SJP will be appearing as feminist author and activist Gloria Steinem in Lovelace, the story of 1970s porn star Linda Lovelace.
The film has already started shooting, with Amanda Seyfried in the title role.
Getting the story of Lovelace, who died 10 years ago, to the screen has not been easy. Lindsay Lohan was at one time tied to another project about the infamous porn star.
Demi Moore was rushed to the hospital Monday night after a 911 caller from her home reported that she'd gone into "convulsions" after she "smoked something."
That something, RadarOnline.com reported, is believed to be a synthetic drug called K2 Spice.
Moore has since been released from the hospital and has reportedly entered rehab.