Effects of drug solubility, state and loading on controlled release in bicomponent electrospun fibers

Abstract

Bicomponent fibers of two semi-crystalline (co)polymers, poly(ε-caprolactone), PCL and poly(oxyethylene-b-oxypropylene-b-oxyethylene), Lu 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 composition on fiber morphology, drug distribution and release kinetics. The high loadings fibers (with drug in crystalline form) showed higher burst and faster release than low drug content fibers, indicating the release was more sustained when the drug was encapsulated inside the fibers, in amorphous form. Moreover, timolol maleate was released faster than acetazolamide, indicating that drug solubility in polymer influences the partition of drug between polymer and elution medium, while fiber composition also controlled drug release. At low loadings, total release was not achieved (cumulative release percentages smaller than 100 %), suggesting that drug remained trapped in the fibers. The modeling of release data implied a three stage release mechanism: a dissolution stage, a desorption and subsequent diffusion through water filled pores, followed by polymer degradation control.

Antidepressant effects of curcumin and HU-211 coencapsulated solid lipid nanoparticles against corticosterone-induced cellular and animal models of major depression

“…Abbreviations: cur/slNs-hU-211, curcumin and hU-211 coencapsulated solid lipid nanoparticles; hU-211, dexanabinol; slNs, solid lipid nanoparticles; cur/slNs, curloaded slNs; cur, curcumin. 36 thus leading to a sustained release, which is in accordance with our in vitro release assay results. Dynamic light scattering study showed that the hydrodynamic size of Cur/SLNs-HU-211 was 58.77±1.7 nm ( Figure 1E).…”

Intracellular uptake of etoposide-loaded solid lipid nanoparticles induces an enhancing inhibitory effect on gastric cancer through mitochondria-mediated apoptosis pathway

“…However, the amorphous or disordered-crystalline phase of the drug can allow for easy diffusion through the SLNs, leading to a sustained release of the encapsulated drug. 36,42,43 Figure 3 presents the photographs of free VP16, plain SLNs, and VP16-SLNs in PBS (0.01 M, pH 7.4), which were recorded after standing for 10 minutes, 3 hours, and 6 hours. It can be seen that both plain SLNs and VP16-SLNs dispersed stably in PBS, and little sedimentation of the particles was observed after standing for 6 hours.…”

Electrospun diclofenac sodium loaded Eudragit® L 100-55 nanofibers for colon-targeted drug delivery

“…highly distributed in the filament-forming polymer matrix (Ribeiro et al, 2005;Sawicka et al, 2005;Thakur et al, 2008;Yang et al, 2008). By exploiting nanofiber properties (such as small diameter, large surface area, high porosity, and assembling randomly in a non-woven mat with a continuous three-dimensional web structure), the functions of the incorporated materials can potentially be improved and may even gain enhanced functions due to nanoeffects (Sill and von Recum, 2008;Greiner and Wendorff, 2007;Rutledge and Fridrikh, 2007;Lu et al, 2009;Natu et al, 2010). Another strategy for enhancing function is to treat nanofibers after preparation by processes such as cross-linking and coating (Ding et al, 2005;Sell et al, 2008).…”