doctoralThesis
Nanotechnological delivery systems for the oral administration of active molecules: Polymeric microparticles and microemulsions applied to anti-inflammatory and anti-infectious drugs
Fecha
2013-04-05Registro en:
SILVA, Acarilia Eduardo da. Nanotechnological delivery systems for the oral administration of
active molecules: Polymeric microparticles and microemulsions applied to anti-inflammatory and anti-infectious drugs. 2013. 186 f. Tese (Doutorado em Ciências da Saúde) - Universidade Federal do Rio Grande do Norte, Natal, 2013.
Autor
Silva, Acarilia Eduardo da
Resumen
This thesis was devoted to the development of innovative oral delivery systems for two
different molecules. In the first part, microparticles (MPs) based on xylan and Eudragit® S-
100 were produced and used to encapsulate 5-aminosalicylic acid for colon delivery. Xylan
was extracted from corn cobs and characterized in terms of its physicochemical, rheological
and toxicological properties. The polymeric MPs were prepared by interfacial cross-linking
polymerization and spray-drying and characterized for their morphology, mean size and
distribution, thermal stability, crystallinity, entrapment efficiency and in vitro drug release.
MPs with suitable physical characteristics and satisfactory yields were prepared by both
methods, although the spray-dried systems showed higher thermal stability. In general, spraydried
MPs would be preferable systems due to their thermal stability and absence of toxic
agents used in their preparation. However, drug loading and release need to be optimized. In
the second part of this thesis, oil-in-water microemulsions (O/W MEs) based on mediumchain
triglycerides were formulated as drug carriers and solubility enhancers for amphotericin
B (AmB). Phase diagrams were constructed using surfactant blends with hydrophiliclipophilic
balance values between 9.7 and 14.4. The drug-free and drug-loaded MEs presented
spherical non-aggregated droplets around 80 and 120 nm, respectively, and a low
polydispersity index. The incorporation of AmB was high and depended on the volume
fraction of the disperse phase. These MEs did not reduce the viability of J774.A1
macrophage-like cells for concentrations up to 25 μg/mL of AmB. Therefore, O/W MEs
based on propylene glycol esters of caprylic acid may be considered as suitable delivery
systems for AmB