Cora-Laó, Marianela

Profile Picture

Filters

20121
Reset filters

Settings

Citations

Publication Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    Publication
    Characterization of solid dispersions of hydroxypropyl cellulose films with griseofulvin via hot-melt extrusion
    (2012) Cora-Laó, Marianela; Acevedo Rullán, Aldo; College of Engineering; Rinaldi, Carlos; Mendez, Rafael; Department of Chemical Engineering; Ferrer, Mercedes
    Hot-melt extrusion has gained significance in the pharmaceutical industry to formulate solid dispersions. In a solid dispersion, poorly-water soluble drugs can be dispersed in an inert hydrophilic polymer matrix, improving the stability and bioavailability of the drug. In this work, solid dispersions of hydroxypropyl cellulose (HPC) and griseofulvin were formulated via this method and the effects of HPC molecular weight, type of plasticizer, griseofulvin concentration, and processing temperature on the thermal, mechanical and rheological properties was evaluated. Films showed Young’s moduli in the following ascending order: glycerol, d-dorbitol, and PEG, which shows a proportional relationship to plasticizer miscibility. On the other hand, griseofulvin loading has a plasticizing effect in Young’s moduli. Griseofulvin loading also showed a plasticizing effect in melting peak temperature, except at certain concentrations when glycerol and d-sorbitol are used as plasticizers. This deviation can be attributed to stronger intra molecular interactions of griseofulvin with glycerol and d-sorbitol as demonstrated by calculated strengths of interaction parameters. In addition, melt viscosity demonstrated that griseofulvin has a plasticizing effect in HPC, decreasing melt viscosity by one order of magnitude with the addition of 0.20 volume fraction. Once a plasticizer is added to the solid dispersion, griseofulvin has an antiplasticizing effect, i.e. melt viscosity increases. Flory-Huggins solubility parameters indicate partial miscibility, of lower molecular weight additives in HPC and, therefore, have better plasticizing effects, including griseofulvin. But once a third component, such as a plasticizer, is added to a solid dispersion the properties depend of the concentrations, miscibility, and molecular interactions of the specific components of the formulation. Calculation of the solubility and interaction parameters can be used as a priori method to screen for suitable solid dispersion formulations.