An official website of the United States government
The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.
The site is secure.
The https:// ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.
Porter CJ, Charman WN.Porter CJ, et al. Among authors: charman wn.Adv Drug Deliv Rev. 2001 Aug 23;50(1-2):61-80. doi: 10.1016/s0169-409x(01)00151-x.Adv Drug Deliv Rev. 2001.PMID: 11489334Review.