction between quetiapine and ß-CD in water was confirmed by NMR spectroscopy. In addition, the effects of ß-CD derivatives (glucosyl-ß-CD, maltosyl-ß-CD, 2-hydroxypropyl-ß-CD, dimethyl-ß-CD, and trimethyl-ß-CD) on the solubility of the quetiapine base were studied. The findings indicated that the aforementioned hydrophilic ß-CD derivatives could be used as pharmaceutical additives of quetiapine for parenteral formulations as a result of the improved solubility of the quetiapine base because of inclusion complexation. Therefore, converting the currently used salt form into the free base, investigating the free base as a candidate for CD inclusion, and converting the oily material such as the free base into a powder by forming an inclusion complex that is easy to deal with is considered a worthwhile approach that may lead to novel formulations of the drug in question.

Progressive Thymic Hyperplasia With Graves' Disease: A Case Report.

We treated a 36-year-old man with thymic hyperplasia complicated with Graves' disease. Thymic hyperplasia was observed on thoracic computed tomography (CT) three months after the onset of thyrotoxicosis symptoms. One month after thiamazole initiation, he displayed drug-induced liver injury and underwent a total thyroidectomy. Seven months after surgery, we observed a dramatic reduction of thymic size associated with normalizing the soluble interleukin-2 receptor (sIL-2R) levels. The rapid development of hyperplasia after the onset of thyrotoxicosis and the restoration in thymus volume after total thyroidectomy associated with suppression of sIL-2R, in this case, suggests the complexity of the pathogenesis of thymic hyperplasia in the thyrotoxicosis.

Advanced glycation end products (AGEs), but not high glucose, inhibit the osteoblastic differentiation of mouse stromal ST2 cells through the suppression of osterix expression, and inhibit cell growth and increasing cell apoptosis.

Diabetes mellitus is known to be associated with osteoporotic fractures through a decrease in osteoblastic bone formation rather than an increase in osteoclastic bone resorption. However, its precise mechanism is unknown, and we examined whether or not high glucose or advanced glycation end products (AGEs), which play key roles in the pathogenesis and complications of diabetes, would affect the osteoblastic differentiation, growth, and apoptosis of mouse stromal ST2 cells. Ten to 200 µg/mL AGE2 or AGE3 alone dose-dependently inhibited the mineralization. AGE2 or AGE3 alone (200 µg/mL) significantly inhibited alkaline phosphatase (ALP) activities as well as the mineralization of the cells (p < 0.01). In contrast, 22 mM glucose alone or in combination with 200 µg/mL AGE2 or AGE3 did not affect these cellular phenotypes. Real-time PCR showed that AGE2 or AGE3 alone (200 µg/mL) significantly decreased mRNA expressions of osteocalcin as well as osterix on day 14 (p < 0.01). Western blot analysis showed that AGE2 or AGE3 alone (200 µg/mL) also decreased the levels of Runx2 and osterix protein expressions on days 7 and 14. AGE2 or AGE3 significantly suppressed cell growth and increased apoptotic cell death in time- and dose-dependent manners (p < 0.01). Moreover, AGE3 alone (200 µg/mL) significantly increased mRNA expression of the receptor for AGEs (RAGE) on days 2 and 3 (p < 0.01). These results suggest that AGE2 and AGE3, but not high glucose, may inhibit the osteoblastic differentiation of stromal cells by decreasing osterix expression and partly by increasing RAGE expression, as well as inhibiting cell growth and increasing cell apoptosis.

Physical stability of stealth nanobeacon using surface-enhanced Raman scattering for anti-counterfeiting and monitoring medication adherence: Deposition on various coating tablets.

Microtaggant technologies can encode individual numbers on coating tablet to authenticate pharmaceutical products and, therefore, combat the global spread of falsified medicine. In this study, a novel microtaggant, stealth nanobeacon (NB), with surface-enhanced Raman scattering (SERS) activity was applied to various coating tablets and its physical stability was evaluated. The NBs were composed of a reporter molecule (AH, adenine hydrochloride) and prepared with different sizes of gold nanoparticles (AuNPs). The NBs were directly deposited on the surface of various model coatings (e.g., hydroxypropyl cellulose, hydroxypropyl methyl cellulose, Eudragit® RS30D, ethyl cellulose). To investigate physical stability of the NB on the coating tablets, SERS spectra of the NB after friability test and acceleration test (store at 75% RH, 40 °C) were evaluated using a portable Raman spectrometer. After the friability test, there was no significant decrease in the peak intensity of the SERS signal (PH) for authentication in all samples. In the acceleration test, the SERS signals of the samples were attenuated, but sufficient SERS signal intensity (PH > 70) was maintained in the seven types of coating for authentication. These results demonstrate that the microtaggant NB has the potential to be used for a wide range of coating tablets.

Design and preparation of nanocomposite acrylate coating agents for binder-free dry coating of 100 µm-sized drug-containing particles and their coating performance.

For binder-free dry particulate coating to prepare controlled-release micron-sized particles, we designed nanocomposite coating agents with the intention to form a core-shell structure composed of two types of acrylic polymers with different glass transition temperatures (Tg) and evaluated their coating performance. A series of nanocomposite acrylic latexes synthesized by emulsion polymerization was freeze-dried after salting-out to create the powder form. An ion-exchange resin loaded with diclofenac sodium (DS, a model drug) (IER-DS) with a median diameter of approximately 100 µm was used as the core particle. Dry coating of the IER-DS with nanocomposite coating agents was carried out using a laboratory-made coating apparatus assisted with mild-intensity vibration and zirconia bead impaction. The coated particles were cured by heating at a temperature 20 °C higher than the Tg for 12 h to complete the film-forming process. It was found that the highest coating efficiency (more than 70%) and a remarkably prolonged release period of the drug (the time required for 50% release reached approximately 12 h) could be achieved when nanocomposite coating agents with a soft polymeric core (Tg = 30 °C) and a hard polymeric shell (Tg = 80 °C) were applied. In contrast, nanocomposite coating agents with a combination of a hard polymeric core and a soft polymeric shell resulted in lower coating efficiency. These results demonstrate that nanocomposite polymeric coating agents composed of a soft core and a hard shell are effective for the production of drug-loaded microparticles with a prolonged release function by a binder-free dry-coating process.

[Microtaggant Technology for Ensuring Traceability of Pharmaceutical Formulations: Potential for Anti-counterfeiting Measures, Distribution and Medication Management].

The globalization of drug trade has led to the increased production of falsified medicines. In addition, poor medication adherence increases the costs of healthcare. The need to manage medication has given rise to marketing of highly functional networked digital medicine. Therefore, a growing need has emerged to ensure the traceability of pharmaceutical products from shipment to patient distribution. Microtaggant technologies that can encode individual numbers on pharmaceutical products are expected to serve achieving this goal. Taggants are a class of materials that can be applied to an object to make it identifiable, like barcodes and holograms. Since the smaller size of microtaggant make it invisible to naked eyes, it is more difficult to reverse-engineer than conventional taggants. The U.S. Food and Drug Administration (FDA) has established guidelines for the use of microtaggants. Many studies have explored the use of various analytical technologies and materials as the microtaggants. However, the advantages and disadvantages of each method have not been established yet. In this review, recent research on the use of microtaggants for anti-counterfeiting is summarized and compared to current anti-counterfeiting technologies with spectrographic methods, distribution management systems with barcodes, and medication management systems with sensor devices. We also discuss the microtaggants implementation costs and security level.

Administration of retinoic acid to pregnant mice increases the number of fetal mouse glomeruli.

The prevalence of chronic kidney disease (CKD) is increasing worldwide, and CKD is a serious global health problem. Low glomerular number is one of the risk factors for CKD; therefore, the glomerular number is associated with the risk of CKD. Increasing the glomerular number above normal levels may reduce the risk of CKD. It has been reported that, in vitro, the addition of retinoic acid (RA) to the culture medium increases the glomerular number. However, there is no report of an increase in glomerular number above normal levels with the addition of RA in vivo. In this study, RA (20 mg/kg) was administered intraperitoneally to pregnant mice once at embryonic day (E) 10.5, E12.5, E14.5, or E16.5. The fetuses were harvested at E18.5 and fetal mouse kidneys were evaluated. Fetal kidney volume and weight were significantly increased in the E16.5 group compared to the control group. The total glomerular number in the E16.5 group was also approximately 1.46 times higher than that in the control group. In summary, we established a method to increase the glomerular number in the fetal kidney by administration of RA to pregnant mice at E16.5. These results will facilitate the investigation of whether CKD risk is reduced when the glomerular number increases above normal.

Global pattern of interkinetic nuclear migration in tracheoesophageal epithelia of the mouse embryo: Interorgan and intraorgan regional differences.

Interkinetic nuclear migration (INM) is an apicobasal (AB) polarity-based regulatory mechanism of proliferation/differentiation in epithelial stem/progenitor cells. We previously documented INM in the endoderm-derived tracheal/esophageal epithelia at embryonic day (E) 11.5 and suggested that INM is involved in the development of both organs. We here investigated interorgan (trachea vs esophagus) and intraorgan regional (ventral vs dorsal) differences in the INM mode in the tracheal and esophageal epithelia of the mouse embryo. We also analyzed convergent extension (CE) and planar cell movement (PCM) in the epithelia based on cell distribution. The pregnant C57BL/6J mice were intraperitoneally injected with 5-ethynyl-2'-deoxyuridine at E11.5 and E12.5 and were sacrificed 1, 4, 6, 8, and 12 hours later to obtain the embryos. The distribution of labeled cell nuclei along the AB axis was chronologically analyzed in the total, ventral, and dorsal sides of the epithelia. The percentage distribution of the nuclei population was represented by histogram and the chronological change was analyzed statistically using multidimensional scaling. The interorgan comparison of the INM mode during E11.5-E12.0, but not E12.5-E13.0, showed a significant difference. During E11.5-E12.0 the trachea, but not the esophagus, showed a significant difference between ventral and dorsal sides. During E12.5-E13.0 neither organ showed regional differences. CE appeared to occur in both organs during E11.5-E12.0 while PCM was unclear in both organs. These findings suggest a difference between the trachea and esophagus, and a regional difference in the trachea, not in the esophagus, in the INM mode, which may be related with the later differential organogenesis/histogenesis of these organs.

Poor Walking Speed Is Associated With Higher Segment-Specific Arterial Stiffness in Older Adult Japanese Community Dwellers: A Cross-Sectional Study.

Walking speed as one index of gait ability is an important component of physical fitness among older adults. Walking speed-arterial stiffness relationships have been studied, but whether poor walking speed is associated with higher segment-specific arterial stiffness in older adults is unclear. We thus aimed to examine the relationship between walking speed and segmental arterial stiffness among older community dwellers. This study was a cross-sectional study of 492 older Japanese community dwellers (age range, 65 to 96 years). Heart-brachial PWV (hbPWV), brachial-ankle PWV (baPWV), heart-ankle PWV (haPWV), and cardio-ankle vascular index (CAVI) were used as arterial stiffness indices. Walking speed, strength, flexibility, and cognitive function were also assessed. The participants were categorized into low (Slow), middle (Middle), and high (Fast) tertiles according to walking speed. The CAVI and baPWV were significantly lower in Fast than in Slow. Significant decreasing trends in CAVI and baPWV and a tendency toward decreasing trend in haPWV were observed from Slow to Fast, whereas hbPWV did not significantly differ among tertiles and no trend was evident. The results remained significant after normalizing CAVI and PWVs for multicollinearity of arterial stiffness indices and major confounding factors, such as age, gender, body mass index, blood pressure, cognitive function, and each physical fitness. Therefore, these findings suggest that poor walking speed is associated with higher segment-specific arterial stiffness of the central and lower limbs, but not of upper, in older adult community dwellers.

Negative Mood States Are Related to the Characteristics of Facial Expression Drawing: A Cross-Sectional Study.

An assessment of mood or emotion is important in developing mental health measures, and facial expressions are strongly related to mood or emotion. This study thus aimed to examine the relationship between levels of negative mood and characteristics of mouth parts when moods are drawn as facial expressions on a common platform. A cross-sectional study of Japanese college freshmen was conducted, and 1,068 valid responses were analyzed. The questionnaire survey consisted of participants' characteristics, the Profile of Mood States (POMS), and a sheet of facial expression drawing (FACED), and the sheet was digitized and analyzed using an image-analysis software. Based on the total POMS score as an index of negative mood, the participants were divided into four groups: low (L), normal (N), high (H), and very high (VH). Lengths of drawn lines and between both mouth corners were significantly longer, and circularity and roundness were significantly higher in the L group. With increasing levels of negative mood, significant decreasing trends were observed in these lengths. Convex downward and enclosed figures were significantly predominant in the L group, while convex upward figures were significantly predominant and a tendency toward predominance of no drawn mouths or line figures was found in the H and VH groups. Our results suggest that mood states can be significantly related to the size and figure characteristics of drawn mouths of FACED on a non-verbal common platform. That is, these findings mean that subjects with low negative mood may draw a greater and rounder mouth and figures that may be enclosed and downward convex, while subjects with a high negative mood may not draw the line, or if any, may draw the line shorter and upward convex.

Crystallographic evaluation of the conformation of quetiapine included in ß-cyclodextrin.

Single-crystal X-ray diffraction and theoretical calculations were conducted for insights into the ß-cyclodextrin (ß-CD)-quetiapine inclusion complex structure. ß-CD and quetiapine form a host-guest inclusion complex at a ratio of 2:1 in which the ß-CD molecules form head-to-head dimers with their secondary hydroxyl groups linked by multiple hydrogen bonds. Quetiapine is totally contained within the ß-CD cavity and exhibits two kinds of disorder (parts 1 and 2) in opposite directions in the ß-CD complex. To clarify the mobility of the guest molecule in the ß-CD cavity, theoretical molecular conformational calculations, crystal optimization and crystal energy calculations were conducted using CONFLEX software. The results of theoretical molecular conformation calculations showed that the mobility of quetiapine is restricted because its tricyclic structure is covered by ß-CD. The results of crystal energy calculations indicated that the conformation of disorder part 1, which has high occupancy, was more stable.

Optimization of ionic liquid-incorporated PLGA nanoparticles for treatment of biofilm infections.

Ionic liquids (ILs) containing imidazolium cations have a number of useful properties, such as high permeability to cells, high antimicrobial activity, and good biocompatibility. With the aid of ILs, transdermal delivery, solubilization of poorly soluble drugs were developed and therapeutic effects were improved. In this work, 1­butyl­3­methylimidazolium hexafluorophosphate-incorporated, chitosan-modified, submicron-sized poly(dl­lactide­co­glycolide) (PLGA) nanoparticles (NPs) were prepared using the emulsion solvent diffusion method for the treatment of biofilm infections. Prepared IL-incorporated PLGA NPs using surfactants such as Tween-80 and poloxamer-188 showed a high antibacterial activity to the bacterial cells under the biofilm. Additionally, antibacterial mechanism of IL-incorporated PLGA NPs was revealed by annular dark field scanning transmission electron microscopy combined a simple sample pretreatment method. We established a drug delivery system using IL-incorporated PLGA NPs to enhance the potential of polymeric nanocarriers for treating biofilm infections.