7 documents found, page 1 of 1
Influence of polymer processing technique on long term degradation of poly(ε-ca...
Natu, Mădălina V.; Sousa, Hermínio C. de; Gil, M. H.Films, fibers, sponges and disks, based on poly(ε-caprolactone), PCL were prepared using solvent-casting, electrospinning, supercritical fluid processing and melt-compression, respectively. The extent of degradation was determined by measuring the change in morphology, crystallinity and molecular weight (MW). The influence of processing method, MW and drug presence on degradation rate was also evaluated. The di...
A poly(ε-caprolactone) device for sustained release of an anti-glaucoma drug
Natu, Mădălina V.; Gaspar, Manuel N.; Ribeiro, Carlos A. Fontes; Correia, Ilídio J.; Silva, Daniela; Sousa, Hermínio C. de; Gil, M. H.Implantable dorzolamide-loaded discs were prepared by blending poly(ε-caprolactone), PCL, with poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide), Lu. By blending, crystallinity, water uptake and mass loss were modified relative to the pure polymers. Burst was diminished by coating the discs with a PCL shell. All samples presented burst release except PCL-coated samples that showed controlled r...
In vitro and in vivo evaluation of an intraocular implant for glaucoma treatment
Natu, Mădălina V.; Gaspar, Manuel N.; Ribeiro, Carlos A. Fontes; Cabrita, António M.; Sousa, Hermínio C. de; Gil, M. H.Implantable disks for glaucoma treatment were prepared by blending poly(ɛ-caprolactone), PCL, poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide) and dorzolamide. Their in vivo performance was assessed by their capacity to decrease intraocular pressure (IOP) in normotensive and hypertensive eyes. Drug mapping showed that release was complete from blend disks and the low molecular weight (MW) PCL...
Electrospun Drug-Eluting Fibers for Biomedical Applications
Natu, Mădălina V.; Sousa, Hermínio C. de; Gil, Maria H.Electrospinning is a simple and versatile method to produce fibers using charged polymer solutions. As drug delivery systems, electrospun fibers are an excellent choice because of easy drug entrapment, high surface area, morphology control and biomimetic characteristics. Various drugs and biomolecules can be easily encapsulated inside or on fiber surface either during electrospinning or through post-processing ...
Effects of drug solubility, state and loading on controlled release in bicompon...
Natu, Mădălina V.; Sousa, Hermínio C. de; Gil, M. H.Bicomponent fibers of two semi-crystalline (co)polymers, poly(ɛ-caprolactone), and poly(oxyethylene-b-oxypropylene-b-oxyethylene), were obtained by electrospinning. Acetazolamide and timolol maleate were loaded in the fibers in different concentrations (below and above the drug solubility limit in polymer) in order to determine the effect of drug solubility in polymer, drug state, drug loading and fiber composi...
Supercritical solvent impregnation of poly(ɛ-caprolactone)/poly(oxyethylene-b-o...
Natu, Mădălina V.; Gil, M. H.; Sousa, Hermínio C. dePoly(ɛ-caprolactone) blends were successfully impregnated with timolol maleate, an anti-glaucoma drug, using a supercritical solvent impregnation (SSI) technique. Supercritical fluid impregnation efficiency results suggested that the best impregnating conditions were obtained when a cosolvent was used and when specific drug–polymer interactions occurred as a consequence of different chemical structures due to p...
Controlled release gelatin hydrogels and lyophilisates with potential applicati...
Natu, Mădălina V.; Sardinha, José P.; Correia, Ilídio J.; Gil, M. H.Hydrogels and lyophilisates were obtained by chemical crosslinking of gelatin using N-hydroxysuccinimide and N, N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride. The systems were characterized with respect to the degree of crosslinking, morphology, water uptake, in vitro drug release and biocompatibility studies. Pilocarpine hydrochloride, a drug for the treatment of glaucoma, was loaded by soaking ...