Tuning the Phytoglycogen Size and Aggregate Structure with Solvent Quality: Influence of Water-Ethanol Mixtures Revealed by X-ray and Light Scattering Techniques.

Phytoglycogen (PG) is a hyperbranched polysaccharide with promising properties for biomedical and pharmaceutical applications. Herein, we explore the size and structure of sweet corn PG nanoparticles and their aggregation in water-ethanol mixtures up to the ethanol mole fraction xEtOH = 0.364 in dilute concentrations using small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS) measurements. Between 0 ≤ xEtOH ≤ 0.129, the conformation of PG contracts gradually decreasing up to ca. 80% in hydrodynamic volume, when measured shortly after ethanol addition. For equilibrated PG dispersions, SAXS suggests a lower PG volume decrease between 19 and 67% at the corresponding xEtOH range; however, the inflection point of the DLS volume contraction coincides with the onset of reduced colloidal stability observed with SAXS. Up to xEtOH = 0.201, the water-ethanol mixtures yield labile fractal and globular aggregates, as evidenced by their partial breakup under mild ultrasonic treatment, demonstrated by the decrease in their hydrodynamic size. Between 0.235 ≤ xEtOH ≤ 0.364, PG nanoparticles form larger, more cohesive globular aggregates that are less affected by ultrasonic shear forces.

Preparation and Spectroscopic Characterization of Inclusion Complexes of 3D Ball-Milled Rifampicin with ß-cyclodextrin and γ-cyclodextrin : 3D Ball-Milled Rifampicin with ß-cyclodextrin and γ-cyclodextrin.

Rifampicin (RFP) solutions, intended to reduce incidence of prosthetic graft infection, were prepared as three-dimensional ground mixtures (3DGMs) using ß-cyclodextrin (ßCD) and γ-cyclodextrin (γCD) and characterized for their spectroscopic properties and solubility. Phase solubility diagrams revealed that 3DGMs (RFP/ßCD and RFP/γCD) produced a complex at 1:1 molar ratio. Pulsed field gradient nuclear magnetic resonance experiments indicated that the diffusion coefficients for RFP/ßCD and RFP/γCD were similar to the respective diffusion coefficients for ßCD and γCD. Rotating-frame Overhauser effect spectroscopy NMR spectra revealed the existence of a new exchanger peak for RFP/γCD, suggesting an intermolecular interaction different from that of RFP/ßCD. Differential scanning calorimetry confirmed the presence of endothermic peak at 191 °C indicating the manifestation of RFP in the inclusion complex. Interestingly, molecular interactions from the complexes, RFP/ßCD and RFP/γCD, revealed different patterns of inclusion in the 3DGMs. In RFP/ßCD, nuclear Overhauser effect spectroscopy NMR spectra indicated cross peaks for the protons of the methyl group of RFP and the protons (H-5 and H-6) in the ßCD cavity. The methyl group of RFP interacted with the narrow rim of ßCD. With RFP/γCD, cross peaks were due to the protons of the methyl group of RFP and the protons of the cavity of γCD suggesting multiple inclusion patterns. The observed multiple cross peaks affirm the inclusion of RFP into the CD cavity which enhanced its solubility by 1.6-2.0-fold when prepared as 3DGMs as RFP/ßCD and RFP/γCD, respectively.

Inclusion Complexes of Daidzein with Cyclodextrin-Based Metal-Organic Framework-1 Enhance Its Solubility and Antioxidant Capacity.

Daidzein, an aglycone-type isoflavone, is useful in the prevention of atherosclerotic cardiovascular diseases. However, the solubility of daidzein remains relatively low even with pharmaceutical interventions (e.g., γ-cyclodextrin inclusion complex). In the present study, daidzein-cyclodextrin-metal organic framework solid dispersion complexes were prepared by the solvent evaporation method. The physicochemical properties of the complex and its effect on the solubility of daidzein were evaluated. The enhancement effect of a cyclodextrin-metal organic framework on the antioxidant properties of daidzein was verified using a diphenyl-picrylhydrazyl radical scavenging test. Powder X-ray diffraction results showed that the characteristic diffraction peaks of daidzein and cyclodextrin-metal organic framework disappeared and new peaks (2θ = 7.1°, 16.5°) were observed. FT-IR measurements showed that the peak derived from the carbonyl group of daidzein shifted to the lower wavenumber. NOESY 1H-1H NMR showed cross peaks at the proton on the resorcinol side of daidzein and the proton (H-5, H-6) in a cyclodextrin-metal organic framework. Dissolution rate of daidzein at 5 min in distilled water was 0.06% for daidzein alone while the daidzein inclusion complex was about 100%. When fasted state simulated intestinal fluid was used, the dissolution rate of the daidzein complex was about 71% compared with that of daidzein alone (~ 3.0%) at 5 min. The daidzein inclusion complex improved the antioxidant capacity to ~ 1.3 times (17.8 µg/mL) compared to the IC50 of daidzein alone (22.9 µg/mL). Preparations of cyclodextrin-metal organic framework inclusion complexes will be a platform in developing pharmaceutical formulations to enhance the bioavailability and activity of drugs.

Preparation and characterization of triamterene complex with ascorbic acid derivatives.

The purpose of this study was to prepare solid dispersions of triamterene (TRT) with ascorbic acid (AA) or ascorbic acid 2 glucoside (AA2G) and to evaluate their physical properties. Solid dispersions were prepared by dissolving each sample in an organic solvent and evaporation (EVP). Powder X-ray diffraction (PXRD) revealed a halo pattern for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT = 1/1). In differential scanning calorimetry (DSC), endothermic peaks due to the melting of TRT and AA disappeared for EVP1 (AA/TRT = 1/1), and the melting peaks of TRT and AA2G disappeared for EVP2 (AA2G/TRT = 1/1). Fourier transform infrared (FT-IR) spectroscopy revealed broadened peaks for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT = 1/1) due to the hydroxyl groups (-OH) of AA and the amino groups (-NH2) of TRT and also revealed a peak shift due to the pteridine skeleton (C = N) of TRT. In near-infrared absorption (NIR) spectroscopy, peaks due to the hydroxyl groups (-OH) of AA and AA2G were found for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT = 1/1), respectively. A peak due to the amino groups (-NH2) was evident. This suggested the formation of an evaporation, in which TRT interacted with AA or AA2G. In the dissolution test, the dissolved fraction of TRT alone after 3 min was 30%, whereas the fractions were enhanced to approximately 90% for EVP1 (AA/TRT = 1/1) and EVP2 (AA2G/TRT= 1/1). Results confirmed that dissolution properties were improved as a result of complex formation. The above findings indicated improvement the dissolution properties of TRT.

Photochemically stabilized formulation of dacarbazine with reduced production of algogenic photodegradants.

The present study aimed to develop a photochemically stabilized formulation of dacarbazine [5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide; DTIC] for reducing the production of algogenic photodegradant (5-diazoimidazole-4-carboxamide; Diazo-IC). Photochemical properties of DTIC were characterized by UV-visible light spectral analysis, reactive oxygen species (ROS) assay, and photostability testing. A pharmacokinetic study was conducted after intravenous administration of DTIC formulations (1 mg-DTIC/kg) to rats. DTIC exhibited strong absorption in the UVA range, and photoirradiated DTIC exhibited marked ROS generation. Thus, DTIC had high photoreactive potential. After exposure of DTIC (1 mM) to simulated sunlight (250 W/m2) for 3 min, remaining DTIC and yielded Diazo-IC were estimated to be ca. 230 µM and 600 µM, respectively. The addition of radical scavenger (1 mM), including l-ascorbic acid, l-cysteine (Cys), l-histidine, D-mannitol, l-tryptophan, or l-tyrosine, to DTIC (1 mM) could attenuate DTIC photoreactions, and in particular, the addition of Cys to DTIC brought ca. 34% and 86% inhibition of DTIC photodegradation and Diazo-IC photogeneration, respectively. There were no significant differences in the calculated pharmacokinetic parameters of DTIC between DTIC and DTIC with Cys (0.67 mg/kg). From these findings, the supplementary use of Cys would be an effective approach to improve the photostability of DTIC with less production of Diazo-IC.

Photochemical Mechanism of Riboflavin-Induced Degradation of Famotidine and a Suggested Pharmaceutical Strategy for Improving Photostability.

The present study aimed to clarify the mechanism of photodegradation of famotidine with riboflavin (FMT/RF), and to develop a photochemically stabilized formulation of FMT/RF. Photochemical properties of RF were characterized by UV-VIS spectral analysis, reactive oxygen species (ROS) assay, and photostability testing. Pharmacokinetic study was conducted in rats after intravenous administration of FMT (1 mg/kg) formulation containing RF (0.01 mg/kg). The UV-VIS spectral pattern of RF partly overlapped with the sunlight spectrum, and ROS generation from photoirradiated RF was remarkable; thus, RF had high photoreactive potential. In the photostability testing, after irradiation (250 W/m(2)), degradation rate for FMT in FMT/RF was ca. 11-fold higher than that in FMT alone. The addition of radical scavengers to FMT/RF led to attenuated photodegradation of FMT/RF; in particular, the addition of L-ascorbic acid (vitamin C; VC) to FMT/RF showed ca. 86% inhibition of the photodegradation of FMT/RF. The pharmacokinetic study on FMT indicated that the addition of VC (1 mg/kg) to FMT/RF had no significant impact on the pharmacokinetic behavior of FMT. These findings suggest that ROS-mediated photochemical reaction would be involved in the photodegradation pathway of FMT/RF, and the complementary use of VC might be an attractive approach to improve the photostability of FMT/RF.

[Specific variability of teicoplanin protein binding in patients receiving continuous hemodiafiltration-comparison with hypoalbuminemia patients].

Variation in protein binding ratio (PBR) of teicoplanin (TEIC) was investigated in continuous hemodiafiltration (CHDF) patients. TEIC is classified as a high PBR drug (≧90%), and it was reported that the PBR of TEIC decreased with an decrease in the serum albumin level in hypoalbuminemia patients. However, few reports can be found about the variation of PBR of TEIC for CHDF patient. An antibiotic activity is directly determined by the level of unbound antibiotics species (Cfree) in the target site, namely, an increase in the Cfree enhances the risks of TEIC as well as the therapeutic effect against Methicillin-resistant Staphylococcus aureus (MRSA). In this study, both the total concentration (Ctotal) and Cfree of TEIC were determined and the PBRs were compared between a patient with normal albumin level, hypoalbuminemia patients and CHDF patients. Similarly to the previous report, the lowering of PBR of TEIC was demonstrated in the hypoalbuminemia patients. On the other hand, the CHDF patients showed lower value of PBR suggesting some change in the protein binding ability, although showed higher values of serum albumin level in comparison with the hypoalbuminemia patients. It was not necessary to measure the Cfree value for the hypoalbuminemia patient routinely, but the monitoring of Cfree as well as Ctotal for the CHDF patients can be important for the proper TEIC use because of the potential specialty of PBR.

[Questionnaire survey of air extruded jelly dosage form (I) - oral condition of elder patients and applicability of air extruded jelly formulation - ].

Elderly patients tend to have troubles with oral conditions such as the impairment of deglutition capability (difficulty in swallowing), in addition to a decline in physical performance. An air extruded jelly formulation (AEJF) has been developed as a new formulation consisting of jelly and clean air under increased pressure. As jelly is discharged smoothly by pushing the air portion, elderly patients are able to easily take jelly from the package. In this study, survey questionnaires after a patient's trial of AEJF were conducted to characterize the intra-oral condition and reveal the applicability of AEJF in elderly patients. The subjects were 108 patients (ranging in age from 50 to 79) with chronic diseases who take some oral medicine regularly. A questionnaire on the oral state and compliance level was conducted before the trial of AEJF. The ratios of subjects with deglutition impairment and dryness of the mouth were 29.7% and 36.1%, respectively. Non-compliance was observed in 31.5% of the subjects. After the trial using AEJF, 94.5% of subjects felt that AEJF was easy to swallow. The ratio of the patients expecting AEJF to be an oral formulation was 89.3%, and those with an intention of daily use was 83.4%. A majority of the subjects, 63.9%, intended to switch their present formulations to AEJF. Especially, a high ratio was found among subjects who presently take a powder formulation or more than 5 kinds of medicines daily. Based on these results, AEJF is expected to improve the adherence of elderly patients to their medicine dosage regimens, and to improve compliance among those with oral troubles or some other hindrance to compliance.

Formulation study on retinoic acid gel composed of iota-carrageenan, polyethylene oxide and Emulgen® 408.

In the present study, all-trans retinoic acid (RA) gels formulated with various compositions of polyethylene oxide (Emulgen®) and iota-carrageenan (ι-CG) were prepared and their physicochemical properties were evaluated. The compression energy, which is the work required to compress the product through a fixed distance, increased with increasing amount of ι-CG or Emulgen®. The adhesion energy and displacement decreased with increasing amount of ι-CG or Emulgen® due to the progression of gel formation. From the results of the sensory tests, the properties of RA gels such as adhesiveness, gel strength and spreadability seemed to be adjustable depending on the condition of skin by varying the components of RA gels. Through photostability study, the expiration date and storage conditions of RA gels were determined as "4°C for 28 d with no exposure to light."

Molecular states of p-dimethylaminobenzonitrile coground with ß-cyclodextrin investigated using solid-state fluorescence spectroscopy.

Changes in molecular states of p-dimethylaminobenzonitrile (DMABN) coground with ß-cyclodextrin (ß-CD) were examined using solid-state fluorescence measurements. Formation of a DMABN/ß-CD inclusion complex by coprecipitation was confirmed by powder X-ray diffraction measurement. The powder X-ray diffraction pattern of the ground mixture was a halo pattern and differed from the pattern of the mixture prepared by coprecipitation. Solid-state fluorescence measurements revealed emission by DMABN crystals in a twisted intermolecular charge-transfer state at 473 nm. DMABN in the DMABN/ß-CD coprecipitate had a fluorescence emission peak at 393 nm due to its planar structure. In contrast, DMABN in a DMABN/ß-CD ground mixture had an emission peak at 473 nm due to its twisted structure. Grinding time-dependent structural changes in DMABN were evaluated using fluorescence lifetime and relative quantum yield measurements. Structural changes in DMABN in the DMABN/ß-CD coprecipitate from a planar to a twisted structure were observed with grinding. DMABN, dispersed in microcrystalline cellulose (CC) molecules in a DMABN/CC ground mixture, had a fluorescence emission peak at 473 nm. However, the excitation spectrum of a DMABN/ß-CD ground mixture differed from that of DMABN in CC. These results indicated that the molecular state of DMABN accommodated in the ß-CD cavity differs between the coprecipitate and the ground mixture.

Guest molecular size-dependent inclusion complexation of parabens with cholic acid by cogrinding.

Effects of p-hydroxybenzoate (paraben) ester chain length on the stoichiometry and structure of grinding-induced inclusion complexes with cholic acid (CA) were investigated. Physicochemical properties of the ground mixture were evaluated by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy, and solid-state nuclear magnetic resonance (NMR) measurements. Ethyl-, n-propyl-, and isopropyl-parabens formed equimolar inclusion complexes with CA, and the complex structures were of the ß-trans bilayer type. In contrast, the stoichiometry of the CA-paraben complex was 2:1, and the structure was of the α-gauche bilayer type when isobutylparaben was used as a guest molecule. Although the stoichiometries and structures of the complexes differed, solid-state NMR showed that the molecular states of parabens in the complexes were similar and independent of the ester chain length. Complexes between CA and parabens with longer substituent groups (C >4) were not observed. Steric effects induced by increasing the guest size are likely to influence the overall structure of inclusion complexes. Mechanical forces and thermal activation by grinding were important factors in the mechanism of CA-paraben complex formation.

Development of sarpogrelate external preparation for intractable pain control. I. Pre-formulation study on application of modified beta-cyclodextrins.

To optimize the formulation of in-hospital sarpogrelate (SPG) preparation for external use, various cyclodextrins (CDs) were investigated for their ability to improve the aqueous solubility and chemical stability of SPG. Although hydrolysis of SPG was markedly accelerated at above pH 7.0 in aqueous solution, the addition of modified beta-CD resulted in suppressed SPG hydrolysis. Addition of sulfobutylether-beta-CD (SBE-beta-CD, Captisol had the most significant stabilization effect. Phase solubility diagram and (1)H-NMR analyses indicated that dimethyl-beta-CD and SBE-beta-CD formed significantly stable inclusion complexes with SPG in aqueous solution, thereby contributing to both the increased solubility and chemical stabilization of SPG. In terms of the clinical safety of CD derivatives, SBE-beta-CD was determined to be the most suitable solubilizing agent for external SPG preparation.

[Participation of pharmacist CRC in practical on-site training--a survey by questionnaires for pharmacy students].

In order to estimate the 4th grade-students' knowledge regarding clinical trials, we carried out the questionnaire survey to the students being about to take practice in hospitals, and could collect answers from 163 students. This survey revealed that about 25% of the students could not draw the difference between "clinical trial" and "clinical research". As for the question about the technical terms regarding the clinical trial, clear correlation between students' learning experience and their knowledge was suggested. Furthermore, over 46% of the students answered that the pharmacists acting as clinical research coordinator (CRC) could not recruit new subjects, and ca. 40% of the students answered that the pharmacists acting as CRC could prescribe new drug. These misunderstandings seemed to result in the fact that most of the students could not have any chance to actually watch CRC's work related to the university curriculum. Based on the findings described above, sharing the information on the clinical trial between hospitals and universities seemed to be required to deepen students' understanding.

[Solid states fluorescence study of p-dimethylaminobenzonitrile by co-grinding with cyclodextrins].

The molecular status of a freeze-dried sample or a ground mixture of p-dimethylaminobenzonitrile (DMABN) with alpha-, beta-, or gamma-cyclodextrins (CDs) was examined using solid-state fluorescence measurements. A twisted intramolecular charge transfer (TICT) emission of DMABN crystals was shown at 475 nm. Emission peaks of freeze-dried samples were observed at 450, 380, and 393 nm in alpha-CD/DMABN, beta-CD/DMABN, and gamma-CD/DMABN systems, respectively. It was speculated that DMABN molecules existed as a twisted form in the cavity of alpha-CD, and as a plane structure in that of beta-CD or gamma-CD. On the other hand, fluorescence emission peaks of ground mixtures of DMABN with alpha-, beta-, or gamma-CD were observed at around 450 nm. When DMABN was ground together with microcrystalline cellulose, which cannot form an inclusion complex, only TICT emission was detected. These results suggest that the observed shift in the fluorescence peak could be due to inclusion phenomena. When the ground mixtures were crystallized under humid conditions, fluorescence emission peaks were observed at 450 nm in alpha-CD and of around 400 nm in beta- and gamma-CD systems. It is concluded that the conformation of the DMABN molecules in a crystalline CD/DMABN inclusion complex change depending on the size of the CD cavity.

Formulation study of intravesical oxybutynin instillation solution with enhanced retention in bladder.

A formulation study of intravesical oxybutynin (OB) preparations was carried out in order to improve the effectiveness in intravesical instillation therapy for spastic neurogenetic bladder. Sodium hyaluronate (HYA) was introduced to enhance the muco-adhesiveness of the instillation preparation, and the physicochemical properties of the OB formulation were evaluated in comparison with a conventional formulation containing hydroxypropylcellulose (HPC). The viscous properties and in vitro adhesiveness increased with the amount of the polymeric additives, and retention properties of OB in rabbit bladder were comparable after addition of 0.4% HYA and 1.0% HPC. HYA was able to enhance the intravesical retention properties of OB instillation solution to a lesser degree than HPC, it seemed to be a useful additive in the OB instillation due to its safety and mucosal-protective effect.

[Evidence-based quality management of clinical formulations: determination of expiration date of powdered medicine prepared by grinding tablets].

Beraprost sodium (BPS) is often used for pediatric patients with pulmonary hypertension. The purpose of this study was to determine the expiration date of the powdered medicine prepared by grinding tablets. In the present study, the hygroscopicity and stability of the beraprost tablet (DORNER tablet), ground Dorner tablet and powder formulation (Dorner powder) consisting of the ground DORNER tablet and lactose (EFC lactose) were investigated after storage at various relative humidities (RHs) and light exposures. While the DORNER tablets and ground DORNER tablets were found to adsorb significant amounts of water vapor at an RHs of greater than 51.0%, Dorner powder scarcely adsorbed water. The stability of BPS in the Dorner powder decreased after storage under 3000 lux for 90 days. From these results, the expiration date and storage conditions of Dorner powder were determined to "90 days without exposure to light." We also investigated the stability of BPS in solutions of various pH values on the assumption that Dorner powder may be given to pediatric patients after dissolving in soft drinks. Because BPS degraded significantly below pH 2, pharmacists should alert patients not to take Dorner powder with acidic soft drinks.

Preparation of drug nanoparticles by co-grinding with cyclodextrin: formation mechanism and factors affecting nanoparticle formation.

The aim of this study was to investigate the factors affecting the formation of pranlukast nanoparticle prepared by co-grinding with beta-cyclodextrin (beta-CD) and to elucidate the mechanism of nanoparticle formation. The effects of grinding time, moisture content and CD content on the nanoparticle formation were evaluated by means of UV quantitative determination and particle size analysis. High-resolution scanning electron microscopy (HRSEM) was employed to observe drug nanoparticles in the ground mixture. Nanoparticle recovery was higher than 95% for 2 : 1 molecular mixtures of beta-CD : pranlukast which had been ground for 10 min with moisture levels between 10 and 15%. While that of the 1 : 2 ground mixture prepared at 8% moisture level was only 57%. Nanoparticle recovery from beta-CD : pranlukast 2 : 1 mixture ground for 1 min was 2.5%, while that of the 10 min ground mixture was as high as 95%. HRSEM demonstrated that primary drug nanoparticles having a particle size around 50 nm were observed in the ground mixture. The grinding time, the moisture content, and the CD content had significant influences on the formation of drug nanoparticles. The CD matrix may form and stabilize primary particles by its interaction with the particle surface through water molecules. Primary nanoparticles existed in the ground mixture as 50 nm drug nanocrystallites.

Specific inclusion mode of guest compounds in the amylose complex analyzed by solid state NMR spectroscopy.

The inclusion compound formation between linear amylose of molecular weight 102500 (AS100) and p-aminobenzoic acid (PA) during the sealed-heating process was investigated by powder X-ray diffractometry, infrared spectroscopy and solid state NMR spectroscopy. Sealed-heating of AS100 and PA at 100 degrees C for 6 h provided an inclusion compound with 6(1)-helix structure, while a 7(1)-helix structure was found when sealed-heating was carried out at 150 degrees C for 1 h. The formation of an inclusion compound was not observed when sealed-heating was performed at 50 degrees C for 6 h. The 7(1)-helix inclusion compound maintained its structure even during storage at high temperature while the 6(1)-helix inclusion compound decomposed and returned to the original V(a)-amylose upon heating to 180 degrees C. Quantitative determination revealed that one PA molecule could be included per one helical turn of AS100 for both 6(1)-helix and 7(1)-helix inclusion compounds. Solid state NMR spectroscopy suggested that PA molecules were included in the amylose helix core in the 7(1)-helix inclusion compound, while in the case of 6(1)-helix inclusion compound, PA molecules were accommodated in the interstices between amylose helices. Moreover, the inclusion compound formation by sealed-heating of AS100 was also observed when using PA analogues as guest compounds. The binding ratio of AS100 and PA analogues varied depending on the size of guest molecules.

Micronization of phenylbutazone by rapid expansion of supercritical CO2 solution.

Rapid expansion of supercritical solutions (RESS) technique was applied for the preparation of phenylbutazone fine particles. The operating temperature and pressure affected the yield of the drug fine particles, which was evaluated by dissolving the sprayed product of drug into ethanol. Effect of pre- and post-expansion conditions on the particle size distribution of phenylbutazone was investigated and the smallest sample (mean particle size: 1.59 microm) was obtained when the RESS method was operated at a pressure of 26 MPa combined with a temperature of 32 degrees C. Physicochemical properties of the fine particles were investigated by powder X-ray diffraction and differential scanning calorimetry. It was found that the phenylbutazone fine particles obtained were meta-stable beta form under the experimental conditions tested, suggesting polymorphic transformation during the RESS process.