Metabolism of propanoate begins with its conversion to propionyl coenzyme A (propionyl-CoA), the usual first step in the metabolism of carboxylic acids. Since propanoic acid has three carbons, propionyl-CoA can directly enter neither beta oxidation nor the citric acid cycles. In most vertebrates, propionyl-CoA is carboxylated to D-methylmalonyl-CoA, which is isomerised to L-methylmalonyl-CoA. A vitamin B 12 -dependent enzyme catalyzes rearrangement of L-methylmalonyl-CoA to succinyl-CoA, which is an intermediate of the citric acid cycle and can be readily incorporated there.
Beclometasone dipropionate was first patented in 1962 and used medically in 1972.  It was approved for medical use in the United States in 1976.  It is on the World Health Organization's List of Essential Medicines , the most effective and safe medicines needed in a health system .  The wholesale price in the developing world for an inhaler containing 200 doses of medication is about USD as of 2014.  In the United States it costs between 50 and 100 USD for a typical month supply of the inhaled form.