IGARASHI Koichi

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Title

Associate Professor

Laboratory location

Sugimoto Campus

Degree 【 display / non-display

  •  -  Master of Engineering

Research Areas 【 display / non-display

Biochemical Engineering, Industrial crystallization

Research Interests 【 display / non-display

Industrial crystallization

Research Career 【 display / non-display

  • Utilization of woody biomass

    (Collaboration in Organization)

    Keyword in research subject:  woody biomass, hydrothermal treatment, lignin

  • Development of novel crystallizer

    (Individual)

    Keyword in research subject:  crystallization, crystallizer, crystal characreristics

  • Crystallization of pharmaceutical compound, control of crystal polymorph

    (Individual)

    Keyword in research subject:  crystallization, pharmaceutical compound, polymorph

Awards & Honors 【 display / non-display

  • Best poster award, BIWIC 2004, Gyeongju, Korea

    2004  

  • Outstanding paper award, Journal of Chemical Engineering of Japan

    2013  

  • Best poster award, Asian crystallization Technology Symposium 2012

    2011  

  • Outstanding paper award, 8th International Conference on Separation Science and Technology, Nagano

    2008  

Current Career 【 display / non-display

  • Osaka City University   Graduate School of Engineering   Applied Chemistry and Bioengineering Course   Associate Professor  

Graduate School 【 display / non-display

  •  
    -
    1998

    Osaka City University  Graduate School, Division of Engineering 

 

Published Papers 【 display / non-display

  • Simultaneous Control of Crystal Habit and Particle Size of Ecabet Sodium Hydrate with Rapid Cooling Crystallization and Temperature Cycling

    Kishida Muneki, Igarashi Koichi, Azuma Masayuki, Ooshima Hiroshi

    JOURNAL OF CHEMICAL ENGINEERING OF JAPAN  52 ( 5 ) 455 - 464 2019.05  [Refereed]

     View Summary

    <p>A practical strategy for the simultaneous control of particle size and shape of active pharmaceutical ingredients has been investigated using ecabet sodium (Na-ECA) hydrate, which tends to generate large plate-like crystals, as a model compound. In conventional batch-cooling crystallization, particle size and relative thickness decreased with increasing cooling rates. However, the particle size was still too large following fast cooling at a rate of 40°C/h. In rapid cooling crystallization with water, achieved by mixing hot Na-ECA solution with cold water, the particle size and relative thickness became 1/3.8 and 1/3, respectively, compared to that under batch-cooling crystallization at a rate of 40°C/h. It was also revealed that both the particle size and relative thickness increased with temperature cycling; however, the morphology of the obtained particles was still plate-like. In rapid cooling crystallization in aqueous NaCl, the particle size was reduced further to 1/4.7, and the relative thickness of the particle increased sixfold over that obtained in water. Moreover, the shape of the particle evolved effectively by temperature cycling. Consequently, granular and smaller particles could be obtained successfully. The mechanism of shape evolution was also discussed with respect to contact angles. Based on the qualitative analysis results obtained using Young's equation, we propose that shape evolution is induced by surface free energy, which drives the progression towards equilibrium shape during repeated partial dissolution and crystal growth.</p>

    DOI CiNii

  • Recovering metals from aqueous solutions by biosorption onto phosphorylated dry baker's yeast

    Ojima Yoshihiro, Kosako Shogo, Kihara Maya, Miyoshi Norikazu, Igarashi Koichi, Azuma Masayuki

    SCIENTIFIC REPORTS  9 2019.01  [Refereed]

    DOI

  • Pharmaceutical Microcrystal Formation by Supersaturation Control with an Electrolyte

    Muneki Kishida, Koichi Igarashi, Masayuki Azuma and Hiroshi Ooshima

    Journal of Chemical Engineering of Japan  51 ( 7 ) 1 - 6 2018.07  [Refereed]

     View Summary

    Methods to control the particle sizes of active pharmaceutical ingredients were investigated using sodium ecabet (Na-ECA) hydrate, which tends to generate large plate-like crystals, as a model compound. In batch-cooling crystallization in H2O, the particle size decreased as the cooling rate was increased. Although the particle size reached 97 µm at a cooling rate of 40°C/h, this may be too large for formulation without further physical processing. A series of semi-batch crystallization experiments was conducted by adding aqueous Na-ECA solution to aqueous NaCl. In these experiments, the particle sizes decreased to less than 7 µm as the NaCl concentration was increased to >1.2% w/w. The particles yielded by semi-batch crystallization showed improved particle size distributions compared to those obtained by the batch-cooling crystallization method. The solubility of Na-ECA hydrate decreased to less than 10% of that in pure water as the NaCl concentration was increased to 3.0% w/w. This solubility change enabled the production of a highly supersaturated environment, allowing facile generation of microcrystals with a narrow particle size distribution.

  • Behavior of t-Butoxycarbonyl-L-asparagine (Boc-Asn) during the Initial Stage of Crystallization

    Igarashi Koichi, Aoki Masako, Masuda Yoshiko, Azuma Masayuki, Ooshima Hiroshi

    Journal of Chemical Engineering of Japan  51 ( 1 ) 111 - 115 2018.01  [Refereed]

     View Summary

    <p>The crystallization mechanism of amino acid derivative <i>t</i>-butoxycarbonyl-L-asparagine (Boc-Asn) was investigated. NMR spectroscopy was used to observe the behavior of Boc-Asn molecules in under- and supersaturated solution. Nuclear Overhauser Effect (NOE) NMR measurements were performed to provide information concerning the intra- or intermolecular access of a particular hydrogen atom to other hydrogen atoms in solution. We compared the interactions identified by NOE measurements for under- and supersaturated solutions of Boc-Asn with those in the crystal, as determined by X-ray analysis. According to the X-ray analysis, intramolecular NOE should not be observed, but intermolecular NOE might be observed between the methyl protons of the <i>t</i>-butoxycarbonyl group and the protons belonging to other functional groups. The time course of the NOE intensity was followed for three solutions with different saturation ratios <i>S</i> (=concentration of solute/solubility). For undersaturated and nearly saturated conditions (<i>S</i>=0.8 and 1.12 at 0°C), the NOE intensity did not change for at least for 250 h. However, for the supersaturated solution (<i>S</i>=1.62 at 10°C), the NOE intensity increased suddenly and rapidly after about 120 h, and no crystals were observed during the NOE measurements. As the observed NOEs agreed with those expected from the arrangement of molecules in the crystal, it was suggested that Boc-Asn molecules aggregated after about 120 h with the same structure as that in the crystal. In addition to the behavior of the Boc-Asn solution before nucleation, we also investigated the effect of aggregation on the crystallization process. Solutions that were preincubated at 10°C for various periods were further cooled and crystallized at −30°C. It was found that when the solution was preincubated under the supersaturated condition for a long time before crystallization, nucleation was enhanced, and consequently, the crystal size distribution became homogeneous.</p>

    DOI CiNii

  • Localized Solvent Effects on the Crystal Habit of tert-Butoxycarbonyl-L-asparagine (BocASN)

    Hirano Masaru, Igarashi Koichi, Ooshima Hiroshi

    JOURNAL OF CHEMICAL ENGINEERING OF JAPAN  50 ( 3 ) 207 - 212 2017.03  [Refereed]

     View Summary

    <p>Solvent selection is one of the most important factors for the control of crystal habits. However, this relationship is poorly understood. The aim of this study was to determine the solvent selectivity to obtain a desired crystal habit using <i>tert</i>-butoxycarbonyl-L-asparagine (BocASN) as a model compound. The [110], [100], and [001] faces were dominant for the BocASN crystals obtained from acetone and ethanol. However, the [011], [100], and [001] faces were dominant for those obtained from methanol. The interactions between the solvent molecules and the functional groups exposed on the crystal surface were examined. The solvent-surface interactions on each surface of the BocASN crystal were dependent on the type of solvent. The different solvent-surface interactions along the <i>a</i>-, <i>b</i>-, and <i>c</i>-axes affected the growth rate and aspect ratio of the crystal. The analysis of the solvent-surface interactions is useful to predict the crystal habit.</p>

    DOI CiNii

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Conference Activities & Talks 【 display / non-display

  • Promotion of crystal nucleation of L-alanine by plastic piece moving in the solution

    K. Igarashi, T. Kobayashi, H. Ooshima  [Invited]

    13th Korea-Japan Symposium on Materials and Interfaces  2018.11 

  • Determination of solubility of Extremely Poor water solubility co-crystal melamine cyanurate

    Koichi Igarashi, Ryoto yanagita, Joop ter Horst

    13th International Workshop of the Crystal Growth of Organic Material  2018.08 

  • Control of Crystal Size Distribution Using a mL-Scale Continuous Crystallizer Equipped with a High Speed Agitator

    Koichi Igarashi, and Hiroshi Ooshima  [Invited]

    International Powder and Nanotechnology Forum 2018 in ACHEMA  2018.06 

  • Effect of plastic piece moving in the solution on crystal nucleation of L-alanine

    K. Igarashi, T. Kobayashi, and H. Ooshima

    Asian Crystallization Technology Symposium 2018  2018.06 

  • Crystallization of a tripeptide from the oil phase

    K. Igarashi, H. Ooshima

    11th International Conference on Separation Science and Technology (ICSST17)  2017.11 

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Grant-in-Aid for Scientific Research 【 display / non-display

  • Control of crystallization nucleation of organic compounds in recognizing of the importance of solution structure and its application for production of nano crystals

    Project/Area Number : 21560781  Grant-in-Aid for Scientific Research(C) Partaker / Other

    Project Year :

    2009
    -
    2011
     

    Partaker : IGARASHI Koichi

     View Summary

    Chemical structure of pharmaceutical compounds evolves to become complex and hard to dissolve. To increase bioavailability of drugs, we must produce fine crystals of drugs by controlling the nucleation step of crystallization. However, the mechanism of nucleation has not been well understood. In the present study, we found for the first time that the control of the change of molecular associate structure and the control of diffusion of molecules are important to control nucleation. Furthermore, we attempted some processes to produce fine crystals.

  • Study on discontinuous nonequilibrium mechanism in crystal nucleation and its application to production of nanocrystals

    Project/Area Number : 19560758  Grant-in-Aid for Scientific Research(C) Partaker / Other

    Project Year :

    2007
    -
    2008
     

    Partaker : IGARASHI Koichi

  • Nucleation Mechanism of Organic Compound Crystals and Crystallization for Production of Nano-Medicine

    Project/Area Number : 17560664  Grant-in-Aid for Scientific Research(C) Partaker / Other

    Project Year :

    2005
    -
    2006
     

    Partaker : IGARASHI Koichi

     View Summary

    1. In order to elucidate mechanism of crystal nucleation of organic compounds, the relationship between crystallization of polymorphs of an organic compound BPPI(C16H12C12F3N302) and the solution structure was investigated. The B02 form of BPPI crystals was precipitated from a methanol solution and the B01 form appeared from an ethanol solution. We compared crystal structures of those polymorphs with each solution structures determined by NMR analysis for solution. As a result, it was found that the conformation of BPPI molecules in each solution was similar to that of BPPI molecules forming each polymorph. The structure of molecular aggregates formed in each solution before nucleation was also similar to each crystal structure. However the structure of molecular aggregates was not completely the same as the corresponding crystal structure. This suggests that nucleation requires structure-transformation of molecular aggregates from a certain random structure to a crystal structure, namely the structure-transformation step should be the nucleation. We also obtained a result suggesting a novel concept about nucleation, that is the propagation of nucleation in solution.
    2. We showed that the irradiation of microwave during crystallization suppresses nucleation even under a high super-saturation. The controlled suppression of nucleation must play an important role for production of crystals with small size and a narrow size distribution.
    3. We developed a novel continuous crystallizer with a mL-scale for production of micro crystals and production of an unstable polymorph. We could operate this crystallizer at a mean residence time of sub-second without clogging of crystals.

 

Other educational activity and Special note 【 display / non-display

  • Contribution to FD activities

    (2014)

Educational activity record 【 display / non-display

  • Academic year : 2018

     View Details

    Number of instructed the graduation thesis
    4
    Number of graduation thesis reviews
    4
    Number of instructed the Master course
    2
    Number of instructed the Doctoral course
    1
    Number of master's thesis reviews (chief)
    1
    Number of master's thesis reviews (vice-chief)
    0
    Number of doctoral thesis reviews (chief)
    0
    Number of doctoral thesis reviews (vice-chief)
    0
  • Academic year : 2017

     View Details

    Number of instructed the graduation thesis
    3
    Number of graduation thesis reviews
    3
    Number of instructed the Master course
    3
    Number of instructed the Doctoral course
    0
    Number of master's thesis reviews (chief)
    2
    Number of master's thesis reviews (vice-chief)
    0
    Number of doctoral thesis reviews (chief)
    0
    Number of doctoral thesis reviews (vice-chief)
    0
  • Academic year : 2014

     View Details

    Number of instructed the graduation thesis
    5
    Number of graduation thesis reviews
    2
    Number of instructed the Master course
    4
    Number of instructed the Doctoral course
    0
    Number of master's thesis reviews (chief)
    0
    Number of master's thesis reviews (vice-chief)
    1
    Number of doctoral thesis reviews (chief)
    0
    Number of doctoral thesis reviews (vice-chief)
    0
 

Theme of Possible Research Exchange 【 display / non-display

  • Industrial Crystallization

    Research theme : ***

    Keyword : crystallization, organic compound, protein

     View Details

    Application fields / methods etc : ***

    Core knowledge, technology, information etc : ***