1
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Zhang J, Liu M, Xu M, Chen Z, Peng X, Yang Q, Cai T, Zeng Z. Discovery of a new polymorph of clotrimazole through melt crystallization: Understanding nucleation and growth kinetics. J Chem Phys 2023; 158:034503. [PMID: 36681648 DOI: 10.1063/5.0130600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Clotrimazole (CMZ) is a classical antifungal drug for studying crystallization. In this study, a new CMZ polymorph (Form 2) was discovered during the process of nucleation and growth rate determination in the melt. High-quality single crystals were grown from melt microdroplets to determine the crystal structure by x-ray diffraction. Form 2 is metastable and exhibits a disordered structure. The crystal nucleation and growth kinetics of the two CMZ polymorphs were systematically measured. Form 2 nucleates and grows faster than the existing form (Form 1). The maximum nucleation rate of Forms 1 and 2 was observed at 50 °C (1.07 Tg). The summary of the maximum nucleation rate temperature of CMZ and the other six organic compounds indicates that nucleation near Tg in the supercooled liquid is a useful approach to discovering new polymorphs. This study is relevant for the discovering new drug polymorphs through an understanding of nucleation and growth kinetics during melt crystallization.
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Affiliation(s)
- Jie Zhang
- College of Biological and Chemical Engineering, Changsha University, Changsha 410022, China
| | - Minzhuo Liu
- College of Biological and Chemical Engineering, Changsha University, Changsha 410022, China
| | - Meixia Xu
- Yantai Key Laboratory of Nanomedicine and Advanced Preparations, Yantai Institute of Materia Medica, Shandong 264000, China
| | - Zhiguo Chen
- College of Biological and Chemical Engineering, Changsha University, Changsha 410022, China
| | - Xucong Peng
- College of Biological and Chemical Engineering, Changsha University, Changsha 410022, China
| | - Qiusheng Yang
- College of Biological and Chemical Engineering, Changsha University, Changsha 410022, China
| | - Ting Cai
- Department of Pharmaceutics, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Zhihong Zeng
- College of Biological and Chemical Engineering, Changsha University, Changsha 410022, China
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2
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Grimling B, Karolewicz B, Nawrot U, Włodarczyk K, Górniak A. Physicochemical and Antifungal Properties of Clotrimazole in Combination with High-Molecular Weight Chitosan as a Multifunctional Excipient. Mar Drugs 2020; 18:E591. [PMID: 33255899 PMCID: PMC7760713 DOI: 10.3390/md18120591] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 11/19/2020] [Accepted: 11/24/2020] [Indexed: 12/16/2022] Open
Abstract
Chitosans represent a group of multifunctional drug excipients. Here, we aimed to estimate the impact of high-molecular weight chitosan on the physicochemical properties of clotrimazole-chitosan solid mixtures (CL-CH), prepared by grinding and kneading methods. We characterised these formulas by infrared spectroscopy, differential scanning calorimetry, and powder X-ray diffractometry, and performed in vitro clotrimazole dissolution tests. Additionally, we examined the antifungal activity of clotrimazole-chitosan mixtures against clinical Candida isolates under neutral and acid conditions. The synergistic effect of clotrimazole and chitosan S combinations was observed in tests carried out at pH 4 on Candida glabrata strains. The inhibition of C. glabrata growth reached at least 90%, regardless of the drug/excipient weight ratio, and even at half of the minimal inhibitory concentrations of clotrimazole. Our results demonstrate that clotrimazole and high-molecular weight chitosan could be an effective combination in a topical antifungal formulation, as chitosan acts synergistically with clotrimazole against non-albicans candida strains.
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Affiliation(s)
- Bożena Grimling
- Department of Drug Form Technology, Wroclaw Medical University, Borowska 211 A, 50-556 Wroclaw, Poland;
| | - Bożena Karolewicz
- Department of Drug Form Technology, Wroclaw Medical University, Borowska 211 A, 50-556 Wroclaw, Poland;
| | - Urszula Nawrot
- Department of Pharmaceutical Microbiology and Parasitology, Wroclaw Medical University, Borowska 211 A, 50-556 Wroclaw, Poland; (U.N.); (K.W.)
| | - Katarzyna Włodarczyk
- Department of Pharmaceutical Microbiology and Parasitology, Wroclaw Medical University, Borowska 211 A, 50-556 Wroclaw, Poland; (U.N.); (K.W.)
| | - Agata Górniak
- Laboratory of Elemental Analysis and Structural Research, Wroclaw Medical University, Borowska 211 A, 50-556 Wroclaw, Poland;
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3
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Probing the Molecular-Level Interactions in an Active Pharmaceutical Ingredient (API) - Polymer Dispersion and the Resulting Impact on Drug Product Formulation. Pharm Res 2020; 37:94. [PMID: 32405662 DOI: 10.1007/s11095-020-02813-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Accepted: 04/02/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE An investigation of underlying mechanisms of API-polymer interaction patterns has the potential to provide valuable insights for selecting appropriate formulations with superior physical stability and processability. MATERIALS AND METHODS In this study, copovidone was used as a polymeric carrier for several model compounds including clotrimazole, nifedipine, and posaconazole. The varied chemical structures conferred the ability for the model compounds to form distinct interactions with copovidone. Rheology and nuclear magnetic resonance (NMR) were combined to investigate the molecular pattern and relative strength of active pharmaceutical ingredient (API)-polymer interactions. In addition, the impact of the interactions on formulation processability via hot melt extrusion (HME) and physical stability were evaluated. RESULTS The rheological response of an API-polymer system was found to be highly sensitive to API-polymer interaction, depending both on API chemistry and API-polymer miscibility. In the systems studied, dispersed API induced a stronger plasticizer effect on the polymer matrix compared to crystalline/aggregated API. Correspondingly, the processing torque via HME showed a proportional relationship with the maximum complex viscosity of the API-polymer system. In order to quantitatively evaluate the relative strength of the API-polymer interaction, homogeneously dispersed API-polymer amorphous samples were prepared by HME at an elevated temperature. DSC, XRD, and rheology were employed to confirm the amorphous integrity and homogeneity of the resultant extrudates. Subsequently, the homogeneously dispersed API-polymer amorphous dispersions were interrogated by rheology and NMR to provide a qualitative and quantitative assessment of the nature of the API-polymer interaction, both macroscopically and microscopically. Rheological master curves of frequency sweeps of the extrudates exhibited a strong dependence on the API chemistry and revealed a rank ordering of the relative strength of API-copovidone interactions, in the order of posaconazole > nifedipine > clotrimazole. NMR data provided the means to precisely map the API-polymer interaction pattern and identify the specific sites of interaction from a molecular perspective. Finally, the impact of API-polymer interactions on the physical stability of the resultant extrudates was studied. CONCLUSION Qualitative and quantitative evaluation of the relative strength of the API-polymer interaction was successfully accomplished by utilizing combined rheology and NMR. Graphical Abstract.
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4
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Influence of Glass Forming Ability on the Physical Stability of Supersaturated Amorphous Solid Dispersions. J Pharm Sci 2019; 108:2561-2569. [DOI: 10.1016/j.xphs.2019.02.028] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 02/05/2019] [Accepted: 02/19/2019] [Indexed: 02/05/2023]
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5
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Balachandar S, Sethuram M, Dhandapani M. Functional insights of a molecular complex pyrazolium 3,5-dinitrobenzoate:3,5-dinitrobenzoic acid on infectious agents and ctDNA - A comparative biological screening and complementary theoretical calculations. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2019; 196:111497. [PMID: 31154276 DOI: 10.1016/j.jphotobiol.2019.04.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 02/25/2019] [Accepted: 04/15/2019] [Indexed: 11/29/2022]
Abstract
Systematic identification and quantification of active radical sites in a small molecule, pyrazolium 3,5-dinitrobenzoate:3,5-dinitrobenzoic acid as well as in the stable free radical (DPPH•) were carried out by Fukui functions calculation using DFT functional with B3LYP/6-311++G(d,p) level of basis set. Bioactive Lewis acid-base compound, pyrazolium 3,5-dinitrobenzoate:3,5-dinitrobenzoic acid (PDNB:DNBA) has been synthesized and crystallized by slow evaporation - solution method at 30 °C. Various functional groups and the structural arrangements were ascertained from spectral and XRD analyses, respectively. UV-vis spectral analysis was used to find out the stability of the anticipated drug for about 60 min using methanol as a solvent. Stabilization of the compound was linked to the presence of enormous N-H…O, O-H…O and C-H…O hydrogen bonding interactions identified through Hirshfeld surface analysis. Chemical stability and reactivity of the drug were validated from theoretical optimization and HOMO-LUMO analysis. Active nucleophilic, electrophilic and radical sites of PDNB:DNBA were also identified from molecular electrostatic potential analysis. Inhibition of growth of pathogens in screening experiments by the proposed drug attests its suitability in biological applications. Antioxidant activity of the compound, PDNB:DNBA, endorses its aptness for scavenging reactive radicals. Fluorimetry experiments confirm hyperchromism in DNA binding analysis proving groove mode of binding. Molecular docking explored the various modes of intermolecular interactions of the drug with microbes as well as DNA.
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Affiliation(s)
- S Balachandar
- Post Graduate and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641020, Tamil Nadu, India
| | - M Sethuram
- Department of Chemical Engineering, Sethu Institute of Technology, Virudhunagar 626 115, Tamil Nadu, India
| | - M Dhandapani
- Post Graduate and Research Department of Chemistry, Sri Ramakrishna Mission Vidyalaya College of Arts and Science, Coimbatore 641020, Tamil Nadu, India.
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6
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Sheeja Mol GP, Aruldhas D, Hubert Joe I, Balachandran S, Ronaldo Anuf A, George J, Nadh AG. Structural activity, fungicidal activity and molecular dynamics simulation of certain triphenyl methyl imidazole derivatives by experimental and computational spectroscopic techniques. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 212:105-120. [PMID: 30616164 DOI: 10.1016/j.saa.2018.12.047] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 12/21/2018] [Accepted: 12/26/2018] [Indexed: 06/09/2023]
Abstract
The main objective of the study is to analyze the structural behaviour and fungicidal activity of clotrimazole by experimental and theoretical spectroscopic techniques. Its computational results are correlated with three triphenyl imidazole derivative compounds. The clotrimazole-water complexes formed by hydrogen bonding interactions are investigated at the B3LYP/6-311G(d,p) level. The distributions of the vibrational bands are carried out with the help of normal coordinate analysis (NCA). Hirshfeld surface analysis of clotrimazole is done and the obtained finger print plots reveal the interactions within the compound. The stability of the compounds in water has been investigated by using molecular dynamics simulation (MDS). Molecular docking is done on the compounds in comparison with the native ligand (Lanosterol 14α-demethylase) and standard drug (fluconazole) to study the hydrogen bond energy interaction. The antifungal activity of clotrimazole is analyzed by using two fungal pathogens.
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Affiliation(s)
- G P Sheeja Mol
- Manonmaniam Sundaranar University, Abishekapatti, Tirunelveli 627 012, Tamil Nadu, India; Department of Physics & Research Centre, Nesamony Memorial Christian College, Marthandam 629165, Tamil Nadu, India
| | - D Aruldhas
- Department of Physics & Research Centre, Nesamony Memorial Christian College, Marthandam 629165, Tamil Nadu, India.
| | - I Hubert Joe
- Centre for Molecular and Biophysics Research, Department of Physics, Mar Ivanios College, Thiruvananthapuram 695015, Kerala, India
| | | | - A Ronaldo Anuf
- Department of Biotechnology, Kamaraj College of Engineering and Technology, Virudhunagar 626001, Tamilnadu, India
| | - Jesby George
- Department of Physics, Bishop Moore College, Mavelikara, Alappuzha, Kerala 690110, India
| | - Anuroopa G Nadh
- Department of Computational Biology & Bioinformatics, University of Kerala, Kariavattom, Kerala 695581, India
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7
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Onawole AT, Popoola SA, Saleh TA, Al-Saadi AA. Silver-loaded graphene as an effective SERS substrate for clotrimazole detection: DFT and spectroscopic studies. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2018; 201:354-361. [PMID: 29763829 DOI: 10.1016/j.saa.2018.05.018] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Revised: 04/19/2018] [Accepted: 05/05/2018] [Indexed: 06/08/2023]
Abstract
Vibrational infrared, Raman and surface-enhanced Raman scattering (SERS) spectra of clotrimazole (CTZ) were documented and evaluated. Density-functional theory, B3LYP/6-311++G(d,p), approach was implemented to identify the possible conformations, develop the electrostatic potential map, evaluate frontier molecular orbitals and calculate the vibrational spectra of the target compound. The silver-loaded graphene was shown to be an effective SERS substrate for CTZ trace detection. The SERS spectrum showed two enhanced bands at 670 cm-1 and 700 cm-1 which confirmed the absorption of the silver substrate through chlorine and nitrogen atoms. A detection limit as low as 5 nM could be reached with a determination coefficient of 0.9988 using the band at 670 cm-1. The protein-ligand interaction with Secreted Aspartic Proteinase 2 (SAP2) of C. albicans showed that the four stable forms of CTZ maintain a free energy of binding of 6-7 kcal/mol, which could give insights into the mode of action in treating Candidiasis.
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Affiliation(s)
- Abdulmujeeb T Onawole
- Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
| | - Saheed A Popoola
- Department of Chemistry, Islamic University of Madinah, Saudi Arabia
| | - Tawfik A Saleh
- Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
| | - Abdulaziz A Al-Saadi
- Department of Chemistry, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia.
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8
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Christian P, Ehmann H, Coclite AM, Werzer O. Polymer Encapsulation of an Amorphous Pharmaceutical by initiated Chemical Vapor Deposition for Enhanced Stability. ACS APPLIED MATERIALS & INTERFACES 2016; 8:21177-84. [PMID: 27467099 PMCID: PMC4999961 DOI: 10.1021/acsami.6b06015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Accepted: 07/28/2016] [Indexed: 05/22/2023]
Abstract
The usage of amorphous solids in practical applications, such as in medication, is commonly limited by the poor long-term stability of this state, because unwanted crystalline transitions occur. In this study, three different polymeric coatings are investigated for their ability to stabilize amorphous films of the model drug clotrimazole and to protect against thermally induced transitions. For this, drop cast films of clotrimazole are encapsulated by initiated chemical vapor deposition (iCVD), using perfluorodecyl acrylate (PFDA), hydroxyethyl methacrylate (HEMA), and methacrylic acid (MAA). The iCVD technique operates under solvent-free conditions at low temperatures, thus leaving the solid state of the encapsulated layer unaffected. Optical microscopy and X-ray diffraction data reveal that at ambient conditions of about 22 °C, any of these iCVD layers extends the lifetime of the amorphous state significantly. At higher temperatures (50 or 70 °C), the p-PFDA coating is unable to provide protection, while the p-HEMA and p-MAA strongly reduce the crystallization rate. Furthermore, p-HEMA and p-MAA selectively facilitate a preferential alignment of clotrimazole and, interestingly, even suppress crystallization upon a temporary, rapid temperature increase (3 °C/min, up to 150 °C). The results of this study demonstrate how a polymeric coating, synthesized directly on top of an amorphous phase, can act as a stabilizing agent against crystalline transitions, which makes this approach interesting for a variety of applications.
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Affiliation(s)
- Paul Christian
- Institute of Solid State Physics, NAWI Graz, Graz University of Technology, 8010 Graz, Austria
| | - Heike
M.A. Ehmann
- Institute of Pharmaceutical Science, Department of Pharmaceutical
Technology, University of Graz, 8010 Graz, Austria
| | - Anna Maria Coclite
- Institute of Solid State Physics, NAWI Graz, Graz University of Technology, 8010 Graz, Austria
| | - Oliver Werzer
- Institute of Pharmaceutical Science, Department of Pharmaceutical
Technology, University of Graz, 8010 Graz, Austria
- E-mail:
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9
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Simpson PV, Nagel C, Bruhn H, Schatzschneider U. Antibacterial and Antiparasitic Activity of Manganese(I) Tricarbonyl Complexes with Ketoconazole, Miconazole, and Clotrimazole Ligands. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00458] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Peter V. Simpson
- Institut
für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Christoph Nagel
- Institut
für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
| | - Heike Bruhn
- Institut
für Molekulare Infektionsbiologie, Julius-Maximilians-Universität Würzburg, Josef-Schneider-Strasse 2/D15, D-97080 Würzburg, Germany
| | - Ulrich Schatzschneider
- Institut
für Anorganische Chemie, Julius-Maximilians-Universität Würzburg, Am Hubland, D-97074 Würzburg, Germany
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10
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Crowley PD, Gallagher HC. Clotrimazole as a pharmaceutical: past, present and future. J Appl Microbiol 2014; 117:611-7. [PMID: 24863842 DOI: 10.1111/jam.12554] [Citation(s) in RCA: 92] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 04/29/2014] [Accepted: 05/21/2014] [Indexed: 11/29/2022]
Abstract
Clotrimazole is a broad-spectrum antimycotic drug mainly used for the treatment of Candida albicans and other fungal infections. A synthetic, azole antimycotic, clotrimazole is widely used as a topical treatment for tinea pedis (athlete's foot), as well as vulvovaginal and oropharyngeal candidiasis. It displays fungistatic antimycotic activity by targeting the biosynthesis of ergosterol, thereby inhibiting fungal growth. As well as its antimycotic activity, clotrimazole has become a drug of interest against several other diseases such as sickle cell disease, malaria and some cancers. It has also been combined with other molecules, such as the metals, to produce clotrimazole complexes that show improved pharmacological efficacy. Moreover, several new, modified-release pharmaceutical formulations are also undergoing development. Clotrimazole is a very well-tolerated product with few side effects, although there is some drug resistance appearing among immunocompromised patients. Here, we review the pharmaceutical chemistry, application and pharmacology of clotrimazole and discuss future prospects for its further development as a chemotherapeutic agent.
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Affiliation(s)
- P D Crowley
- School of Medicine and Medical Science, Conway Institute, University College Dublin, Belfield, Dublin, Ireland
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11
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Ehmann HA, Zimmer A, Roblegg E, Werzer O. Morphologies in Solvent-Annealed Clotrimazole Thin Films Explained by Hansen-Solubility Parameters. CRYSTAL GROWTH & DESIGN 2014; 14:1386-1391. [PMID: 24624042 PMCID: PMC3948153 DOI: 10.1021/cg401859p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 01/17/2014] [Indexed: 05/11/2023]
Abstract
The induction of different crystal morphologies is of crucial importance for many applications. In this work, the preparation of various crystal morphologies within clotrimazole films on glass substrates is demonstrated. Amorphous clotrimazole thin films were transformed via vapor annealing into crystalline structures; highly monodisperse/multidisperse crystallites, spherulite, or dendritic structures were obtained as the solvent was exchanged. X-ray diffraction experiments reveal that the same polymorph is present for all samples but with varying texture. The achieved morphologies are explained in terms of Hansen-solubility parameters and vapor pressures; thus, the different morphologies and crystal orientations can be explained by solvent-solid interaction strengths within the thin film samples.
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Affiliation(s)
- Heike
M. A. Ehmann
- Institute
of Pharmaceutical Sciences, Department of Pharmaceutical Technology, Karl-Franzens University Graz, 8010 Graz, Austria
| | - Andreas Zimmer
- Institute
of Pharmaceutical Sciences, Department of Pharmaceutical Technology, Karl-Franzens University Graz, 8010 Graz, Austria
| | - Eva Roblegg
- Institute
of Pharmaceutical Sciences, Department of Pharmaceutical Technology, Karl-Franzens University Graz, 8010 Graz, Austria
- Research
Center Pharmaceutical Engineering GmbH, 8010 Graz, Austria
| | - Oliver Werzer
- Institute
of Pharmaceutical Sciences, Department of Pharmaceutical Technology, Karl-Franzens University Graz, 8010 Graz, Austria
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Benmore CJ, Weber J, Tailor AN, Cherry BR, Yarger JL, Mou Q, Weber W, Neuefeind J, Byrn SR. Structural Characterization and Aging of Glassy Pharmaceuticals made Using Acoustic Levitation. J Pharm Sci 2013; 102:1290-300. [DOI: 10.1002/jps.23464] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 12/20/2012] [Accepted: 01/11/2013] [Indexed: 11/09/2022]
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13
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Ozel Güven O, Erdoğan T, Coles SJ, Hökelek T. 1-{2-Phenyl-2-[4-(trifluoro-meth-yl)-benzyl-oxy]eth-yl}-1H-benzimidazole. Acta Crystallogr Sect E Struct Rep Online 2008; 64:o1655-6. [PMID: 21203341 PMCID: PMC2962243 DOI: 10.1107/s1600536808024033] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2008] [Accepted: 07/29/2008] [Indexed: 05/26/2023]
Abstract
The asymmetric unit of the crystal structure of the title compound, C23H19F3N2O, contains two independent molecules. In the two molecules the planar benzimidazole ring systems are oriented with respect to the phenyl/trifluoromethylbenzene rings at dihedral angles of 9.62 (6)/78.63 (7) and 2.53 (8)/83.83 (9)°. In the crystal structure, intermolecular C—H⋯N hydrogen bonds link the molecules into R22(6) dimers. The molecules are elongated along [001] and stacked along the b axis.
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Ozel Güven O, Erdoğan T, Coles SJ, Hökelek T. 1-[2-(3,4-Dichloro-benz-yloxy)-2-phenyl-ethyl]-1H-benzimidazole. Acta Crystallogr Sect E Struct Rep Online 2008; 64:o1588-9. [PMID: 21203286 PMCID: PMC2962124 DOI: 10.1107/s1600536808022629] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2008] [Accepted: 07/18/2008] [Indexed: 11/18/2022]
Abstract
In the molecule of the title compound, C22H18Cl2N2O, the planar benzimidazole ring system is oriented with respect to the phenyl and dichlorobenzene rings at dihedral angles of 12.73 (3) and 36.57 (4)°, respectively. The dihedral angle between the dichlorobenzene and phenyl rings is 29.95 (6)°. There are C—H⋯π contacts between the benzimidazole and dichlorobenzene rings, between the benzimidazole and phenyl rings, and between a methylene group and the dichlorobenzene ring.
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15
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Ozel Güven O, Erdoğan T, Coles SJ, Hökelek T. 1-[2-(4-Fluoro-benz-yloxy)-2-phenyl-ethyl]-1H-benzimidazole. Acta Crystallogr Sect E Struct Rep Online 2008; 64:o1496-7. [PMID: 21203208 PMCID: PMC2962126 DOI: 10.1107/s1600536808021326] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Accepted: 07/09/2008] [Indexed: 11/24/2022]
Abstract
The asymmetric unit of the title compound, C22H19FN2O, contains two independent molecules. The planar benzimidazole ring systems are oriented with respect to the phenyl/fluorobenzene rings at dihedral angles of 31.10 (4)/45.17 (5) and 45.52 (5)/68.63 (5)°, respectively, for the two molecules. In the crystal structure, intermolecular C—H⋯N and intermolecular C—H⋯N and C—H⋯F hydrogen bonds link the molecules into a three-dimensional network. There are C—H⋯π contacts between the benzimidazole and fluorobenzene rings and a π–π contact between the benzimidazole and phenyl ring systems [centroid–centroid distance = 4.575 (1) Å].
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16
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Özel Güven Ö, Erdoğan T, Coles SJ, Hökelek T. 1-[2-(2,6-Dichloro-benz-yloxy)-2-(2-fur-yl)eth-yl]-1H-benzimidazole. Acta Crystallogr Sect E Struct Rep Online 2008; 64:o1437. [PMID: 21203152 PMCID: PMC2962068 DOI: 10.1107/s1600536808020758] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Accepted: 07/04/2008] [Indexed: 11/10/2022]
Abstract
In the mol-ecule of the title compound, C(20)H(16)Cl(2)N(2)O(2), the planar benzimidazole ring system is oriented with respect to the furan and dichloro-benzene rings at dihedral angles of 53.39 (6) and 31.04 (5)°, respectively. In the crystal structure, inter-molecular C-H⋯Cl hydrogen bonds link the mol-ecules into centrosymmetric R(2) (2)(8) dimers. These dimers are connected via a C-H⋯π contact between the benzimidazole and the furan rings, and π-π contacts between the benz-imidazole and dichloro-benzene ring systems [centroid-centroid distances = 3.505 (1), 3.567 (1), 3.505 (1) and 3.567 (1) Å].
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Affiliation(s)
- Özden Özel Güven
- Department of Chemistry, Zonguldak Karaelmas University, 67100 Zonguldak, Turkey
| | - Taner Erdoğan
- Department of Chemistry, Zonguldak Karaelmas University, 67100 Zonguldak, Turkey
| | - Simon J. Coles
- Department of Chemistry, Southampton University, Southampton SO17 1BJ, England
| | - Tuncer Hökelek
- Department of Physics, Hacettepe University, 06800 Beytepe, Ankara, Turkey
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Wulff H, Miller MJ, Hansel W, Grissmer S, Cahalan MD, Chandy KG. Design of a potent and selective inhibitor of the intermediate-conductance Ca2+-activated K+ channel, IKCa1: a potential immunosuppressant. Proc Natl Acad Sci U S A 2000; 97:8151-6. [PMID: 10884437 PMCID: PMC16685 DOI: 10.1073/pnas.97.14.8151] [Citation(s) in RCA: 488] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The antimycotic clotrimazole, a potent inhibitor of the intermediate-conductance calcium-activated K(+) channel, IKCa1, is in clinical trials for the treatment of sickle cell disease and diarrhea and is effective in ameliorating the symptoms of rheumatoid arthritis. However, inhibition of cytochrome P450 enzymes by clotrimazole limits its therapeutic value. We have used a rational design strategy to develop a clotrimazole analog that selectively inhibits IKCa1 without blocking cytochrome P450 enzymes. A screen of 83 triarylmethanes revealed the pharmacophore for channel block to be different from that required for cytochrome P450 inhibition. The "IKCa1-pharmacophore" consists of a (2-halogenophenyl)diphenylmethane moiety substituted by an unsubstituted polar pi-electron-rich heterocycle (pyrazole or tetrazole) or a -CN group, whereas cytochrome P450 inhibition absolutely requires the imidazole ring. A series of pyrazoles, acetonitriles, and tetrazoles were synthesized and found to selectively block IKCa1. TRAM-34 (1-[(2-chlorophenyl)diphenylmethyl]-1H-pyrazole) inhibits the cloned and the native IKCa1 channel in human T lymphocytes with a K(d) of 20-25 nM and is 200- to 1,500-fold selective over other ion channels. Using TRAM-34, we show that blocking IKCa1 in human lymphocytes, in the absence of P450-inhibition, results in suppression of mitogen-stimulated [(3)H]thymidine incorporation of preactivated lymphocytes with EC(50)-values of 100 nM-1 microM depending on the donor. Combinations of TRAM-34 and cyclosporin A are more effective in suppressing lymphocyte mitogenesis than either compound alone. Our studies suggest that TRAM-34 and related compounds may hold therapeutic promise as immunosuppressants.
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Affiliation(s)
- H Wulff
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA.
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