Mucoadhesive Properties of Thiolated Pectin-Based Pellets Prepared by Extrusion-Spheronization Technique.

The aim of this study was to develop mucoadhesive pellets on a thiolated pectin base using the extrusion-spheronization technique. Thiolation of pectin was performed by esterification with thioglycolic acid. The molecular weight and thiol group content of the pectins were determined. Pellets containing pectin, microcrystalline cellulose, and ketoprofen were prepared and their mucoadhesive properties were evaluated through a wash-off test using porcine intestinal mucosa. The in vitro ketoprofen release was also evaluated. Thiolated pectin presented a thiol group content of 0.69 mmol/g. Thiolation caused a 13% increase in polymer molecular weight. Pellets containing thiolated pectin were still adhering to the intestinal mucosa after 480 min and showed a more gradual release of ketoprofen. Conversely, pellets prepared with nonthiolated pectin showed rapid disintegration and detached after only 15 min. It can be concluded that thiolated pectin-based pellets can be considered a potential platform for the development of mucoadhesive drug delivery systems for the oral route.

Development of a buccal mucoadhesive film for fast dissolution: mathematical rationale, production and physicochemical characterization.

The validity of a mathematical rationale for preparation of a fast-dissolving buccal mucoadhesive was tested. A buccal mucoadhesive biopolymeric formulation has been developed having pullulan as the main component. The formulation was duly evaluated physicochemically, via assays for intrinsic viscosity (resulting in 71.61 cm3 g(-1)), differential scanning calorimetry analysis (resulting in a Tg = 63 °C), thermogravimetric analysis (244-341 °C), moisture content determinations (14%, w/w), dissolution timeframe (41.6 s), mucoadhesion force (40 kg/cm2), scanning electron microscopy analyses (critical ray under 1.0 µm), mechanic strength (tensile strength = 58 N/mm2, deformation = 4.4%). The mucoadhesive formulation exhibited important characteristics for a drug carrier, that is, a 6 cm2 area, a fast dissolution timeframe, an adequate mucoadhesivity, resistance to both oxygen and water vapor penetration, increased viscosity in solution (ranging from 33.2 cm3/g to 71.61 cm3/g), easy molding, suitable water solubility and transparency.

Hydrophilic coating of mitotane-loaded lipid nanoparticles: preliminary studies for mucosal adhesion.

The aim of the present work was to load mitotane, an effective drug for adrenocortical carcinoma treatment, in solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC). The SLN and NLC were successfully prepared by high shear homogenization followed by hot high pressure homogenization. Formulations were composed of cetyl palmitate as the solid lipid for SLN, whereas for NLC PEGylated stearic acid was selected as solid lipid and medium chain triacylglycerols as the liquid lipid. Tween® 80 and Span® 85 were used as surfactants for all formulations. The particle size, zeta potential, polydispersity index (PI), encapsulation efficiency (EE), and loading capacity (LC) were evaluated. The SLN showed a mean particle size of 150 nm, PI of 0.20, and surface charge -10 mV, and the EE and LC could reach up to 92.26% and 0.92%, respectively. The NLC were obtained with a mean particle size of 250 nm, PI of 0.30, zeta potential -15 mV and 84.50% EE, and 0.84% LC, respectively. Hydrophilic coating of SLN with chitosan or benzalkonium chloride was effective in changing zeta potential from negative to positive values. The results suggest that mitotane was efficiently loaded in SLN and in NLC, being potential delivery systems for improving mitotane LC and controlled drug release.