Contains selections from the writings of physicians, the originals of some of whose works no longer exist, and who would have been forgotten, but for the compilations of Oribasius. Writers included are Agathinus, Antyllus, Apollonius, Archigenes, Athenaeus, Ctesias, Dieuches, Diocles, Dioscorides, Herodotus, Justus, Lycus, Menemachus, Mnesitheus Atheniensis, Mnesitheus Cyzicenus, Oribasius, Philagrius, Philotimus, Philumenus, Sabinus, Xenocrates, Zopyrus. 

"Born in Pergamum, he [Oribasius] studied medicine at Alexandria under Zeno of Cyprus, and practised in Asia Minor. He became the personal physician of Julian, who took him to Gaul (355). Closely involved in the proclamation of Julian as emperor (361), Oribasius accompanied him until his death in Mesopotamia (363). Banished for a time to foreign courts, Oribasius was soon recalled by the emperor Valens and continued to practise his profession until an advanced age. His principal works are a collection of excerpts from Galen—now lost—and the Collectiones medicae, a vast compilation of excerpts from earlier medical writers, from Alcmaeon of Croton (c.500 bc) to Oribasius' contemporaries Philagrius and Adamantius. Both of these works were written at the behest of Julian. Of the 70 (or 72) books of the Collectiones only 25 survive entire; but the rest can be in part reconstructed from the Synopsis ad Eustathium, and the treatise Ad Eunapium, epitomes of the Collectiones in 9 books and 4 books respectively made by Oribasius himself, and from various excerpts and summaries, some of which are still unpublished. Oribasius was a convinced pagan, and his medical encyclopedia is a product of the vain effort of Julian and his circle to recall the classical past. For the medical historian its importance lies in the large number of excerpts from lost writers—particularly those of the Roman period—which it preserves, usually with a precise reference to the source; Oribasius adds nothing of his own. His work was constantly quoted and excerpted by early Byzantine medical writers, the Synopsis and the Ad Eunapium were twice translated into Latin in Ostrogothic Italy, and Syriac and Arabic translations of portions of Oribasius' work form one of the principal channels by which knowledge of Greek medicine reached the Islamic world" (Robert Browning & Vivian Nutton, Oxford Reference; http://www.oxfordreference.com/view/10.1093/oi/authority.20110803100254300)

Digital facsimiles from Corpus Medicorum Graecorum at this link