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.
It means only that the drug has been tested to assure its safety and potency for at least two years. In fact, a drug may be potent for 10 years or more but still have an expiration date that is only two or three years.