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.
QNASL Nasal Aerosol is a pressurized, nonaqueous solution in a metered-dose aerosol device intended ONLY for intranasal use. It contains a solution of beclomethasone dipropionate in propellant HFA-134a (1,1,1,2-tetrafluoroethane) and dehydrated ethanol. QNASL 40 mcg Nasal Aerosol delivers 40 mcg of beclomethasone dipropionate from the nasal actuator and 50 mcg from the valve. QNASL 80 mcg Nasal Aerosol delivers 80 mcg of beclomethasone dipropionate from the nasal actuator and 100 mcg from the valve. Each strength delivers 59 mg of solution from the valve with each actuation. Each canister of QNASL 40 mcg or 80 mcg Nasal Aerosol, contains g of drug and excipients and each provides 120 actuations after priming. Additionally, QNASL 40 mcg Nasal Aerosol contains g of drug and excipients and provides 60 actuations after priming.
Subgroup analysis according to three possible sources of heterogeneity, participants, treatments and risk of bias was planned but not performed because there were insufficient studies for any comparison. The summary measure data were translated into absolute risk reductions (ARR) for a range of baseline risks for alkylating agents and cyclosporin. Adverse effects were tabulated and assessed with descriptive techniques for alkylating agents and cyclosporin. Adverse effects for other medications were listed in the text and where possible included in the meta-analyses.