Study of poly(ethylene oxide)/Carbopol blends through thermal analysis and infrared spectroscopy

Κanis, Luiz Alberto; Viel, Fabı́ola C; Crespo, Janaína da Silva; Bertolino, José Roberto; Pires, Alfredo T. N.; Soldi, Valdir

doi:10.1016/s0032-3861(99)00520-0

Cited by 53 publications

(33 citation statements)

References 27 publications

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“…During the first heating scan, water was eliminated (data not reported). In the second heating scan, the HEC Tg was observed around 70°C (17) and the Carbopol Tg was recorded around 130°C (18,19). These values were kept even in the physical blend and in the tablets without alterations in agreement with the results obtained from the X-ray analysis.…”

Section: Chemical Interaction Studiessupporting

confidence: 84%

Influence of Compression Force on The Behavior of Mucoadhesive Buccal Tablets

et al. 2008

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Abstract. The purpose of this research was to study the compression force influence on polymers, tablet behavior and drug release rate. Several tablet batches were produced by varying the compression force and by using hydroxyethyl cellulose (HEC) and Carbopol 940 in the 1:1 ratio as matrix forming polymers. All batches were characterized by DSC and X-ray analyses and in terms of swelling, ex vivo and in vivo mucoadhesive time, ex vivo mucoadhesion force, and in vitro and in vivo release. No significant excipient-excipient or excipient-drug interactions were observed in any of the batches. All the tablets hydrated quickly and their high hydration percentage showed that the compression forces used did not remarkably affect the water penetration and the polymeric chain stretching. Mucoadhesion performances and drug release were mainly influenced by compression force; its increase produced higher ex vivo and in vivo mucoadhesion and the in vitro and in vivo drug releases were seen to decrease with the increase of the compression force. However tablets fabricated by using the lowest compression force showed the best in vivo mucoadhesive time and hydrated faster when compared to the others. Tablets 4 and 5, prepared with the highest forces, caused pain during in vivo application and gave rise to irritation needing to be detached by the volunteers while tablet 1, prepared with the lowest force, gave the best results because it was able to produce the highest drug salivary concentration and no pain. All tablets exhibited an anomalous release mechanism.

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Section: Chemical Interaction Studiessupporting

confidence: 84%

Influence of Compression Force on The Behavior of Mucoadhesive Buccal Tablets

et al. 2008

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“…Ketorolac tromethamine showed a long and sharp characteristic endothermic peak at 1701C due to its phase transition. DSC thermogram of Carbopol s 934 showed endotherms between 50-1001C corresponding to the evaporation of moisture content and a poor resolved change in the base line of Carbopol s 934 at 129-1391C, as previously reported [Kanis et al, 2000]. Additional phase transition at lower temperatures, detected by DSC, may be related to the residual solvents that act as plasticizers but evaporate easily when temperature increases; the polymer then showed the characteristic phase transition at 1331C.…”

Section: Drug-excipient Compatibility Studiessupporting

confidence: 78%

Sustained ophthalmic in situ gel of ketorolac tromethamine: rheology and in vivo studies

Manjappa¹,

Nanjwade²,

Manvi³

et al. 2009

Drug Development Research

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Most ocular diseases are treated with topical eye drops. The poor bioavailability and therapeutic response exhibited by these conventional eye drops due to rapid precorneal elimination of the drug may be overcome by the use of in situ gelling systems that are instilled as drops into the eye and undergo a sol-to-gel transition in the cul-de-sac. The present work describes the formulation and evaluation of an ophthalmic delivery system of the nonsteroidal anti-inflammatory drug (NSAID), ketorolac tromethamine, based on the concept of pH-triggered in situ gelation. Polyacrylic acid (Carbopol s 934) was used as the gelling agent in combination with hydroxypropylmethylcellulose (Methocel E15LV), which acted as a viscosity enhancer. The prepared formulations were characterized for clarity, pH, drug content, rheology, and in vivo drug release. Clarity, pH, and drug content of the developed formulations were found to be satisfactory. The developed formulation showed pseudo-plastic rheology. The formulation with benzalkonium chloride and edetate disodium improved the rate of corneal absorption but not the extent. The developed formulation is a viable alternative to conventional eye drops by virtue of its ability to enhance bioavailability through its longer precorneal residence time and ability to sustain drug release. Also importantly is the ease of instillation afforded and decreased frequency of instillation resulting in better patient acceptance. Drug Dev Res 70 : 417-424, 2009.

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“…11,12 Information about molecular structure of complex mixtures can be obtained from Fourier transform infrared (FTIR) spectroscopic analysis. 13,14 The ease of sample preparation and operation, and nondestructive nature of analyses make FTIR attractive as a characterization technique to analyze gel formulations.…”

Section: Introductionmentioning

confidence: 99%

Fourier transform infrared spectroscopy for the analysis of neutralizer-carbomer and surfactant-carbomer interactions in aqueous, hydroalcoholic, and anhydrous gel formulations

Islam

Rodrı́guez-Hornedo

Ciotti

et al. 2004

AAPS J

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The objective of the present study is to evaluate the polymersurfactant and polymer-neutralizer interactions in topical aqueous, anhydrous, and hydroalcoholic gel formulations using Fourier transform infrared (FTIR) spectroscopy. The gels were prepared by dispersing Carbomer (Carbopol 980) in water and ethanol for aqueous and anhydrous systems, respectively. Glycerol and propylene glycol were also added to ensure that the compositions of gels closely resembled those used in typical topical gel formulations. Comparisons of the spectra of Carbopol dispersions in aqueous, anhydrous, and hydroalcoholic systems, performed for the first time, show Carbopol-neutralizer and Carbopol-surfactant interactions vary depending on the nature of the solvents used for gel formation. Analysis of the spectra of aqueous gel formulations indicates significant presence of ionized carboxyl groups only at higher pH (~8.0). Drying of the aqueous gels causes a shift in the carbonyl stretch band toward higher energy, suggesting changes in polymer-neutralizer interaction. Anhydrous gels exhibit 2 different carbonyl stretch bands: the one at ~1653 cm -1 is related to the carboxyl group that is hydrogen bonded and is akin to hydrous gels; the second one at ~1717 cm -1 is indicative of free carbonyl groups. The carbonyl bands of dried gels appear at different energy levels than the solvated gels. This shift resulting from solvent evaporation, reported for the first time, indicates changes in hydrogen bond characteristics. The results show that FTIR can be a good technique compared with other more time-consuming means of analysis for topical formulations.

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Study of poly(ethylene oxide)/Carbopol blends through thermal analysis and infrared spectroscopy

Cited by 53 publications

References 27 publications

Influence of Compression Force on The Behavior of Mucoadhesive Buccal Tablets

Influence of Compression Force on The Behavior of Mucoadhesive Buccal Tablets

Sustained ophthalmic in situ gel of ketorolac tromethamine: rheology and in vivo studies

Fourier transform infrared spectroscopy for the analysis of neutralizer-carbomer and surfactant-carbomer interactions in aqueous, hydroalcoholic, and anhydrous gel formulations

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