Objective: Propranolol Hydrochloride (PHCL) is used for the treatment of hypertension and angina pectoris; however it has two major problems; short biological halfâ€life and low bioavailability, so the aim of the present work was to develop PHCL mucoadhesive microsphere to prolong the residence time at the absorption site, therefore, increase the bioavailability.Methods: PHCL microspheres were prepared by ionotropic gelation method using nature polymers. Factorial design (33) was used to develop PHCL mucoadhesive microspheres, the independent factors used were polymer type (Sodium carboxymethyl cellulose (Na CMC), and Hydroxyl propyl methyl cellulose (HPMC), Carpobol 940), cross-linking type (calcium chloride, zinc chloride and barium chloride) and the concentration of Chitosan (0.5, 1, 1.5 %w/v). The developed microspheres were physicochemical characterized. The selected formula was selected for mucoadhesive test and in vivo study on human volunteers.Results: The results revealed that the PHCL mucoadhesive microspheres have good flowability, the mean particle sizes ranged from 541 to 815 µm and the entrapment efficiency ranged from 35.6% to 69.53%. The selected PHCL microspheres showed spherical particles with a rough surface and exhibited a slow release over 8h. The pharmacokinetic data of selected PHCL microspheres showed prolonged Tmax, decreased Cmax and AUC0–∞ value of 926.21±40.74ng. h/ml indicating improved relative bioavailability by144.93% compared with marketed tablets.Conclusion: PHCL microspheres were successfully prepared by ionic gelatin method that retards the release and enhances the oral bioavailability.Keywords: Propranolol HCL, Microspheres, Ionic gelation method, Chitosan, Relative bioavailabilit
