It took place around 8:40 p.m. Friday at the Rite Aid on the 1900 block of Fairmount Avenue.
Police say a 28-year-old employee attempted to stop the suspect for suspected shoplifting.
When the employee approach the suspect, police say he pulled out a pocketknife.
He then began chasing the employees, threatening them in order to flee the store.
Police say he fled with multiple bars of Dove soap.
The employees were not injured.
The suspect is described a black male, 45 years of age, 5'8, 220 pounds, bald with a beard, and was wearing a black hooded sweatshirt and gray sweatpants.
Anyone with information should call Central Detective Division at 215-686-3093/3094.