text: The distribution half-life of drospirenone is about 1.6 to 2 hours. The apparent volume of distribution of drospirenone is approximately 4 L/kg. The plasma protein binding of drospirenone is 95 to 97%. It is bound to albumin and 3 to 5% circulates freely or unbound. Drospirenone has no affinity for sex hormone-binding globulin (SHBG) or corticosteroid-binding globulin (CBG), and hence is not bound by these plasma proteins in the circulation.