Rheological and thermo-mechanical properties of Sepifilm–Sepisperse water dispersions and films

Cespi, Marco; Bonacucina, Giulia; Casettari, Luca

doi:10.1016/j.tca.2013.01.020

Cited by 2 publications

(2 citation statements)

References 32 publications

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“…In addition, it influences the slope of G′ and G″ traces and the frequency value of cross-over points. Thus, to better analyze and compare the different mechanical spectra, the G′/ G″ curves were linearized using a log-log transformation and then fitted with a linear equation [23,24]. The calculated slopes represent the moduli time dependency (or frequency dependency).…”

Section: Resultsmentioning

confidence: 99%

Rheological characterization of polyvinyl caprolactam–polyvinyl acetate–polyethylene glycol graft copolymer (Soluplus®) water dispersions

et al. 2013

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Soluplus® is a graft copolymer, with PEG and vinylcaprolactam/vinyl acetate side chains, recently available as excipient used to promote fast drug release in pharmaceutical dosage forms and as solubility enhancer. Despite this copolymer is reported to be able to act as a thickening additive and even as gelling agent as a function of temperature, there is a lack of information about the physical–chemical properties of its water dispersions. Thus, the aim of this paper is to investigate the influence of Soluplus® concentration and experimental temperature on the modification of the rheological properties of Soluplus® water dispersions. The results clearly indicated the influence of both the studied parameters and of their interactions on the Soluplus® thickening ability. Although some systems appear gel by human perception at 37 °C, the mechanical spectra demonstrated the lack of the formation of a tridimensional network structure. Overall, in all the analyzed temperatures and concentrations, the systems always behave as a “rheological” dilute or semidilute polymer solution

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Section: Resultsmentioning

confidence: 99%

Rheological characterization of polyvinyl caprolactam–polyvinyl acetate–polyethylene glycol graft copolymer (Soluplus®) water dispersions

et al. 2013

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“…The reduction of Tg temperature suggests that these copolymers effectively possess a plasticizing effect. The films plasticization results comparable with those of the commercially “ready‐to‐use” hypromellose‐based films, where the reduction of Tg was approximately of 10–30°C with respect to the value of pure hypromellose films …”

Section: Resultsmentioning

confidence: 99%

Evaluation of methoxy polyethylene glycol‐polylactide diblock copolymers as additive in hypromellose film coating

Cespi

Casettari

Bonacucina

et al. 2013

Polymers for Advanced Techs

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This paper deals with a new application of diblock methoxy polyethylene glycol-polylactide block copolymers, a class of synthetic biomaterials largely studied in the pharmaceutical and biomedical fields owing to their favorable properties such as biocompatibility, biodegradability, low immunogenicity, and good mechanical properties. In this work, these materials were evaluated as additives for gastro-soluble pharmaceutical coating aimed to reduce film stiffness and water permeability. Two copolymers with different polylactide chain lengths were synthesized and characterized in term of molecular weight and solid-state properties. A series of free films with different hypromellose/copolymers ratio were prepared and characterized in terms of appearance, components miscibility, plasticity, and water vapor permeability. The obtained results demonstrate that copolymers effectively influence hypromellose film properties according to their concentration and molecular weight. Specifically, the addition of the copolymer with a molecular weight of 6.5kDa in a ratio hypromellose:polymer 5:1, allowed to obtain films with good appearance, improved plasticization, and water permeability properties. For higher molecular weight, copolymer or different ratios was not possible to observe the improvement of all the properties at the same time. The results also make possible to define the critical features to improve in order to use block copolymers as additive in hypromellose film coating. The availability of new water-soluble additives able to work as plasticizer and moisture sealer in polymeric films represents an important progress not only in the field of pharmaceutical coating but also in that of food coatings, as for example in the formulation of edible films

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Rheological and thermo-mechanical properties of Sepifilm–Sepisperse water dispersions and films

Cited by 2 publications

References 32 publications

Rheological characterization of polyvinyl caprolactam–polyvinyl acetate–polyethylene glycol graft copolymer (Soluplus®) water dispersions

Rheological characterization of polyvinyl caprolactam–polyvinyl acetate–polyethylene glycol graft copolymer (Soluplus®) water dispersions

Evaluation of methoxy polyethylene glycol‐polylactide diblock copolymers as additive in hypromellose film coating

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