Loading...
2 results
Search Results
Now showing 1 - 2 of 2
- Engineering of konjac glucomannan into respirable microparticles for delivery of antitubercular drugsPublication . Guerreiro, Filipa; Swedrowska, Magda; Patel, Roshnee; Floréz- Fernández, Noelia; Torres, María Dolores; Rosa Da Costa, Ana M.; Forbes, Ben; Grenha, AnaFew medically-approved excipients are available for formulation strategies to endow microcarriers with improved performance in lung drug targeting. Konjac glucomannan (KGM) is a novel, biocompatible material, comprising mannose units potentially inducing macrophage uptake for the treatment of macrophage-mediated diseases. This work investigated spray-dried KGM microparticles as inhalable carriers of model antitubercular drugs, isoniazid (INH) and rifabutin (RFB). The polymer was characterised and different polymer/drug ratios tested in the production of microparticles for which respirability was assessed in vitro. The swelling of KGM microparticles and release of drugs in simulated lung fluid were characterised and the biodegradability in presence of beta-mannosidase, a lung hydrolase, determined. KGM microparticles were drug loaded with 66-91% association efficiency and had aerodynamic diameter around 3 mu m, which enables deep lung penetration. The microparticles swelled upon liquid contact by 40-50% but underwent size reduction (>62% in 90 min) in presence of beta-mannosidase, indicating biodegradability. Finally, drug release was tested showing slower release of RFB compared with INH but complete release of both within 24 h. This work identifies KGM as a biodegradable polymer of natural origin that can be engineered to encapsulate and release drugs in respirable microparticles with physical and chemical macrophage-targeting properties.
- Hydrothermal processing of laminaria ochroleuca for the production of crude extracts used to formulate polymeric nanoparticlesPublication . Flórez-Fernández, Noelia; Álvarez-Viñas, Milena; Guerreiro, Filipa; Torres, María Dolores; Grenha, Ana; Domínguez, HerminiaA green extraction process using only water was proposed for the simultaneous extraction of alginate and bioactive compounds from Laminaria ochroleuca. Operation was carried out during non-isothermal heating up to maximal temperatures over the range of 70 °C to 100 °C. Once separated, the alginate and the crude extract were characterised and the biological activities and cytotoxicity of the extracts was studied, the latter in intestinal epithelial cells. Those alginates obtained at 90 °C exhibited the highest extraction yields and viscoelastic features of the corresponding hydrogels. The obtained results show that the extracts obtained by non-isothermal extraction were suitable to formulate nanoparticles, which showed the smallest size (≈ 250-350 nm) when the higher content of fucoidan extract was present. Given the evidenced properties, the extracts may find an application in the formulation of nanoparticulate carriers for drug delivery.