Purpose: To develop gastro-resistant multiparticles systems for mesalazine colon delivery capable to facilitate the dispersion in water and the intake by children.

Method: Mesalazine microparticles, containing stearic acid, carnauba wax and Eudragit L®, were obtained by spray-congealing. “Excipient microparticles” of mannitol/lecithin were prepared by spray-drying. Mesalazine lipid microparticles, non-agglomerating per se, were agglomerated by blending in turbula with mannitol/lecithin spray-dried microparticles in different ratio (2:1, 4:1, 6:1 and 8:1). The lipid microparticles and agglomerates were characterized by optical microscopy, Scanning Electron Microscopy, Differential Scanning Calorimetry (DSC) and X-ray Powder Diffraction (PXRD) and preliminary study of wettability. Gastro-resistance and drug release were evaluated by dissolution tests at variable pH (2h in HCl 0.1N and 6h in phosphate buffer pH 7.4).

Conclusion: Lipidic microparticles prepared by spray congealing are gastroresistant; their wettability can be increased by agglomeration with mannitol/lecithin microparticles. The agglomeration technology can make feasible the delivery of gastro-resistant system for extemporaneous oral use in small children.