rickets is a nutritional disorder that can develop if you do not get enough vitamin d calcium or phosphate rickets leads to poor functioning of a bone s growth plate growing edge softened and weakened bones stunted growth and in severe cases skeletal deformities
Hence, a 20-year period of the patent usually gives manufacturers a chance to recoup the cost of developing a new drug. When a drug patent expires, any pharmaceutical company can manufacture and sell the drug. A drug, which is produced and distributed without patent protection is called a generic drug.
In the United States, the life span of a patent depends on many factors, but once secured, a patent generally provides protection to its owner for a period of 20 years from the date the patent application was filed.