text: Unlike the London Pharmacopoeia, the Edinburgh Pharmacopoeia went through many editions and revisions. In the 142 years from initial publication to the merging into the British Pharmacopoeia, the Edinburgh Pharmacopoeia had twelve acknowledged editions, the last two in English. Opposition to revision argued that it made the pharmacopoeia appear unstable but proponents argued it kept the pharmacopoeia relevant with scientific and medical developments. The last two editions were published in English under the title The Pharmacopoeia of the Royal College of Physicians of Edinburgh. From 1864, the Edinburgh Pharmacopoeia combined with the London and Dublin editions to create the British Pharmacopoeia, which is still in circulation today.