Propranolol is a nonselective B-adrenergic blocker used in arrhythmia, hypertension, and angina pectoris. After iv and oral administration of propranolol it is completely metabolized to several metabolites and negligible amount is excreted unchanged in urine (<0.5%). If propranolol elimination rate constant after a single oral dose is 0.17 hr-1, what is the renal excretion rate constant of propranolol ?