RESUMEN
A complex of low molecular weight chitosan (LMWC) with oleic acid and diclofenac potassium (DP) was prepared and dispersed in high concentrations of polysorbate 20, 60 and 80 in water to form a solution which releases its components slowly. The formed complex was characterized using different analytical methods. The size of the resulted nanoparticles and the effect of tweens on size were followed using dynamic light scattering (DLS). The release of DP from this delivery system was monitored by altering the molecular weight of chitosan and the type and concentration of the polysorbates used. The most suitable preparation consisted of DP, LMWC 13 kDa, and oleic acid. This was dispersed in 5% Tween 80 and the release was followed by the adaptation of USP II apparatus using a cellophane bag. This preparation offers a release of up to 24 h.