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Volume 25 (1998)
- Issue 5 Pages 141-
- Issue 4 Pages 83-
- Issue 3 Pages 51-
- Issue 2 Pages 33-
- Issue 1 Pages 2-
Volume 25, Issue 4
Displaying 1-11 of 11 articles from this issue
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H. Aki, M. Yamamoto1998 Volume 25 Issue 4 Pages 83
Published: September 30, 1998
Released on J-STAGE: September 07, 2009
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Satoshi Okada1998 Volume 25 Issue 4 Pages 84-85
Published: September 30, 1998
Released on J-STAGE: September 07, 2009
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Sumie Yoshioka1998 Volume 25 Issue 4 Pages 86-91
Published: September 30, 1998
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSUsefulness of thermal analysis in evaluating the storage stability of pharmaceuticals is discussed. Information on the molecular mobility of pharmaceuticals that is closely related to the stability of pharmaceuticals can be obtained from enthalpy relaxation and mechanical relaxation determined by differential scanning calorimetry, thermomechanical analysis, and dynamic mechanical analysis.View full abstractDownload PDF (742K) -
Hisashi Mimura, Satoshi Kitamura, Shigetaka Koda1998 Volume 25 Issue 4 Pages 92-96
Published: September 30, 1998
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThe application of isothermal microcalorimetry to the drug stability was investigated. Studies of reaction and decomposition kinetics under various conditions were deduced from the shapes of the heat flow curves, and the activation energy of the decomposition was determined from Arrhenius plots. The decomposition mechanisms of drugs in the presence of oxygen, water and an additive were also studied and the utility of this technique to evaluate the solid-state stability of drugs was demonstrated. Consequently, it is expected that the use of isothermal microcalorimetry would provide a direct, rapid and simple method of assessing drug stability.View full abstractDownload PDF (731K) -
Kazuhide Ashizawa1998 Volume 25 Issue 4 Pages 97-104
Published: September 30, 1998
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThe molecular details and phase transition of drug crystal were studied by thermal analysis, combination of other measurements and simultaneous measurements of X-ray diffraction (XRD) and DTA systems. In the crystalline state, methosorbinil have been shown to exist in two polymorphic crystalline forms, α- and β-form crystals by DSC and infrared spectroscopy. Transformation from the β- to α-form was observed at various heating rates, which were enhanced by the presence of a small amount of α-form crystals. Cefclidin has been shown to exist in three pseudopolymorphic crystalline forms, α-, β- and γ-form crystals by X-ray diffractometry. The relationship between the pseudopolymorphic crystal forms of cefclidin and water content was studied by X-ray diffractometry, moisture analysis and vacuum freeze drying experiments. The phase transition of crystalline cefclidin clearly indicated the effect of water content on dehydration. In studying phase transition of pseudopolymorphism of E4031 and E3060, XRD-DTA system technique which describe characterization of the phase transition of pseudopolymorphism has been developed. The present study clarified the phase behavior of pharmaceuticals with thermodynamics, and spectroscopic, and newly XRD-DTA system technique.View full abstractDownload PDF (1891K) -
Katsuhide Terada, Yasuo Yoshihashi1998 Volume 25 Issue 4 Pages 105-110
Published: September 30, 1998
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSCrystallinity of drug substance was evaluated by powder X-ray diffraction methods and thermal methods, DSC and microcalorimetry. Terfenadine was used as drug substance and different crystallinity samples were prepared by grinding. The crystallinity of terfenadine decreased with the increase in grinding time. The dissolution rates were increased as the crystallinity of terfenadine decreased. Linear correlation was obtained between crystallinity and logarithm of dissolution rate of terfenadine. Especially, the crystallinity obtained by the thermal methods was well linearly correlated with solubility data in almost all crystallinity region.
It was confirmed that the thermal methods were useful for the quality control of crystallinity of drug substance. Thermal method is also efficient for the characterization of amorphous state.View full abstractDownload PDF (705K) -
Etsuo Yonemochi, Keiji Yamamoto1998 Volume 25 Issue 4 Pages 111-116
Published: September 30, 1998
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThis review describes the interaction between drug and pharmaceutical additives. The potential compatibility of several commonly used pharmaceutical additives with picotamide was evaluated using DSC. Mechanical treatments (blending, grinding, or kneading) of samples were also evaluated. Mechanical stress displayed an increased hygroscopicity of mixtures with glucose and lactose, as well as some solid-solid interactions with lactose. DSC studies have been carried out with amorphous solid dispersions of indomethacin and PVP. Values of glass transition temperature as a function of mixture composition followed the ideal Cordon-Taylor equation up to about 50% PVP. Thermal properties of ethenzamide in the mixtures with porous additives, porous crystalline cellulose and controlled pore glasses, were investigated by DSC. In the DSC curves of the mixtures of drug and the porous additives, an anomalous endothermic peak was observed. This endothermic peak was related to the adsorption of the drug into the pore of porous additives. Thermal behaviors of the mixture of benzoic acid or methyl-p-hydroxybenzoate with cyclodextrins were studied by DSC. Several thermal events were observed on the DSC curves, which were assigned to the inclusion formation and the release of the guest molecules from inclusion compound by X-ray diffractomertry and infrared spectrometry.View full abstractDownload PDF (863K) -
Hatsumi Aki, Magobei Yamamoto1998 Volume 25 Issue 4 Pages 117-125
Published: September 30, 1998
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSIsothermal titration calorimetry has been employed to evaluate inclusion mechanism associated with complexation between 2-hydroxypropyl-β-cyclodextrin (HPβCD) and barbiturates (BAs). The association constants, stoichiometry, and enthalpic changes were calculated from calorimetric titration curves using a non-linear least squares method. The inclusion modes (structures) were explored by relating the thermodynamic parameters to the chemical structures of BAs molecule and the cavity size of HPβCD. Two different types of BAs-HPβCD inclusion complexes at 1:1 stoichiometry were realized by un-ionized BAs, whereas only one type of inclusion was by barbital. The first type of BAs-HPβCD with higher association constant was largely entropically driven with the constant values of ΔG1, ΔH1 and ΔS1 at various pH, thus the hydrophobic interaction dominated the stabilization of the complexes. The second type was characterized by large negative values of ΔH2 and small ΔS2 at pH < pKa values of BAs, reflecting van der Waals' interaction and/or hydrogen bonding formation, and all the thermodynamic parameters markedly decreased at pH > pKa. It is indicated that the R2 substituent at 5C in barbituric acid ring of BAs was included within HPβCD cavity in the first type of com-plexes and that the barbituric acid ring penetrated into the cavity in th second type. In both types, the ethyl-side chain of R1 substituent remained out-side of the cavity. The results were agreed with those from 13C-NMR spectrometry. The inclusion geometry of the complexes were estimated by molecular dynamics calculations.View full abstractDownload PDF (1243K) -
Takamitsu Kosa, Hiroshi Watanabe, Masaki Otagiri1998 Volume 25 Issue 4 Pages 126-131
Published: September 30, 1998
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSThis review is written to evaluate the possible utility of thermal measurement in the interaction study of drug with serum albumin. DSC measurement showed that species difference exist with respect to the conformational stability and the mechanism of unfolding pathway for mammalian albumin. In addition, the existence of three binding sites on human serum albumin molecule was confirmed from flow microcalorimetry. Moreover, the chemical and biological stability of oxidized albumin was mentioned. This discussion will be useful in the development of knowledge about structure and function of biopolymers including serum albumin.View full abstractDownload PDF (880K) -
Fumihiro Okada1998 Volume 25 Issue 4 Pages 132-137
Published: September 30, 1998
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSUsing microbial calorimetry technique, the antimicrobial actions of drugs were quantitatively studied for p-hydroxybenzoic acid alkyl esters (parabens). Parabens testd were p-hydroxybenzoic acid methyl, ethyl, propyl, butyl, pentyl and hexyl esters.
For the purpose of obtaining the inhibitory parameters characterizing drug action, growth behaviors of Saccharomyces cerevisiae and Klebsiella pneumoniae grown in media containing various amounts of parabens were observed as each growth thermogram with the multiplex calorimeter having 24 calorimetric units. Based on the growth thermograms of Klebsiella pneumoniae and Saccharomyces cerevisiae, 50% growth inhibition concentrations (Kθs) of each paraben were obtained from the growth retardation times, and then the drug-potency curves were made from the drug efficacy. The minimum growth inhibition concentrations (MICs) obtained by analyzing the drug-potency curves showed that the effects of the drugs become more in the order of methyl, ethyl, propyl, butyl, pentyl, hexyl esters. When comparing the affinity of the drugs to both microorganisms based on the drug concentration required for inhibiting the growth activity by 50%, a linear relationship was observed to exist between the number of carbon atoms in an alkyl chain and the affinity. In addition, an identical drug exhibited a higher effect on S. cerevisiae rather than on K. pneumoniae, which may be mainly due to the difference in membrane structure.
From the result obtained it was concluded that the method of analysis developed here is useful for the quantitative study of antimicrobial actions of drugs.View full abstractDownload PDF (938K) -
1998 Volume 25 Issue 4 Pages 138
Published: September 30, 1998
Released on J-STAGE: September 07, 2009
JOURNAL FREE ACCESSDownload PDF (151K)
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