Formulation and evaluation of oil entrapped gastroretentive floating gel beads of loratadine
A gastro retentive controlled release system of loratadine was formulated to increase the residence time in stomach and to modulate the release behaviour of the drug. Oil entrapped floating microbeads prepared by the emulsion gelation method were optimized by 23 factorial design and a polymer ratio of 2.5:1.5 (pectin/sodium alginate) by mass, 15% (m/V) of oil (mineral oil or castor oil) and 0.45 mol L-1 calcium chloride solution as the optimized processing conditions for the desired buoyancy and physical stability. In vitro drug release in the fed state conditions demonstrated sustained release of loratadine for 8 h, which best fitted the Peppas model with n < 0.45. The ethyl cellulose coating on microbeads optimized by 22 factorial design resulted in a controlled release formulation of loratadine that provided zero-order release for 8 h.