Diclofenac

Research on the occurrence and seasonal monitoring of pharmaceutically active compounds (PhACs) in estuarine and coastal waters has intensified recently. However, few studies have been conducted with PhACs flowing into the marine waters of South America (such as Brazil). Against this backdrop, the aims of this study were: (i) evaluate, for the first time, the seasonal occurrence throughout a year and the potential ecological risks of ten selected PhACs in marine bathing waters from Santos Bay, São Paulo, Brazil (a tropical low-wave energy semi-closed bay); and (ii) develop a list of high-priority PhACs for the monitoring based on "occurrence, persistence, bioaccumulation, and toxicity" criteria (OPBT). Four water sampling campaigns were carried out throughout the four seasons of the year. The results showed that: (i) ten PhACs (namely, caffeine/CAF (87.20-567.23 ng/L); carbamazepine/CAR [below the limit of quantification ( ACE > DIC and CAR to algae, crustaceans, and fishes; (iv) Finally, regarding the OPBT ranking, the DIC was the highest-priority PhAC in Santos Bay, followed by: ORP > LOS > CIT > CAR > FUR > ATE > CAF > ACE > ENA.

When placed in the eye, contact lenses (CLs) disturb the tear fluid and affect the natural tribological behaviour of the eye. The disruption in the contact mechanics between the ocular tissues can increase frictional shear stress and ocular dryness, causing discomfort. Ultimately, continuous CLs wear can trigger inflammation which is particularly critical for people suffering from dry eye. In this work, a double strategy was followed to obtain therapeutic daily disposable CLs for dry eye: a hydroxyethyl methacrylate (HEMA) based hydrogel was coated with two natural polysaccharides, chitosan (CHI) and hyaluronic acid (HA) and posteriorly loaded with an anti-inflammatory drug (diclofenac, DCF). Material sterilisation was carried out by high hydrostatic pressure (HHP) combined with moderate temperature. The friction coefficient (μ) was determined in the presence of different tear biomolecules (cholesterol, lysozyme and albumin) using a nanotribometer. Drug release experiments were performed in static and in hydrodynamic conditions. The material was extensively characterised, regarding surface morphology/topography, optical properties, water content and swelling behaviour, wettability, ionic and oxygen permeability and mechanical properties. It was found that the coating did not impair the physico-chemical properties relevant for the material's application in CLs. Besides, it also ensured a sustained release of DCF for 24 h in tests performed in hydrodynamic conditions that simulate those found in the eye, increasing significantly the amount of drug released. It reduced friction, improving the lubrication ability of the hydrogel, and presented antibacterial properties against S. aureus, P. aeruginosa and B. Cereus. The coated samples did not reveal any signs of cytotoxicity or potential eye irritation. Overall, the coating of the hydrogel may be useful to produce daily CLs able to alleviate dry eye symptoms and the discomfort of CLs wearers.