A single application of 30g clobetasone butyrate % ointment to eight patients resulted in a measurable rise in plasma clobetasone butyrate levels during the first three hours but then the levels gradually decreased. The maximum plasma level reached in the first three hours was /ml. This rise in levels was followed by a more gradual decline with plasma levels of clobetasone butyrate falling below /ml (the lower limit of the assay) after 72 hours. The normal diurnal variation in plasma cortisol levels was not affected by the application of clobetasone butyrate ointment.
Corticosteroids have been used as drug treatment for some time. Lewis Sarett of Merck & Co. was the first to synthesize cortisone, using a complicated 36-step process that started with deoxycholic acid, which was extracted from ox bile .  The low efficiency of converting deoxycholic acid into cortisone led to a cost of US $200 per gram. Russell Marker , at Syntex , discovered a much cheaper and more convenient starting material, diosgenin from wild Mexican yams . His conversion of diosgenin into progesterone by a four-step process now known as Marker degradation was an important step in mass production of all steroidal hormones, including cortisone and chemicals used in hormonal contraception .  In 1952, . Peterson and . Murray of Upjohn developed a process that used Rhizopus mold to oxidize progesterone into a compound that was readily converted to cortisone.  The ability to cheaply synthesize large quantities of cortisone from the diosgenin in yams resulted in a rapid drop in price to US $6 per gram, falling to $ per gram by 1980. Percy Julian's research also aided progress in the field.  The exact nature of cortisone's anti-inflammatory action remained a mystery for years after, however, until the leukocyte adhesion cascade and the role of phospholipase A2 in the production of prostaglandins and leukotrienes was fully understood in the early 1980s.
Shake the drops gently to be sure the medicine is well mixed. Tilt your head back slightly and pull down on your lower eyelid. Position the dropper above your eye. Look up and away from the dropper. Squeeze out a drop and close your eye. Apply gentle pressure to the inside corner of your eye (near your nose) for about 1 minute to prevent the liquid from draining down your tear duct. If you are using more than one drop in the same eye, repeat the process with about 5 minutes between drops. If you are using drops in both eyes, repeat the process in the other eye.