Neither party disclosed the value of the transaction, El Nuevo Dia newspaper said.
The US giant announced in May 2010 that it would be closing two of its five factories in Puerto Rico, including the 130,000 sq. meter facility in the San Juan suburb of Caguas.
“The sale of the facility in Caguas is a positive result for our colleagues, the Caguas community and for Pfizer,” one of the US firm’s vice presidents, John Kelly, said.
Neolpharma plans to retain 130 of the plant’s existing staff and to hire another 60 people on a temporary basis, Kelly said.
The Mexican company employs around 1,500 people overall and produces painkillers, anti-cancer drugs and medications for ailments of the heart and central nervous system.
The acquisition in Caguas marks Neolpharma’s first manufacturing venture on US soil.
Pfizer’s planned plant closings represent the loss of some 1,500 jobs in Puerto Rico, which has been mired in recession since 2007 and has a double-digit unemployment rate.
The US company will continue to produce Advil and cholesterol drug Lipitor, among other medications, at three other facilities in Puerto Rico.