The 1988 movie trailer included in the DVD incorrectly states that Barbara Hershey was an Academy Award nominee when the movie came out; Hershey was not an Oscar nominee until 1997 for The Portrait of a Lady (1996).
The song about Otto Titsling, the inventor of the brassiere, was first introduced by Bette Midler on a 1986 album called "Mud Will Be Flung Tonight." The story of Otto Titsling (i.e. "a two-tit sling") and Phillip de Brassiere (i.e. "fill up the brassiere") is an urban legend, created by British humorist Wallace Reyburn in his 1971 book, 'Bust Up: The Uplifting Tale of Otto Titzling'. In fact, the brassiere was developed by various French fashion designers from ladies' corsets of the 19th century. The term "brassiere" is derived from the French "braciere," a name for an armored military breastplate.
The Barbara Hershey screen test scenes where filmed on the Plaza Hotel lobby set of Big Business (1988). The scene where Hillary and C.C. are at the store where they have their big fight around the middle of the movie was also filmed on the same set (notice the carpet is the same).
The trivia items below may give away important plot points.
The disorder Barbara Hershey develops is known as, "Viral Cardiomyopathy". The most common cause of this disorder is infection from the, "Coxsackie B" virus, which drastically weakens the heart, eventually keeping it from pumping the sufficient amount of blood necessary to keep the patient alive. As depicted in the film, it truly is fatal in all reported cases.
The library where Barbara Hershey researches her disease in is called Dennison Library. It is located at Scripps College, a competitive women's liberal arts college in Claremont, California. The library was originally designed to be a chapel before becoming a library, which is why it has such a unique and beautiful look.