The Fulton County Medical Examiner's office in Georgia said Brown, 22, had no previously unknown medical conditions that would have contributed to her death.
It also said it has issued subpoenas to help gather documentary information on her death, and would conduct additional tests that are expected to take several weeks.
Brown, the only child of Houston and R&B singer Bobby Brown, died at an Atlanta-area hospice where her family had placed her a month ago after giving up hope she would recover.
