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- Optimization of two biopolymer-based oral films for the delivery of bioactive moleculesPublication . Castro, Pedro M.; Fonte, Pedro; Oliveira, Ana; Madureira, Ana Raquel; Sarmento, Bruno; Pintado, Manuela E.An experimental design was established in order to optimize the mechanical properties of two oral film formulations intended for oral delivery of bioactive compounds. Carboxymethylcellulose (CMC) and gelatin type A (GelTA) were selected as polymeric matrix. Scanning electron microscopy revealed that caffeine crystals were homogeneously dispersed onto oral film matrix. Fourier-transform infrared analysis did not indicate formation of new chemical entities. USP modified dissolution assay revealed that GelTA was more effective in controlling caffeine release since maximum caffeine release (97.4%±0.95) after 20min. On the other hand, CMC is better indicated for immediate release since maximum caffeine release (81.1%±2.14) occurred after 4min. Simulation of gastrointestinal tract with ex vivo permeability assay was in accordance with USP dissolution assay (42.0%±7.79 and 15.3%±4.0 of caffeine released from CMC and GelTA oral films (OF), respectively, permeated porcine intestinal mucosa after 120min). CMCOF and GelTAOF optimized formulations represent two suitable oral delivery systems for immediate and controlled release, respectively.
- Oral films as breakthrough tools for oral delivery of proteins/peptidesPublication . Castro, Pedro M.; Fonte, Pedro; Sousa, Flávia; Madureira, Ana Raquel; Sarmento, Bruno; Pintado, Manuela E.Therapeutic proteins and peptides demonstrate unique, peerless, pharmacological characteristics such as high specificity to receptors and superior biological mimicking of physiological mechanisms, resulting in a better therapeutic index compared to conventional chemical-derived drugs. However, proteins also present inherent bioavailability limitations. Thus, this paper proposes several effective tools to improve protein/peptide drugs stability, permeability and pharmacokinetics with special emphasis on oral polymeric films as oral delivery platforms. Indeed, oral films present inherent characteristics that can greatly enhance biological performance of proteins and peptides and patient compliance along with other advantages that are critically discussed in this review. A rational choice of excipients addressed in and manufacture processes are also focused. In addition, possible toxicity issues to be overtaken and critical analysis regarding current market tendencies respecting oral films and protein/peptides along with future prospects are disclosed.
- Characterization of solid lipid nanoparticles produced with carnauba wax for rosmarinic acid oral deliveryPublication . Madureira, Ana Raquel; Campos, Débora A.; Fonte, Pedro; Nunes, Sara; Reis, Flávio; Gomes, Ana Maria; Sarmento, Bruno; Pintado, Maria ManuelaIn the last decade, research studies have increased on the development of delivery systems for polyphenols, for protection, improvement of stability and increase of their bioavailability. Rosmarinic acid is a polyphenol with described bioactivities, such as antioxidant, anti-mutagenic, anti-bacterial and anti-viral capabilities. Thus, the aim of this research work was to produce stable solid lipid nanoparticles (SLN) using carnauba wax as lipidic matrix, for delivery of rosmarinic acid, to be further incorporated into food matrices. Hence, different concentrations of wax (0.5, 1 and 1.5%, w/v) and percentages of surfactant (1, 2 and 3%, v/v) were tested. Physical properties, surface morphology and association efficiencies were studied at time of production and after 28 day at refrigerated storage. Thermal properties and the nature of the chemical interactions between the lipids waxes and rosmarinic acid were also evaluated. The particles showed range size between 35-927 nm and zeta potentials of ca. -38 to 40, showing high stability, with no risk of aggregation due to electric repulsion of SLN. High association efficiencies % (ca. 99%) were obtained. FTIR analyses proved the association of rosmarinic acid and lipidic matrix. The low lipid and high surfactant concentrations leads to small SLN. The surfactant, polysorbate 80 decreases the interfacial tension in the SLN surfaces, preventing aggregation, leading to the development of small particles. These properties were maintained throughout the 28 day of refrigerated storage, and no rosmarinic acid was released by the particles during refrigeration, indicating good compatibility between rosmarinic acid and the waxy core of SLN. The optimum range values to obtain the desirable features for incorporation in a functional food suggest formulations containing 1.0 and 1.5% (w/v) of lipid and 2% (v/v) of surfactant.
- Natural extracts into chitosan nanocarriers for rosmarinic acid drug deliveryPublication . Silva, Sara Baptista da; Amorim, Manuela; Fonte, Pedro; Madureira, Raquel; Ferreira, Domingos; Pintado, Manuela; Sarmento, BrunoContext: Nanotechnology can be applied to deliver and protect antioxidants in order to control the oxidative stress phenomena in several chronic pathologies. Chitosan (CS) nanoparticles are biodegradable carriers that may protect antioxidants with potent biological activity such as rosmarinic acid (RA) in Salvia officinalis (sage) and Satureja montana (savory) extracts for safe and innovative therapies. Objective: Development and characterization of CS nanoparticles as a stable and protective vehicle to deliver RA for medical applications using natural extracts as sage and savory. Materials and methods: Antioxidant-CS based nanoparticles were prepared by ionic gelation with sodium tripolyphosphate (TPP), at pH 5.8 with a mass ratio of 7:1 (CS:TPP), with a theoretical antioxidant-CS loading of 40-50%. The nanoparticles were then characterized by different methods such as photon correlation spectroscopy, laser Doppler anemometry, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR), high-performance liquid chromatographic (HPLC), association efficiency, and antioxidant activity. Results and discussion: Individual and small sizing nanoparticles, around 300 nm, were obtained. SEM confirmed smooth and spherical nanoparticles after freeze-drying. No chemical interactions were found between antioxidants and CS, after encapsulation, by DSC and FTIR. The association efficiency was 51.2% for RA (with 40% loading) and 96.1 and 98.2% for sage and savory nanoparticles, respectively (both with 50% loading). Antioxidant activity values were higher than 0.0348 eq [Asc. Ac.] g/L/g extract and 0.4251 μmol/eq Trolox/g extract. Conclusion: The extracts under study are promising vehicles for RA drug delivery in CS nanocarriers.