The HPUS is "written" by a group of pharmacists, physicians and lay people who meet 3-6 times a year to review monographs (information about specific drugs) and pharmacy procedures. Currently, there are about 1,350 drugs in the Pharmacopœia, 440 or so are prescription in some potency and 20 or so are Rx. For a drug to be included in the HPUS, it needs to have sufficient clinical data or proving to show efficacy. The process for review is very formal as are the criteria for acceptance. Both Resonance and Homeopathy Today have published extensively on these topics. All of the Pharmacopœia's activities are published for 90 days for public comment in Resonance and Homeopathy Today, among others. The decisions are finalized by the HPUS Board of Directors. OTC/Rx status is determined by the criteria outlined in the CPG, effectively toxicity and OTC uses for the products, i.e. a drug needs to be non-toxic and have an OTC indication for it to be classed OTC. The HPRS is a dynamic document, which can change. The changes are published in June and December of each year.