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Inoue M, Hisada H, Takatori K, Koide T, Fukami T, Roy A, Carriere J. Solid-State Analysis of Alpha-Cyclodextrin Inclusion Complexes Using Low-Frequency Raman Spectroscopy. Anal Chem 2021; 93:704-708. [PMID: 33284586 DOI: 10.1021/acs.analchem.0c03854] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A rapid and nondestructive analytical technique is critical for the analysis of cyclodextrin inclusion complexes in solid dosage forms. This study proposed a newly developed low-frequency Raman spectroscopy as a candidate technique for the analysis of cyclodextrin inclusion complexes. In this study, we selected a typical series of five crystalline cyclodextrin inclusion complexes and reported the usefulness of Raman spectroscopy for analyzing these inclusion complexes. Some inclusion complexes clearly differed from the raw materials in conventional Raman spectra. In another case, though specific differences were not observed between inclusion complexes and raw materials in conventional Raman spectra, clear differences were observed in low-frequency Raman spectra. Moreover, no characteristic differences between inclusion complexes consisting of different guest molecules were observed in conventional Raman spectra. The characteristic differences were observed only in low-frequency Raman spectra. Therefore, low-frequency Raman spectroscopy is a useful technique for solid-state analysis of crystalline inclusion complexes.
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Affiliation(s)
- Motoki Inoue
- Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Hiroshi Hisada
- Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Kazuhiko Takatori
- Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Tatsuo Koide
- National Institute of Health Sciences, 3-25-26, Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-9501, Japan
| | - Toshiro Fukami
- Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose, Tokyo 204-8588, Japan
| | - Anjan Roy
- Coherent Inc., 850 East, Duarte Road, Monrovia, California 91016, United States
| | - James Carriere
- Coherent Inc., 850 East, Duarte Road, Monrovia, California 91016, United States
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2
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Liu X, Michalchuk AAL, Pulham CR, Boldyreva EV. An acetonitrile-solvated cocrystal of piroxicam and succinic acid with co-existing zwitterionic and non-ionized piroxicam molecules. ACTA CRYSTALLOGRAPHICA SECTION C-STRUCTURAL CHEMISTRY 2019; 75:29-37. [PMID: 30601128 DOI: 10.1107/s2053229618016911] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2018] [Accepted: 11/28/2018] [Indexed: 11/10/2022]
Abstract
This work reports a new acetonitrile (ACN)-solvated cocrystal of piroxicam (PRX) and succinic acid (SA), 2C15H13N3O4S·0.5C4H6O4·C2H3N or PRX:SA:ACN (4:1:2), which adopts the triclinic space group P-1. The outcome of crystallization from ACN solution can be controlled by varying only the PRX:SA ratio, with a higher PRX:SA ratio in solution unexpectedly favouring a lower stoichiometric ratio in the solid product. In the new solvate, zwitterionic (Z) and non-ionized (NI) PRX molecules co-exist in the asymmetric unit. In contrast, the nonsolvated PRX-SA cocrystal contains only NI-type PRX molecules. The ACN molecule entrapped in PRX-SA·ACN does not form any hydrogen bonds with the surrounding molecules. In the solvated cocrystal, Z-type molecules form dimers linked by intermolecular N-H...O hydrogen bonds, whereas every pair of NI-type molecules is linked to SA via N-H...O and O-H...N hydrogen bonds. Thermogravimetry and differential scanning calorimetry suggest that thermal desolvation of the solvate sample occurs at 148 °C, and is followed by recrystallization, presumably of a multicomponent PRX-SA structure. Vibrational spectra (IR and Raman spectroscopy) of PRX-SA·ACN and PRX-SA are also used to demonstrate the ability of spectroscopic techniques to distinguish between NI- and Z-type PRX molecules in the solid state. Hence, vibrational spectroscopy can be used to distinguish the PRX-SA cocrystal and its ACN solvate.
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Affiliation(s)
- Xiaojiao Liu
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, Joseph Black Building, Edinburgh EH9 3FJ, Scotland
| | - Adam A L Michalchuk
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, Joseph Black Building, Edinburgh EH9 3FJ, Scotland
| | - Colin R Pulham
- EaStCHEM School of Chemistry and Centre for Science at Extreme Conditions, University of Edinburgh, Joseph Black Building, Edinburgh EH9 3FJ, Scotland
| | - Elena V Boldyreva
- Boreskov Institute of Catalysis, Siberian Branch of Russian Academy of Sciences, pr. Lavrentieva 5, Novosibirisk 630090, Russian Federation
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3
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Kuroiwa Y, Higashi K, Ueda K, Yamamoto K, Moribe K. Nano-scale and molecular-level understanding of wet-milled indomethacin/poloxamer 407 nanosuspension with TEM, suspended-state NMR, and Raman measurements. Int J Pharm 2018; 537:30-39. [DOI: 10.1016/j.ijpharm.2017.12.028] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 12/04/2017] [Accepted: 12/11/2017] [Indexed: 01/24/2023]
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4
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Hasegawa Y, Higashi K, Yamamoto K, Moribe K. Direct Evaluation of Molecular States of Piroxicam/Poloxamer Nanosuspension by Suspended-State NMR and Raman Spectroscopies. Mol Pharm 2015; 12:1564-72. [DOI: 10.1021/mp500872g] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Yuki Hasegawa
- Graduate School of Pharmaceutical
Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Kenjirou Higashi
- Graduate School of Pharmaceutical
Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Keiji Yamamoto
- Graduate School of Pharmaceutical
Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
| | - Kunikazu Moribe
- Graduate School of Pharmaceutical
Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8675, Japan
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5
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Suzuki T, Ei A, Takada Y, Uehara H, Yamanobe T, Takahashi K. Modification of physical properties of poly(L-lactic acid) by addition of methyl-β-cyclodextrin. Beilstein J Org Chem 2015; 10:2997-3006. [PMID: 25670970 PMCID: PMC4311664 DOI: 10.3762/bjoc.10.318] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Accepted: 11/24/2014] [Indexed: 11/29/2022] Open
Abstract
Poly(L-lactic acid) (PLLA) is a biodegradable plastic and one of the most famous plastics made from biobased materials. However, its physical strength is insufficient compared to general-purpose plastics. In this study, the effect of methylcyclodextrin (MeCD) addition on the structure and physical properties, especially the drawing behavior, of PLLA was investigated. Through thermal analysis, it was found that MeCD addition lowers the crystallinity and enhances the mobility of PLLA. The sample containing approximately 17% MeCD was drawn to more than 1000% at 60 °C, although PLLA fractured at a strain of less than 100%. Differential scanning calorimetry (DSC)-Raman in situ measurements also revealed decreases in the glass transition temperature (Tg), cold crystallization temperature (Tc), and melting point (Tm), and improvement in structural distribution with temperature. DSC-Raman measurements simultaneously supplied information about crystallinity and thermal properties. Thus, it was concluded that MeCD had high affinity for PLLA, and the addition of MeCD increased the amorphous component of PLLA and enhanced the drawability.
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Affiliation(s)
- Toshiyuki Suzuki
- Perkin-Elmer Japan Co. Ltd., 134 Godo-cho, Hodogaya-ku, Yokohama-shi 240-0004, Japan; ; Gunma University, 1-5-1 Tenjin-cho, Kiryu-shi, Gunma 376-8515, Japan; Fax: +81-277-30-1331
| | - Ayaka Ei
- Gunma University, 1-5-1 Tenjin-cho, Kiryu-shi, Gunma 376-8515, Japan
| | - Yoshihisa Takada
- Gunma University, 1-5-1 Tenjin-cho, Kiryu-shi, Gunma 376-8515, Japan
| | - Hiroki Uehara
- Gunma University, 1-5-1 Tenjin-cho, Kiryu-shi, Gunma 376-8515, Japan
| | - Takeshi Yamanobe
- Gunma University, 1-5-1 Tenjin-cho, Kiryu-shi, Gunma 376-8515, Japan
| | - Keiko Takahashi
- Tokyo Polytechnic University, 1583 Iiyama, Atsugi 243-0297, Japan; Fax +81-46-242-3000
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Xia J, Song LX, Dang Z. Low-Temperature Carbonization and More Effective Degradation of Carbohydrates Induced by Ferric Trichloride. J Phys Chem B 2012; 116:7635-43. [DOI: 10.1021/jp303041v] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Juan Xia
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, People's
Republic of China
| | - Le Xin Song
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, People's
Republic of China
- State
Key Laboratory of Coordination
Chemistry, Nanjing University, Nanjing
210093, People's Republic of China
| | - Zheng Dang
- Department of Chemistry, University of Science and Technology of China, Hefei 230026, People's
Republic of China
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7
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Liu W, Wang WD, Wang W, Bai S, Dybowski C. Influence of Structure on the Spectroscopic Properties of the Polymorphs of Piroxicam. J Phys Chem B 2010; 114:16641-9. [DOI: 10.1021/jp1084444] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- Wei Liu
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu, 730000, China, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Wei David Wang
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu, 730000, China, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Wei Wang
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu, 730000, China, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Shi Bai
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu, 730000, China, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Cecil Dybowski
- State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou, Gansu, 730000, China, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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8
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Infrared spectra of monosubstituted toluene derivatives in cyclodextrin: Orientation of guest molecules in included complexes. J Mol Struct 2009. [DOI: 10.1016/j.molstruc.2009.04.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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9
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A one-pot method to enhance dissolution rate of low solubility drug molecules using dispersion polymerization in supercritical carbon dioxide. Int J Pharm 2009; 377:60-9. [DOI: 10.1016/j.ijpharm.2009.05.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2009] [Accepted: 05/01/2009] [Indexed: 11/23/2022]
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10
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El-Gamel NEA. The interactions of metal ions with nonsteroidal anti-inflammatory drugs (oxicams). J COORD CHEM 2009. [DOI: 10.1080/00958970902822630] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Nadia E. A. El-Gamel
- a Faculty of Science, Chemistry Department , Cairo University , 12613 Giza, Egypt
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11
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Raman spectroscopy is a convenient technique for the efficient evaluation of cyclodextrin inclusion molecular complexes of azo-dye colorants and largely polarisable guest molecules. J INCL PHENOM MACRO 2009. [DOI: 10.1007/s10847-009-9538-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Crupi V, Ficarra R, Guardo M, Majolino D, Stancanelli R, Venuti V. UV–vis and FTIR–ATR spectroscopic techniques to study the inclusion complexes of genistein with β-cyclodextrins. J Pharm Biomed Anal 2007; 44:110-7. [PMID: 17379467 DOI: 10.1016/j.jpba.2007.01.054] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2006] [Revised: 01/29/2007] [Accepted: 01/31/2007] [Indexed: 10/23/2022]
Abstract
The effect of beta-cyclodextrin (beta-CyD), (2-hydroxypropyl)-beta-cyclodextrin (HP-beta-CyD) and methyl-beta-cyclodextrin (Me-beta-CyD) complexation on the UV absorption of genistein (Gen) was studied in pure water. A phase solubility study was performed, according to the method reported by Higuchi and Connors, to evaluate the changes of isoflavone in the complexation state and the obtained diagrams suggested that it forms complexes with a stoichiometry of 1:1. Then, the solid complexes of genistein with these macrocycles in 1:1 molar ratio were prepared by the co-precipitation method and characterized by FTIR absorption spectroscopy in ATR geometry. The host-guest interactions have been evidenced by monitoring, in the FTIR-ATR spectra, the changes in some guest molecule bands relative to those observed in the spectra of the 1:1 physical mixtures and complexes. In particular, for the high-frequency O-H stretching band, a quantitative vibrational assignment of the observed sub-bands has been made. From the results, the inclusion phenomena have been discussed.
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Affiliation(s)
- V Crupi
- Dipartimento di Fisica, Facoltà di Scienze MM.FF.NN., Università di Messina, C.da Papardo, S.ta Sperone 31, P.O. Box 55, 98166 S. Agata, Messina, Italy
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13
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Rozou S, Voulgari A, Antoniadou-Vyza E. The effect of pH dependent molecular conformation and dimerization phenomena of piroxicam on the drug:cyclodextrin complex stoichiometry and its chromatographic behaviour. Eur J Pharm Sci 2004; 21:661-9. [PMID: 15066667 DOI: 10.1016/j.ejps.2004.01.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2003] [Revised: 12/30/2003] [Accepted: 01/16/2004] [Indexed: 10/26/2022]
Abstract
The complexation of piroxicam with various cyclodextrins was studied in the whole pH range, in an attempt to clarify the reported differences in stoichiometry of the resulting inclusion complexes. In this work, it was found that the pH dependent self-association phenomena, detected in both alkaline and acidic media, are the defining features for complex stoichiometry. Also, it was observed that the inclusion complexes of the piroxicam zwitterion with beta-cyclodextrin (beta CD), methyl-beta-cyclodextrin and hydroxypropyl-beta-cyclodextrin have a 2:2 stoichiometry in acidic pH, through inclusion of the benzyl ring moiety. As pH increased, it was determined that the different ionic state of the molecules creates new geometries, involving also the pyridyl-ring in the complexation. More stable inclusion complexes of 2:5 stoichiometry are observed at pH>4. A reversed phase liquid chromatography method, specific for the analysis of the included piroxicam, was developed and validated. The different stoichiometries and the dimers formation were investigated by interpretation of the two-dimensional 1H NMR spectroscopy.
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Affiliation(s)
- Stavroula Rozou
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Athens, Panepistimiopolis Zografou, Athens 15771, Greece
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14
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Xiliang G, Yu Y, Guoyan Z, Guomei Z, Jianbin C, Shaomin S. Study on inclusion interaction of piroxicam with beta-cyclodextrin derivatives. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2003; 59:3379-3386. [PMID: 14607235 DOI: 10.1016/s1386-1425(03)00164-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The inclusion behavior of piroxicam (PX) with beta-cyclodextrin (beta-CD), hydroxypropyl-beta-cyclodextrin (HP-beta-CD), and carboxymethyl-beta-cyclodextrin (CM-beta-CD) was investigated by using steady-state fluorescence and nuclear magnetic resonance (NMR) technique. The various factors affecting the inclusion process were examined in detail. The remarkable fluorescence emission enhancement upon addition of CDs suggested that cyclodextrins (CDs) were most suitable for inclusion of the uncharged species of PX. The stoichiometry of the PX-CDs inclusion complexes was 1:1, except for beta-CD where a 1:2 inclusion complex was formed. The formation constants showed the strongest inclusion capacity of beta-CD. NMR showed the inclusion mode of PX with CDs.
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Affiliation(s)
- Guo Xiliang
- Department of Chemistry, College of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, China
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15
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Vibrational and thermal characterisation of a new chiral drug under investigation for the therapy of congestive heart failure. J Mol Struct 2002. [DOI: 10.1016/s0022-2860(02)00349-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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16
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Taddei P, Torreggiani A, Fini G. Vibrational study of polymorphism of tetralin derivative for treatment of cardiovascular diseases. Biopolymers 2002; 67:289-93. [PMID: 12012450 DOI: 10.1002/bip.10089] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Vibrational spectroscopy coupled with thermogravimetry (TG) and differential scanning calorimetry (DSC) was used to characterize racemic propanoic acid, 2-methyl-5,6,7,8-tetrahydro-6-(methylamino)-1,2-naphthalenediyl ester hydrochloride (CHF-1035), which is a new DA2 dopaminergic receptor/alpha2 agonist and beta blocker under clinical investigation for the treatment of congestive heart failure. Raman spectroscopy disclosed at least two different CHF-1035 polymorphs; the marker bands characteristic of each form were identified. The modifications undergone by the CHF-1035 drug as a consequence of grinding and heating were investigated. Mechanical and gentle thermal treatments caused a polymorphic transformation of the drug crystal form. Raman spectroscopy proved suitable for investigating the possible presence of different polymorphic forms, their relative stability, and interconversion tendency in relation to industrial manufacturing processes undergone by the drug (i.e., grinding, compression, and heating).
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Affiliation(s)
- Paola Taddei
- Dipartimento di Biochimica G. Moruzzi, Sezione di Chimica e Propedeutica Biochimica, University of Bologna, Via Belmeloro 8/2, 40126, Italy
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17
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Van Hees T, Piel G, de Hassonville SH, Evrard B, Delattre L. Determination of the free/included piroxicam ratio in cyclodextrin complexes: comparison between UV spectrophotometry and differential scanning calorimetry. Eur J Pharm Sci 2002; 15:347-53. [PMID: 11988396 DOI: 10.1016/s0928-0987(02)00018-0] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Few analytical techniques allow to evaluate the inclusion yield of cyclodextrin-drug complexes, because most manufacturing processes give amorphous products. In this study, we have developed an alternative method to differential scanning calorimetry, to accurately determine the free/complexed piroxicam ratio by UV spectroscopy. This method is based on the differential solubility of the piroxicam-beta-cyclodextrin 1:2.5 mol/mol complex in water-acetonitrile (1:1, v/v) (Solvent A) or in anhydrous acetonitrile (Solvent B), both containing 0.05 M HCl. In anhydrous acetonitrile, beta-cyclodextrin is insoluble and the included drug remains entrapped, allowing the free piroxicam determination, while with 50% of water, the complex is totally dissolved, allowing the determination of the total guest content. This method was validated for linearity, precision and accuracy. The presence of cyclodextrin does not influence the assays, but more than 0.5% of water in Solvent B significantly affects the determination of the free piroxicam content. In comparison with differential scanning calorimetry, both detectability and precision were improved. It is now possible to analyse complexes with an inclusion purity greater than 99%.
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Affiliation(s)
- Thierry Van Hees
- Department of Pharmaceutical Technology, Institute of Pharmacy, University of Liege, CHU, tour no. 4, Avenue de l'Hôpital, 1, Belgium.
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18
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Abstract
FTIR and FT-Raman spectroscopies were used to evaluate the mechanism of transformation of piroxicam into its different forms (alpha, beta, and monohydrate), depending on the environment. These vibrational techniques allowed us to identify the forms of piroxicam that crystallize from different solvents at different cooling rates and the conformation of the drug in some of its derivatives: piroxicam hydrochloride, piroxicam thallium and sodium salt hemihydrates, and piroxicam sodium salt. The usefulness of Raman spectroscopy in characterizing piroxicam:beta-cyclodextrin (PbetaCD) inclusion compounds was described. The Raman spectrum of 1:2 PbetaCD was discussed in comparison with that of the corresponding piroxicam sodium salt containing inclusion compound (1:2 PNabetaCD) in order to study the influence of the piroxicam derivative used on the structure of the inclusion compound. The Raman results showed that in both of the inclusion compounds the piroxicam mainly assumes the zwitterionic structure typical of a monohydrate; therefore, the kind of derivative used does not affect the conformation of the drug in its inclusion compound. The effect of the method of synthesis utilized (freeze-drying or freeze-thaw cycling) to obtain 1:2.5 PbetaCD was investigated. The inclusion compound obtained by freeze-thaw cycling proved to be more crystalline and to contain a higher amount of the beta form than the freeze-dried inclusion compound. Raman spectroscopy proved to be a useful technique for evaluating the effectiveness of the manufacturing process in relation to the pharmaceutical properties of the drug and to the nondestructive and noninvasive on-line quality control of the industrial products.
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Affiliation(s)
- P Taddei
- Dipartimento di Biochimica G. Moruzzi, Sezione di Chimica e Propedeutica Biochimica, University of Bologna, Via Belmeloro 8/2, 40126 Bologna, Italy.
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