Intersection of http://www.nlm.nih.gov/research/umls/rxnorm and http://www.nlm.nih.gov/research/umls/rxnorm
This is the CodeSystem that contains codes in both RxNorm (http://www.nlm.nih.gov/research/umls/rxnorm) and RxNorm (http://www.nlm.nih.gov/research/umls/rxnorm).