Unlayered–Layered Crystal Transition in Recyclable Long-Spaced Aliphatic Polyesters

Background: Clarithromycin is widely used for infections of helicobacter pylori. Clarithromycin belongs to polymorphic drug. Crystalline state changes of clarithromycin in sustained release tablets were found. Objective: The aim of this study was to find the influential factor of the crystal transition of clarithromycin in preparation process of sustained-release tablets and to investigate the possible interactions between the clarithromycin and pharmaceutical excipients. Methods and Results: The crystal transition of active pharmaceuticals ingredients from form II to form I in portion in clarithromycin sustained release tablets were confirmed by x-ray powder diffraction. The techniques including differential scanning calorimetry and infrared spectroscopy, x-ray powder diffraction were used for assessing the compatibility between clarithromycin and several excipients as magnesium stearate, lactose, sodium carboxymethyl cellulose, polyvinyl-pyrrolidone K-30 and microcrystalline cellulose. All of these methods showed compatibilities between clarithromycin and the selected excipients. Alcohol prescription simulation was also done, which showed incompatibility between clarithromycin and concentration alcohol. Conclusion: It was confirmed that the reason for the incompatibility of clarithromycin with high concentration of alcohol was crystal transition.

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Heterogeneous mesoporous SBA-15 silica as catalyst towards the synthesis of various biodegradable aliphatic polyesters

Macromolecular Research ◽

10.1007/s13233-013-1101-y ◽

2013 ◽

Vol 21 (8) ◽

pp. 833-842 ◽

Cited By ~ 6

Author(s):

Sakthivel Gandhi ◽

Swaminathan Sethuraman ◽

Uma Maheswari Krishnan

Keyword(s):

Aliphatic Polyesters

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Shear-induced glass-to-crystal transition in anisotropic clay-like suspensions

Soft Matter ◽

10.1039/d0sm02081h ◽

2021 ◽

Author(s):

Vincent Labalette ◽

Alexis Praga ◽

Florent Girard ◽

Martine Meireles ◽

Yannick Hallez ◽

...

Keyword(s):

Stokesian Dynamics ◽

Crystal Transition

A new numerical framework based on Stokesian dynamics is used to study a shear-induced glass-to-crystal transition in suspensions of clay-like anisotropically charged platelets.

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The layered crystal structure of bis(theophyllinium) hexachloridostannate (IV), C14H18N8O8SnCl6

Zeitschrift für Kristallographie - New Crystal Structures ◽

10.1515/ncrs-2021-0185 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Guido J. Reiss ◽

Maik Wyshusek

Keyword(s):

Crystal Structure ◽

Layered Crystal ◽

Layered Crystal Structure

Abstract C14H18N8O8SnCl6, monoclinic, P21/n (no. 14), a = 8.1810(2) Å, b = 12.6195(3) Å, c = 11.3811(2) Å, β = 90.258(2)°, Z = 2, V = 1174.97(5) Å3, R gt(F) = 0.0266, wR ref = 0.0620, T = 290 K.

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Aliphatic polyesters. I. The degradation of poly(ϵ-caprolactone)in vivo

Journal of Applied Polymer Science ◽

10.1002/app.1981.070261124 ◽

1981 ◽

Vol 26 (11) ◽

pp. 3779-3787 ◽

Cited By ~ 475

Author(s):

C. G. Pitt ◽

F. I. Chasalow ◽

Y. M. Hibionada ◽

D. M. Klimas ◽

A. Schindler

Keyword(s):

Aliphatic Polyesters

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Design of 3D Additively Manufactured Hybrid Structures for Cranioplasty

Materials ◽

10.3390/ma14010181 ◽

2021 ◽

Vol 14 (1) ◽

pp. 181

Author(s):

Roberto De Santis ◽

Teresa Russo ◽

Julietta V. Rau ◽

Ida Papallo ◽

Massimo Martorelli ◽

...

Keyword(s):

Physical Models ◽

Cranial Bone ◽

Head Model ◽

Rigid Sphere ◽

Element Analysis ◽

Aliphatic Polyesters ◽

Hybrid Device ◽

Wide Range ◽

Hybrid Devices ◽

Technical Solutions

A wide range of materials has been considered to repair cranial defects. In the field of cranioplasty, poly(methyl methacrylate) (PMMA)-based bone cements and modifications through the inclusion of copper doped tricalcium phosphate (Cu-TCP) particles have been already investigated. On the other hand, aliphatic polyesters such as poly(ε-caprolactone) (PCL) and polylactic acid (PLA) have been frequently investigated to make scaffolds for cranial bone regeneration. Accordingly, the aim of the current research was to design and fabricate customized hybrid devices for the repair of large cranial defects integrating the reverse engineering approach with additive manufacturing, The hybrid device consisted of a 3D additive manufactured polyester porous structures infiltrated with PMMA/Cu-TCP (97.5/2.5 w/w) bone cement. Temperature profiles were first evaluated for 3D hybrid devices (PCL/PMMA, PLA/PMMA, PCL/PMMA/Cu-TCP and PLA/PMMA/Cu-TCP). Peak temperatures recorded for hybrid PCL/PMMA and PCL/PMMA/Cu-TCP were significantly lower than those found for the PLA-based ones. Virtual and physical models of customized devices for large cranial defect were developed to assess the feasibility of the proposed technical solutions. A theoretical analysis was preliminarily performed on the entire head model trying to simulate severe impact conditions for people with the customized hybrid device (PCL/PMMA/Cu-TCP) (i.e., a rigid sphere impacting the implant region of the head). Results from finite element analysis (FEA) provided information on the different components of the model.

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Crystal structure of oxybutynin hydrochloride hemihydrate, C22H32NO3Cl(H2O)0.5

Powder Diffraction ◽

10.1017/s0885715618000842 ◽

2019 ◽

Vol 34 (1) ◽

pp. 50-58

Author(s):

James A. Kaduk ◽

Nicholas C. Boaz ◽

Amy M. Gindhart ◽

Thomas N. Blanton

Keyword(s):

Crystal Structure ◽

Hydrogen Bonds ◽

Powder Diffraction ◽

Density Functional ◽

Hydroxyl Group ◽

Layered Crystal ◽

Powder Diffraction File ◽

X Ray ◽

Layered Crystal Structure ◽

Oxybutynin Hydrochloride

The crystal structure of oxybutynin hydrochloride hemihydrate has been solved and refined using synchrotron X-ray powder diffraction data, and optimized using density functional techniques. Oxybutynin hydrochloride hemihydrate crystallizes in space group I2/a (#15) with a = 14.57266(8), b = 8.18550(6), c = 37.16842(26) Å, β = 91.8708(4)°, V = 4421.25(7) Å3, and Z = 8. The compound exhibits X-ray-induced photoreduction of the triple bond. Prominent in the layered crystal structure is the N–H⋅⋅⋅Cl hydrogen bond between the cation and anion, as well as O–H⋅⋅⋅Cl hydrogen bonds from the water molecule and hydroxyl group of the oxybutynin cation. C–H⋅⋅⋅Cl hydrogen bonds also contribute to the crystal energy, and help determine the conformation of the cation. The powder pattern is included in the Powder Diffraction File™ as entry 00-068-1305.

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