1
|
Ueno N, Sato H. Visualization of isothermal crystallization and phase separation in poly[(R)-3-hydroxybutyrate]/poly(L-lactic acid) by low-frequency Raman imaging. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2024; 312:124052. [PMID: 38394883 DOI: 10.1016/j.saa.2024.124052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 01/24/2024] [Accepted: 02/16/2024] [Indexed: 02/25/2024]
Abstract
The visualization of the variation of the inter/intra molecular interaction (C = O⋯CH3) between poly[(R)-3-hydroxybutyrate] (PHB) and poly-L-lactic acid (PLLA) in the PHB/PLLA miscible blend during phase separation and crystallization process was successfully investigated using Raman imaging. Images of the blend were developed using high- and low-frequency Raman spectra acquired during the isothermal crystallization of the blend, and both of them were compared. The low-frequency region allowed to observe the changes in the hydrogen bonds between the molecular chains in the blend during phase separation and crystallization via a band at 75 cm-1 derived from PHB. The imaging results obtained using the band at 75 cm-1 due to hydrogen bonding (C = O⋯CH3) between molecular chains were in good agreement with the results obtained using the C = O stretching band at 1720 cm-1. Herein, we demonstrated that the low-frequency region of the Raman spectrum is more sensitive to detecting the start of the phase separation and crystallization of PHB than the corresponding high-frequency region.
Collapse
Affiliation(s)
- Nami Ueno
- Graduate School of Human Development and Environment, Kobe University, Tsurukabuto, Nada-Ku, Kobe 657-8501, Japan
| | - Harumi Sato
- Graduate School of Human Development and Environment, Kobe University, Tsurukabuto, Nada-Ku, Kobe 657-8501, Japan; Molecular Photoscience Research Center, Kobe University, Rokkoudai, Nada-Ku, Kobe 657-8501, Japan.
| |
Collapse
|
2
|
van Haaren C, De Bock M, Kazarian SG. Advances in ATR-FTIR Spectroscopic Imaging for the Analysis of Tablet Dissolution and Drug Release. Molecules 2023; 28:4705. [PMID: 37375260 DOI: 10.3390/molecules28124705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 06/06/2023] [Accepted: 06/09/2023] [Indexed: 06/29/2023] Open
Abstract
One of the major challenges in the development of effective pharmaceutical formulations for oral administration is the poor solubility of active pharmaceutical ingredients. For this reason, the dissolution process and drug release from solid oral dosage forms, such as tablets, is usually thoroughly studied in order to understand the dissolution behaviour under various conditions and optimize the formulation accordingly. Standard dissolution tests used in the pharmaceutical industry provide information on the amount of drug released over time; however, these do not allow for a detailed analysis of the underlying chemical and physical mechanisms of tablet dissolution. FTIR spectroscopic imaging, by contrast, does offer the ability to study these processes with high spatial and chemical specificity. As such, the method allows us to see the chemical and physical processes which occur inside the tablet as it dissolves. In this review, the power of ATR-FTIR spectroscopic imaging is demonstrated by presenting a number of successful applications of this chemical imaging technique to dissolution and drug release studies for a range of different pharmaceutical formulations and study conditions. Understanding these processes is essential for the development of effective oral dosage forms and optimization of pharmaceutical formulations.
Collapse
Affiliation(s)
- Céline van Haaren
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| | - Marieke De Bock
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| | - Sergei G Kazarian
- Department of Chemical Engineering, Imperial College London, London SW7 2AZ, UK
| |
Collapse
|
3
|
Lu H, Sato H, Kazarian SG. Effect of Tm of blend components on the isothermal melt-crystallization process of PHB/PLLA blends investigated using spectroscopic imaging and DSC. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.124820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
4
|
Muroga S, Takahashi Y, Hikima Y, Ata S, Kazarian SG, Ohshima M, Okazaki T, Hata K. Novel Approaches to In-Situ ATR-FTIR Spectroscopy and Spectroscopic Imaging for Real-Time Simultaneous Monitoring Curing Reaction and Diffusion of the Curing Agent at Rubber Nanocomposite Surface. Polymers (Basel) 2021; 13:2879. [PMID: 34502918 PMCID: PMC8433895 DOI: 10.3390/polym13172879] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 08/23/2021] [Accepted: 08/24/2021] [Indexed: 12/02/2022] Open
Abstract
Here, we propose a novel attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy method for simultaneously monitoring the curing reaction and the diffusion behavior of curing agents at the surface of rubber in real-time. The proposed scheme was demonstrated by fluorine rubber (FKM) and FKM/carbon nanotube (CNT) nanocomposites with a target curing agent of triallyl-isocyanurate (TAIC). The broadening and the evolution of the C=O stretching of TAIC were quantitatively analyzed to characterize the reaction and the diffusion. Changes in the width of the C=O stretching indicated the reaction rate at the surface was even faster than that of the bulk as measured by a curemeter. The diffusion coefficient of the curing agent in the course of heating was newly calculated by the initial increase in the absorbance and our model based on Fickian diffusion. The diffusion coefficients of TAIC during curing were evaluated, and its temperature and filler dependency were identified. Cross-sectional ATR-FTIR imaging and in situ ATR-FTIR imaging measurements supported the hypothesis of the unidirectional diffusion of the curing agent towards the heated surface. It was shown that our method of in situ ATR-FTIR can monitor the degrees of cure and the diffusion coefficients of curing agents simultaneously, which cannot be achieved by conventional methods, e.g., rheological measurements.
Collapse
Affiliation(s)
- Shun Muroga
- CNT-Application Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1, Higashi, Tsukuba 305-8565, Japan
| | - Yu Takahashi
- Department of Chemical Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Yuta Hikima
- Department of Chemical Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Seisuke Ata
- CNT-Application Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1, Higashi, Tsukuba 305-8565, Japan
| | - Sergei G Kazarian
- Department of Chemical Engineering, Imperial College London, South Kensington Campus, London SW7 2AZ, UK
| | - Masahiro Ohshima
- Department of Chemical Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan
| | - Toshiya Okazaki
- CNT-Application Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1, Higashi, Tsukuba 305-8565, Japan
| | - Kenji Hata
- CNT-Application Research Center, National Institute of Advanced Industrial Science and Technology, Tsukuba Central 5, 1-1-1, Higashi, Tsukuba 305-8565, Japan
| |
Collapse
|