A unique patent window
When a company develops a drug, it is patented in two stages – the original patent and a secondary patent. When the original patent expires, the secondary succeeds, often protecting microscopic “fingerprints” of various crystalline forms from being copied.
Today no conventional developing methods are able to produce copies of drugs that are out of scope for the secondary patent protection. As a result of that the original company is able to continue to market it unthreatened by the generic market.