From 1951 to 1974, inmates were paid to test a variety of substances that included deodorants and shampoos as well as radioactive, hallucinogenic and toxic materials on behalf of more than 30 pharmaceutical companies and several government agencies. In some experiments, prisoners were deliberately exposed to pathogens responsible for skin infections, including the herpes virus, staphylococcus bacteria and the athlete’s foot fungus, according to “Acres of Skin” (Routledge, 1998), a book by Allen M. Hornblum about the Holmesburg Prison research.

Though other universities and prisons also engaged in research, “you’d be hard pressed to find a prison system with so many protocols over so many years as Holmesburg,” Mr. Hornblum said in an interview Monday.

“He had a dozen or two experiments going at one time,” Mr. Hornblum said of Dr. Kligman. “He turned Holmesburg into the Kmart of human experimentation. It was a real industry.”

Dr. Kligman maintained that the public benefited greatly from the experiments, which besides Retin-A led to most of the treatments used today for poison ivy. He repeatedly said that the research was within the accepted norms of the time and that no prisoner suffered long-term harm, as far as he knew.

Many prisoners felt otherwise. In October 2000, nearly 300 former inmates sued the University of Pennsylvania, Dr. Kligman, Johnson & Johnson (the marketer of Retin-A) and others for injuries they said had resulted from the prison experiments. The suit was dismissed because the statute of limitations had expired.

Driven in part by abuses at Holmesburg, federal regulations were enacted in 1978, three years after the prison closed, to restrict medical studies in prisons. Today federal funds may be used only for tests that pose minimal risks to inmates — a safeguard that not only protects prisoners but also prevents them from participating in pharmaceutical or public health research that may help them.

Image Dr. Albert M. Kligman taught at the University of Pennsylvania. Credit... Salvatore C. Dimarco Jr. for The New York Times

“Holmesburg was an example of gross abuse, but there was such an overreaction to it that virtually all beneficial research stopped” in prisons, said Lawrence O. Gostin, a Georgetown University law professor, who in 2006 was the chairman of a federal advisory committee that recommended opening prisons to broader research. “We froze out high-quality science. That made Holmesburg horrible for two reasons.”