Uniformity of Dosage Units (UOD)

  1. USP General Chapter <905> UNIFORMITY OF DOSAGE UNITS.
  2. This USP general chapter <905> is aligned with the corresponding texts of the European Pharmacopoeia (EP) and the Japanese Pharmacopoeia (JP).
  3. To ensure the consistency of dosage units, each unit in a batch should have a drug substance (API) content within a narrow range around the label claim.
  4. Dosage units are distinct as dosage forms contain a single dose or a part of a dose of drug substance (API) in each unit.
  5. UOD specification is not proposed to apply to suspensions, emulsions, or gels in unit-dose containers intended for external, cutaneous administration.
  6. The term “uniformity of dosage unit (UOD)” is defined as the degree of uniformity in the amount of the drug substance (API) among dosage units.
  7. Unless otherwise indicated elsewhere in this Pharmacopeia, the provisions of this chapter apply to each drug substance contained in dosage units including one or more drug substances.
  8. The uniformity of dosage units can be verified by two methods,
    1. Content Uniformity (CU) or
    2. Weight Variation (WV).
  • The test for Content Uniformity (CU) of preparations presented in dosage units is based on the assay of the individual content of drug substance(s) (API) in a number of dosage units to determine whether the individual content is within the acceptable limits set.
  • The test for Weight Variation (WV) is applicable for the following dosage forms
W1Solutions are enclosed in unit-dose containers and in soft capsules
W2Solids (As well as sterile solids, powders, & granules) which, are packaged in single-unit containers and contain no active or inactive added substances
W3Solids (including sterile solids) packaged in single-unit containers, with or without active or inactive additional substances, made from real solutions and freeze-dried in the final containers, and labeled to identify the method of production;
W4Hard capsules, uncoated tablets, or film-coated tablets, containing 25 mg or more of a drug substance comprising 25% or more, by weight, of the dosage unit or, for hard capsules, the contents, excluding that uniformity of other drug substances (API) present in lesser proportions, is confirmed by meeting the requirements for Content Uniformity (CU).
  • Application of Content Uniformity (CU) and Weight Variation (WV) Tests for Dosage Forms
Content Uniformity (CU) and Weight Variation (WV) Tests for Dosage Forms
Content Uniformity (CU) and Weight Variation (WV) Tests for Dosage Forms

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