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Polymeric nanoparticle suspensions were prepared from Eudragit RS100® and RL100® polymer resins and loaded with flurbiprofen (FLU), with the aim at improving the availability of the drug at an intra-ocular level for the prevention of the myosis induced during extracapsular cataract surgery.Nanosuspensions were prepared by a quasi-emulsion solvent diffusion technique using different formulation parameters (drug-to-polymer ratio, initial polymer concentration, agitation speed, etc.). The resulting nanoparticles showed mean sizes around 100 nm and a fixed positive charge (ξ-potential around +40/+60 mV). Stability tests after mid-time storage (4°C or room temperature) or freeze-drying were carried out to optimise a possible final pharmaceutical preparation. In vitro, dissolution tests showed a controlled release profile of FLU from the nanoparticles.In vivo anti-inflammatory efficacy was assessed in the rabbit eye after induction of an ocular trauma (paracentesis). FLU-loaded nanosuspensions did not show toxicity on ocular tissues. Moreover, an inhibition of the miotic response to the surgical trauma comparable to a control eye-drop formulation was obtained, even though an actual lower concentration of free drug in the conjunctival sac was achieved from the nanoparticle system. Drug levels in the aqueous humour were also higher after application of the nanosuspensions. [Copyright &y& Elsevier]

Essential oils are recognized as valuable active pharmaceutical ingredients attributed to a set of biological properties, which include antibacterial, antifungal, antiviral, antioxidant, anticancer, immune-modulatory, analgesic and anti-inflammatory activities. Their use in pharmaceutics is however compromised by their limited water solubility and low physicochemical stability (i.e. volatility, oxidation). In order to overcome these limitations, we aimed to develop nanostructured lipid carriers (NLC) as delivery systems for Mediterranean essential oils, in particular Rosmarinus officinalis L., Lavandula x intermedia “Sumian”, Origanum vulgare subsp. hirtum and Thymus capitatus essential oils, selected on the basis of their antioxidant and anti-inflammatory activities. NLC composed of Softisan (as solid lipid) have been produced by phase inversion temperature (PIT) and high-pressure homogenization (HPH), using two different emulsifiers systems. Particles have been further characterized for their mean particle size, polydispersity, zeta potential, morphology and chemical interactions. Best NLC formulations were obtained with Kolliphor/Labrafil as surfactants, and using Rosmarinus , Lavandula and Origanum as essential oils (PDI between 0.126 and 0.141, Zave < 200 nm). Accelerated stability studies have also been carried out to estimate the effect of the production method and surfactant composition on the long-term stability of EOs-loaded NLC. In vitro biological cell viability and anti-inflammatory activities were evaluated in Raw 264.7 cells (macrophage cell line), while in vitro antioxidant activity was checked by DPPH assay. Lavandula and Rosmarinus NLC were shown to be the most biocompatible formulations up to a concentration of 0.1% (v/v), whereas they were able to induce a dose-dependent anti-inflammatory activity in the order Lavandula  >  Rosmarinus  ≥  Origanum . [ABSTRACT FROM AUTHOR]