It happened around 10:00pm at the CVS at Skippack and Dekalb Pike in Montgomery County.
Surveillance video captured a white male in his mid 20's with a handgun. The man displayed the gun and demanded narcotics.
Police say the suspect fled on foot after receiving an undetermined amount of drugs and cash.
He is described as a white male, mid 20's, approximately 5'6" tall and 190 pounds, wearing a light brown hat, long sleeved shirt, jeans and dark glasses.
Police are asking anyone with information to call Whitpain Township Detective Division at 610-279-9033.