Assessement of anti-inflammatory properties of microspheres prepared with chitosan and 5-amino salicylic acid over inflamed Caco-2 cells

Microspheres based on the interaction between 5-amino salicylic acid (5-ASA) and chitosan were designed as a new colonic delivery system. Microspheres were prepared by a spray drying technique and characterised by physical properties, morphology and drug dissolution characteristics. Effects of the microspheres over inflamed Caco-2 cells were also evaluated, by determining cell viability and expression of mRNA levels of biomarkers involved in the pathogenesis of Inflammatory Bowel Diseases (IBD) (IL-1β and IL-8). Results showed that chitosan improved dissolution properties of 5-ASA. The amount of free drug released over 120 min did not exceed 9 mg/cm2, while microspheres showed a high dissolution rate reaching approximately 50 mg/cm2 of drug released. Contact of inflamed cells with free 5-ASA reduced mRNA levels of IL-1β and IL-8. Microspheres did not show cytotoxic activity and maintained ILs levels observed in non-inflamed cells, mimicking the anti-inflammatory effect of 5-ASA alone.