Sustained release properties of the beads coated with the mixtures of propranolol hydrochloride and ethylcellulose

Abstract

Release characteristics of propranolol hydrochloride dispersed in ethylcellulose film coated on the surface of the beads using fluidized-bed technique were investigated. Size classified sucrose crystal and inert pellet were employed as coating cores. The influence of content and type of plasticizer, the volume of coating solution on drug release rate were studied. The hydrophobic plasticizer (glycerylmonostearate and castor oil) was found to retard drug release more than hydrophilic plasticizer (PEG 4000) When the thickness of drug dispersed film increased, the release of drug decreased. However, the release of the drug from the coated film was not prolonged enough to meet the requirement of sustained release product. Therefore, outercoating with only ethylcellulose film was used to reduce drug release rate as required. The outercoating could provide the release of propranolol hydrochloride in canpliance with the canpendial requirement. This process offered good reproducibility of drug release rate from the coated beads of different production lots.