Mepụta ụdị nke ahịrịokwu a dị mgbagwoju anya Nchebe patent Pfizer na Norvasc dịgidere ruo 2007.
N'ezie, nsụgharị dị mgbagwoju anya nke ahịrịokwu ahụ bụ "Pfizer's patent protection on Norvasc lasted until 2007, total patent expiration occurred later in 2007. "