Thermal stability of methacrylic acid copolymers of Eudragits L, S, and L30D and the acrylic acid polymer of carbopol

Lin, Shan‐Yang; Yu, Hui-Ling

doi:10.1002/(sici)1099-0518(19990701)37:13<2061::aid-pola20>3.0.co;2-y

Cited by 31 publications

(13 citation statements)

References 11 publications

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“…PMMA and Eudragits belong to a group of commercially available acrylic resins 18, 19. Acrylic resins are thermoplastic polymers used to produce paints, synthetic rubbers, and lightweight plastics.…”

Section: Introductionmentioning

confidence: 99%

Poly(ethylene glycol)/acrylic polymer blends for latent heat thermal energy storage

2006

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Section: Introductionmentioning

confidence: 99%

Poly(ethylene glycol)/acrylic polymer blends for latent heat thermal energy storage

2006

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“…The sample disc was previously equilibrated at the starting temperature (25°C) for ∼3 min and then heated to 200°C. The thermal‐responsive IR spectra were recorded with respect to this temperature 8–10. After the first heating process, the sample disc was cooled to room temperature in 15 min and its IR spectrum was again determined.…”

Section: Methodsmentioning

confidence: 99%

Solid-state trans–cis isomerization of captopril determined by thermal Fourier transform infrared (FT-IR) microspectroscopy

Wang

Lin

Chen

et al. 2001

Journal of Pharmaceutical Sciences

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“…The flow property of the extrudates was poor with very long residential time indicating the high melt viscosity and consequently the high shear forces generated inside the extruder that accelerated the degradation of Eudragit ® S100 and potential the CX. Lin and Yu (1999) reported using reflectance FT-IR/DSC microspectroscopy to examine the thermal stability of Eudragit ® S100 that the initial reaction temperature of a 6-membered ring of cyclic anhydride degradant in Eudragit ® S100 films can be very close to 180°C.…”

Section: Characterization Of Melt Extrudatesmentioning

confidence: 99%

The Use of Binary Polymeric Networks in Stabilizing Polyethylene Oxide Solid Dispersions

Jones

Tian

Shu

et al. 2016

Journal of Pharmaceutical Sciences

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The objective of this study was to investigate the role of amorphous domain of polyethylene oxide (PEO), a semicrystalline polymer, on the stability of drug/PEO solid dispersion. Molecular dispersion of drugs within hydrophilic low molecular weights PEOs (solid solution) has been demonstrated as a viable approach to enhance the dissolution properties and hence the oral bioavailability of poorly soluble drugs. In this system, the drug molecules are dissolved within the amorphous domain of the polymer and a miscible amorphous drug/polymer combination can result in a decrease of the polymer crystallinity, and hence increasing its amorphous fraction. This may result in increasing the drug solubility in the polymer hence affecting the stability of drug/polymer solid dispersion system. PEO is a highly crystallisable semi-crystalline polymer in natural and a rapid decrease in the amorphous fraction of the polymer may occur immediately after hot-melt extrusion resulting a forced migration of amorphous drug into nearby amorphous region. Thus, the actual concentrations of the drug within PEO solid dispersion were much higher than the concentration that we intended. Therefore, we are proposing a novel method of stabilising the amorphous drug/PEO solid dispersion by stabilising the amorphous region of PEO using another amorphous polymer. Inclusion of a miscible polymer that can increase the glass transition (Tg) of PEO (antiplasticization) or/and form strong inter-polymer interactions was used to enhance the stability of the amorphous PEO. In this study, the effects of inter-polymer interactions and miscibility between PEO and an amorphous polymer of high Tg, Eudragit ® S100, on the stability of the amorphous PEO and consequently the PEO/drug celecoxib (CX) solid dispersion was studied. Hot-melt extrusion (HME) was used to prepare different ratios of binary polymer blends of PEO/S100 (70/30, 50/50 and 30/70 w/w) and ternary solid dispersion systems containing pre-defined drug loading within the PEO/S100 polymer blends. Results from differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) suggested a great miscibility between PEO and S100 polymer blends particularly in the 50/50 ratio. After immediately HME, single Tg was observed in all ternary systems that increase with increasing S100 amount (antiplasticization). The completely absence of PXRD crystalline Bragg's peaks also suggested the full amorphous CX/polymer solid dispersion has been produced. Upon storage, CX crystallized rapidly from the CX/PEO (30/70) system within 3 days at 40°C and 75% RH, whereas it remained stable without crystallization up to 4 weeks within CX/(PEO/S100) 30/(50/50) system. Interestingly, both the stability of the amorphous PEO and CX were greater in the ternary system containing the polymer blend at 50/50 ratio than other systems. Despite of the lower Tg of 30/(50/50) system than 30/(30/70) one, the former was more stable. This indicates that the antiplasticization effects by Eudragit ® S100 were not the ...

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Thermal stability of methacrylic acid copolymers of Eudragits L, S, and L30D and the acrylic acid polymer of carbopol

Cited by 31 publications

References 11 publications

Poly(ethylene glycol)/acrylic polymer blends for latent heat thermal energy storage

Poly(ethylene glycol)/acrylic polymer blends for latent heat thermal energy storage

Solid-state trans–cis isomerization of captopril determined by thermal Fourier transform infrared (FT-IR) microspectroscopy

The Use of Binary Polymeric Networks in Stabilizing Polyethylene Oxide Solid Dispersions

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