Yutaka Inoue

Differences in Crystallization Behavior Between Quenched and Ground Amorphous Ursodeoxycholic Acid

AbstractPurpose. To study the crystallization of ground and quenched ursodeoxycholic acid (UDCA) and to characterize their amorphous states.nMethods. Amorphous UDCA was prepared by grinding and also by rapid cooling of the melt. These samples were characterized by powder X-ray diffraction (XRD), near IR spectra and dynamic water sorption. The heat associated with crystallization was measured in an isothermal microcalorimeter at 25°C at various relative humidities (RH) (50%−100%) and, in the presence of the vapour from a mixed solvent of ethanol and water (ethanol conc. 10%−100%). The specific surface area was calculated from krypton adsorption. Contact angles were measured by using a Wilhelmy plate to calculate the surface energy of the samples.nResults. Ground and quenched samples yielded amorphous XRD patterns. Differential scanning calorimetry thermographs of the milled sample revealed that crystallization occurred at around 80°C, whereas the quenched sample did not crystallize. Exposure to humid air did not result in crystallization of either amorphous sample during the microcalorimetric experiments. In the presence of ethanol vapour, the ground sample did, but the quenched sample did not, crystallize. The amount of water sorption into the quenched sample was larger than that of the ground sample at low RH. The surface energy of the quenched material was different to that of the ground. Peak shifts were observed in the NIR spectra at around 1450, 2100 nm, allowing differentiation between the ground and quenched samples.nConclusions. It can be concluded that different molecular states of amorphous UDCA were obtained depending on the preparation method. The crystallisation of amorphous UDCA was related to the molecular state of disorder.

Nitrite reduces ischemia/reperfusion-induced muscle damage and improves survival rates in rat crush injury model.

BACKGROUND Nitrite is an intrinsic signaling molecule with potential therapeutic implications in mammalian ischemia/reperfusion (I/R) injury of the heart, liver, and kidney. Although limb muscle compression and subsequent reperfusion are the causative factors in developing crush syndrome (CS), there has been no report evaluating the therapeutic effects of nitrite on CS. We therefore tested whether nitrite could be a therapeutic agent for the treatment of CS. METHODS To create a CS model, anesthetized rats were subjected to bilateral hind limb compression with rubber tourniquets for 5 hours, followed by reperfusion for 0 hour to 6 hours while monitoring blood pressure. Saline for the CS group or sodium nitrite (NaNO2-100, 200, and 500 &mgr;mol/kg) for the nitrite-treated CS groups was intravenously administered immediately before reperfusion. Blood and tissue samples were collected for biochemical analysis. RESULTS Tissue nitrite levels in injured muscles were significantly reduced in the CS group compared with the sham group during I/R injury. Nitrite administration to CS rats restored nitric oxide bioavailability by enhancing nitrite levels of the muscle, resulting in a reduction of rhabdomyolysis markers such as potassium, lactate dehydrogenase, and creatine phosphokinase. Nitrite treatment also reduced plasma levels of interleukin-6 and myeloperoxidase activities in muscle and lung tissues, finally resulting in a dose-dependent improvement of survival rate from 24% (CS group) to 36% (NaNO2-100 group) and 64% (NaNO2-200 and 500 groups). CONCLUSION These results indicate that nitrite reduces I/R-induced muscle damage through its cytoprotective action and contributes to improved survival rate in a rat CS model.

A comparison of the physicochemical properties and a sensory test of Acyclovir creams

In external medicine, types and ratios of additives are not necessarily the same for well-known brand-name drugs and generic drugs. This study sought to compare the physicochemical properties and sensory test results of a brand-name Acyclovir (ACV) cream and two generic ACV creams. Near-infrared (NIR) spectroscopy revealed changes in absorption spectra attributed to differences in the oil and water content of the 3 creams. In addition, ACV-B and ACV-C had similar NIR absorption spectra. Microscopic examination revealed crystallization in each of the creams and droplets in ACV-C. Powder X-ray diffraction measurement revealed diffraction peaks due to ACV for ACV-A and ACV-B. Assessment of viscoelasticity indicated that stress of subjection to 35 °C caused no changes in the viscoelasticity of ACV-B and ACV-C in comparison to stress of subjection to 25 °C but it did cause the viscoelasticity of ACV-A to decrease. ACV-A had a greater tolerance to stress and a higher viscosity, tan δ, and yield value than the other 2 creams. Results of a sensory test revealed significant differences in adhesiveness, spreadability, and feel for ACV-A in comparison to ACV-B and ACV-C. Thus, differences in the viscosity and elasticity of the creams due to differences in types and ratios of additives were noted. These differences are surmised to be differences in physical properties. In addition, results suggested that viscoelasticity and spreadability in the sensory test reflected differences in physical properties.

Ascorbyl dipalmitate/PEG-lipid nanoparticles as a novel carrier for hydrophobic drugs.

L-ascorbyl 2,6-dipalmitate (ASC-DP), a fatty ester derivative of ascorbic acid, is poorly soluble in water and does not spontaneously form micelles or liposomal structures in water. In this study, we attempted to prepare an ASC-DP/surfactant nano-sized complex as a carrier for hydrophobic drugs. Samples were prepared by hydrating a solvent-evaporated film of ASC-DP/surfactant at a molar ratio of 1:1. Among the surfactants tested, distearoylphosphatidylethanolamine-polyethylene glycol 2000 (DSPE-PEG) was found to form stable nanoparticles with ASC-DP (average particle size: ca. 67 nm). Several hydrophobic drugs were incorporated in the ASC-DP/DSPE-PEG nanoparticles. Stability, toxicity, and blood residence of the drug-containing ASC-DP/DSPE-PEG nanoparticles were evaluated using amphotericin B (AmB) as the model drug. By intravenously administering mice with the formulations, we determined the minimum lethal dose of Fungizone, a formulation of AmB solubilized with sodium deoxycholate, was 3.0 mg/kg, while that of AmB/ASC-DP/DSPE-PEG nanoparticles was 10.0 mg/kg. When 2.0 mg/kg, Fungizone was administered, the mice showed higher renal and hepatic toxicities. Intravenously administered AmB/ASC-DP/DSPE-PEG nanoparticles demonstrated higher concentration in plasma than Fungizone. Thus, the ASC-DP/DSPE-PEG nanoparticle system appears to be a promising delivery system for hydrophobic drugs.

Acute lethal crush-injured rats can be successfully rescued by a single injection of high-dose dexamethasone through a pathway involving PI3K-Akt-eNOS signaling.

BACKGROUND Crush syndrome (CS) is characterized by ischemia/reperfusion–induced rhabdomyolysis and the subsequent onset of systemic inflammation. CS is associated with a high mortality, even when patients are treated with conventional therapy. We hypothesized that treatment of lethal CS rat model with dexamethasone (DEX) have therapeutic effects on the laboratory findings and clinical course and outcome. METHODS To create a CS model, anesthetized rats were subjected to bilateral hind limb compression with rubber tourniquets for 5 hours and randomly divided into three groups as follows: saline-treated CS group, CS groups treated with low (0.1 mg/kg) and high doses (5.0 mg/kg) of DEX. Saline for the CS group or DEX for the DEX-treated CS groups was intravenously administered immediately before reperfusion. Under continuous monitoring and recording of arterial blood pressures, blood and tissue samples were collected for histologic and biochemical analysis at designated period before and after reperfusion. RESULTS Ischemic compression of rat hind limbs reduced the nitrite content in the crushed muscle, and the subsequent reperfusion induced reactive oxygen species–mediated circulatory collapse and systemic inflammation, finally resulting in a mortality rate of 76% by 48 hours after reperfusion. A single injection of high-dose DEX immediately before reperfusion activated endothelial nitric oxide synthase (eNOS) by sequential phosphorylation through the nongenomic phosphoinositide 3-kinase (PI3K)–Akt–eNOS signaling pathway. DEX also exhibited anti-inflammatory effects by modulating proinflammatory and anti-inflammatory mediators, consequently suppressing myeloperoxidase activities and subsequent systemic inflammation, showing a complete recovery of the rats from lethal CS. CONCLUSION These results indicate that high-dose DEX reduces systemic inflammation and contributes to the improved survival rate in a rat CS model.

A comparison of pharmacists' role functions across various nations: The importance of screening.

In recent years, several developed countries reported on new multidisciplinary roles of pharmacists and pharmacy assistants, especially considering the formers expanding functions. This paper examines differences in pharmacists and pharmacy assistants professional roles and the dispensing system in Japan with those in the United Kingdom, Malaysia, and the Philippines. A review of relevant literature was supplemented by interviews of dispensary staff at hospitals and community pharmacies in Malaysia and the Philippines. The UK, Philippines, and Malaysia had dispensing assistants who performed dispensing roles, while Japan did not. Although pharmacy assistants occasionally performed screening and dispensing inspections due to the lack of pharmacists, it is necessary for pharmacists participating in risk management to ensure formula optimization and monitoring. Pharmacists contribution to medical care involves ensuring safety in drug therapy and overall medical services. Screening is the most fundamental and important function performed exclusively by pharmacists, thereby establishing their status within the medical system.

Effect of γ-cyclodextrin derivative complexation on the physicochemical properties and antimicrobial activity of hinokitiol

The aim of this study was to evaluate the physicochemical properties of solid dispersion on mixtures of hinokitiol (HT) and γ-cyclodextrin (γ-CD) and of HT and (2-hydroxypropyl)-γ-cyclodextrin (HP-γ-CD). Differential scanning calorimetry revealed that coground HT/γ-CD at a molar ratio of 1:1 and HT and HP-γ-CD at molar ratios of 1:1 and 1:2 lacked an endothermic peak due to melting of HT crystals. Powder x-ray diffraction revealed that HT crystal showed a halo pattern respectively, by mixing and grinding of the CDs and HT. Thus, coground HT/γ-CD and HT/HP-γ-CD at a molar ratio of 1:1 had molecular interaction. Assessment of dissolution revealed that ground mixtures had improved dissolution of HT compared to HT crystals, ground HT alone, and physical mixtures containing HT. 1H-1H NOESY NMR suggested that the 7-membered ring and isopropyl group of HT were located within the cavity of γ-CD and HP-γ-CD. The antimicrobial tests indicated that ground mixtures exhibited a minimum inhibitory concentration (MIC) of 20xa0μg/mL against Bacillus subtilis, 40xa0μg/mL against Staphylococcus aureus, and 20xa0μg/mL against Escherichia coli. GMs were found to have 4 times more antimicrobial activity than HT crystals. Ground mixtures also exhibited MIC of 160xa0μg/mL against Pseudomonas aeruginosa and they were found to 2 times more antimicrobial activity than HT crystals. Improvement in antimicrobial activity with the formation of inclusion complexes is presumably due to increase the solubility of HT as a result of the formation of HT/CD inclusion complexes.

Low-Dose Sodium Nitrite Fluid Resuscitation Prevents Lethality From Crush Syndrome by Improving Nitric Oxide Consumption and Preventing Myoglobin Cytotoxicity in Kidney in A Rat Model

Objective: Crush syndrome (CS) is a serious medical condition characterized by muscle cell damage resulting from pressure. CS has a high mortality, even when patients receive fluid therapy. We examined whether administration of NaNO2-containing fluid can improve survival in a rat model of CS. Design: The CS model was generated by subjecting anesthetized rats to bilateral hind limb compression with a rubber tourniquet for 5u200ah. Rats were then randomly divided into six groups: sham; CS with no treatment; CS with normal saline treatment; CS with normal saline + 25u200amEq/L bicarbonate treatment; and CS with normal saline + 200 or 500u200a&mgr;mol/kg NaNO2. Measurements and Main Results: Blood and tissue samples were collected for histological and biochemical analyses at predetermined time points before and after reperfusion. Ischemic compression of rat hind limbs reduced nitrite content in the crushed muscle, and subsequent reperfusion resulted in reactive oxygen species-induced circulatory dysfunction and systemic inflammation. Rats treated with 200u200a&mgr;mol/kg NaNO2 showed increased nitric oxide (NO) levels, blood circulation, and neoangiogenesis, decreased generation of reactive oxygen species, and suppression of the inflammatory response, leading to complete recovery. Conclusions: Treatment with 200u200a&mgr;mol/kg NaNO2 prevents muscle damage induced by ischemia reperfusion via the protective effects of NO and suppression of systemic inflammation, thereby increasing survival rates in CS.

Examination of intermolecular interaction as a result of cogrinding actarit and β-cyclodextrin

In this study, investigations were performed in regard to the possibility of complexation of actarit (ACT) with β-cyclodextrin (β-CD) for improving the solubility and dissolution rate. Complexes of β-CD and ACT (ACT/β-CD molar ratioxa0=xa01/1) were prepared using the cogrinding method. Formation of an ACT/β-CD inclusion complex by cogrinding was confirmed using powder X-ray diffraction measurement. The powder X-ray diffraction of the ground mixture (ACT/β-CDxa0=xa01/1) showed a halo pattern. The diffraction pattern of the ground mixture after storage at RH 82xa0%, 40xa0°C exhibited new diffraction peaks at 2θxa0=xa011.6º and 17.8º, and differed from those of ACT and β-CD crystals. In vitro studies showed that the solubility and dissolution rate of ACT were significantly improved by complexation with β-CD with respect to the drug alone. In 1H-NMR measurement, changes in chemical shift (1H) suggested that the drug phenyl moiety was included in the cavities of β-CD mainly by hydrophobic interaction, and that the primary hydroxy side of β-CD was tightly associated with each drug. The results show clear evidence of intermolecular interaction between β-CD and ACT.

Astragaloside-IV prevents acute kidney injury and inflammation by normalizing muscular mitochondrial function associated with a nitric oxide protective mechanism in crush syndrome rats

BackgroundCrush syndrome (CS) is a serious medical condition characterized by muscle cell damage resulting from decompression after compression (i.e., ischemia/reperfusion injury). A large number of CS patients develop cardiac failure, kidney dysfunction, and systemic inflammation, even when fluid therapy is administered. We evaluated whether the administration of astragaloside-IV (AS)-containing fluid improved survival by preventing kidney and muscular mitochondrial dysfunction in a rat model of CS.ResultsThe CS model was generated by subjecting anesthetized rats to bilateral hind limb compression with a rubber tourniquet for 5xa0h. Rats were then randomly divided into four groups: (1) sham; (2) CS with no treatment; (3) CS with normal saline treatment; and (4) CS with normal salinexa0+xa010xa0mg/kg AS. AS-containing fluid improved kidney function by improving shock and metabolic acidosis in CS rats. In addition, there was a reduction in oxidative damage. The attenuation of hyperkalemia was significantly related to improving muscle injury via preventing mitochondrial dysfunction. Moreover, this mitochondria protection mechanism was related to the nitric oxide (NO) generated by activation of endothelial nitric oxide synthase, which provided an anti-oxidative and anti-inflammatory effect.ConclusionsTreatment with AS-containing fluid led to a dramatic improvement in survival following CS because of direct and indirect anti-oxidative effects in the kidney, and improvements in mitochondrial dysfunction and inflammation owing to AS acting as an NO donor in injured muscle.