%0 Journal Article %T Theory and practice of pharmacopoeial control of quality of drugs and excipients IX. The problem of tolerance limits for the content of active substances and excipients in the European Pharmacopoeia (Ph. Eur.). %A Šubert J %A Kolář J %J Ceska Slov Farm %V 68 %N 3 %D 2019 %M 31431018 暂无%X Content tolerance limits should respect the acceptable variation in the content of the active substance or excipient from its production and the variability of the results of the analytical procedure prescribed to determine the content by the appropriate pharmacopoeia. This usually prevails in the active substances and excipients. They should be derived statistically based on the precision of the prescribed analytical method determined by the interlaboratory test. Calculations from published precision characteristics show that some tolerance intervals for the active substance content are probably too narrow in Ph. Eur. This can lead to erroneous decisions about their quality.