To cite an article from the 2000 AAPS PharmSci Supplement:

Authors Title Journal Supplement. Year; Volume (Issue) Available from: URL.

For example:

J. Panyam, M. L. Dali, G. L. Amidon, R. J. Levy and V. Labhasetwar Degradation Characteristics of PLGA Nano- and Microparticles: Effect of Particle Size AAPS PharmSci 2000 AAPS Annual Meeting Supplement. 2000; 2 (4) Available from: https://www.aapspharmaceutica.com/scientificjournals/pharmsci/am_abstracts/2000/1936.html.

This follows the American Medical Association standard format for online journals.