desirable to maintain a therapeutic concentration of this drug in the blood of patients that require propranolol suitable time delivery systems for oral medication for propranolol are twice a day or in the case of this drug even once a day since propranolol has a biological four to seven hour half life and does not require an extremely narrow therapeutic concentration range in the blood it may be possible to deliver propranolol on a once a day basis and still achieve adequate therapeutic levels in the blood of the patient throughout the entire time period in the following table there is presented a formulation that is suitable for the time release of propranolol for 24 hour therapeutic durations the above two components are mixed in methanol water 1 1 v v at from 5 to 10 polymer content this is used as a coating material to be applied to a tablet made from the propranolol containing tablet in an air phase coating apparatus the following table gives a listing of the composition of a suitable tablet to be coated for this polymer film coating the above tabular data shows the contents of a film coating and of a propranolol containing tablet to be coated the tablet data shown above is for a 100 mg propranolol tablet and would have a total mass of 227 mg since the surface to volume of a sphere changes with the square and cube of the radius respectively there will of.