Characterization of the copolymer poly(ethyleneglycol-g-vinylalcohol) as a potential carrier in the formulation of solid dispersions

Comparison Between Hot-Melt Extrusion and Spray-Drying for Manufacturing Solid Dispersions of the Graft Copolymer of Ethylene Glycol and Vinylalcohol

“…Previous experiments with plasticizers showed that depending on the type and concentration of the plasticizers, mixing occurred with one or two of the amorphous fractions of EG/VA (9). The present MDSC results show that only the first glass transition temperature shifts to higher temperatures as a function of the miconazole content, proving that miconazole only mixes with the PEG fraction of the copolymer and not with the PVA fraction after spraydrying.…”

“…Spray-drying resulted in amorphization of the PVA fraction, while hot-melt extrusion increased the crystallinity of the same fraction. Interestingly, tests with commonly used plasticizers like diethyl phthalate, low-molecular-weight PEG or propyleneglycol revealed that, depending upon both type and concentration of the plasticizer, mixing with only one or both amorphous domains of the copolymer resulted (9). This finding suggests that drug molecules may also mix with one or both amorphous fractions of EV/GA.…”

“…This is a combination of an enthalpy recovery endotherm that accompanies the glass transition of the PVA fraction (indicated with an asterisk in Fig. 3) and the evaporation of residual solvent (9). From a concentration of 12% w/w of miconazole there is a small endothermic peak visible on top of the broad endothermic signal, pointing to the presence of a crystalline drug phase.…”

“…A thorough characterization of this copolymer showed that it consists of two semi-crystalline fractions corresponding to the polyethylene glycol (PEG) fraction and the polyvinylalcohol (PVA) fraction (9). The PEG fraction shows a glass transition temperature at −57°C and a melting transition at 15°C; the PVA fraction shows a glass transition temperature around 45°C and a melting transition at 212°C.…”

Prilling of fatty acids as a continuous process for the development of controlled release multiparticulate dosage forms

“…The need for alternative excipients that allow for continuously producing solid dispersions to improve the dissolution of poorly water soluble drugs or to create sustained release dosage forms has been reported by different authors [1][2][3][4]. The application of oral sustained release formulations has improved patient compliance due to a lower dosing frequency and a reduced incidence of adverse side effects [5].…”