Locally used antimicrobials are rapidly cleared during the treatment of chronic periodontitis. The purpose behind this study was to prepare optimized ornidazole ethyl cellulose (EC) microparticles (MPs) with subsequent loading into chitosan strips formulation for local drug delivery. Three formulations of MPs were prepared using varying amount of EC and optimized for morphology and particle size, drug incorporation efficiency (IE) and loading capacity (LC), and in-vitro release. Chitosan carrying optimized ornidazole MPs strips then prepared using dispersion technique and characterized for surface pH and morphology, in-vitro and in-situ release, in-vitro and ex-vivo antimicrobial activity. The results were that the chitosan strips showed asymmetrical distribution of uniform shape holding ornidazole loaded EC containing MPs and great sustained release time. Moreover, the drug-loaded MPs having drug:polymer ratio 1:3 and films having 5% glycerol showed emphasize extended release. The excellent results of in-vitro and ex-vivo antimicrobial activity proved the stability of drug into the films. The prepared strips with assured sustained release should be a batter dosage form for enhanced treatment of periodontitis.