The capsule returned to Earth at 11:47 am (1547 GMT) southwest of the Mexican state of Baja California with more than 3,000 pounds (1,360 kilograms) of cargo.
"Information from this investigation serves as a proxy for understanding how the human body changes in space, and how those changes may affect later generations", the Japanese science team says in a fact sheet on the experiment.
When it arrived at the station July 20, Dragon delivered the first of two worldwide docking adapters (IDAs) in its external cargo hold, or "trunk". The IDAs will be used for the future arrivals of Boeing and SpaceX commercial crew spacecraft in development under NASA's Commercial Crew Program. A cardiac cell experiment would like to analyze the impacts of outer space conditions to heart cells in a cellular level.
The second adapter is being built and will be delivered on a future Dragon cargo resupply mission, NASA said. The vessel returned to Earth with more than 3,000 lbs.
The cargo also contains research work from Mouse Epigenetics was also included, which was to throw light on the change in DNA of mouse's offspring after its one month stay in Space.
On board were 12 mice which travelled up into low-Earth orbit with the Dragon capsule a month ago.
Also returning are samples from the Multi-Omics experiment. The cells will help researchers better understand how microgravity affects the human heart.
Dragon is now the only space station resupply spacecraft able to return a significant amount of cargo to Earth. The Dragon began this particular journey July 18 at Cape Canaveral, Florida.
SpaceX is the only space station shipper capable of returning items for analysis back to Earth. The space station has been occupied continuously since November 2000.