title: The gravimetric method for the determination of residual moisture in freeze-dried biological products.
abstract: The gravimetric test for the determination of residual moisture in freeze-dried biological products performed in a humidity- and temperature-controlled room with the use of scrupulous gravimetric analytical technique can be used to accurately determine residual moisture in freeze-dried biological products such as antihemophilic factor (human) or honey bee venom allergenic extract. This method determines the first water of hydration of sodium tartrate dihydrate (7.93%) to within 1.3% of the calculated value with a relative standard deviation of 0.3% for 10 replicates. For this gravimetric procedure, freeze-dried samples containing from 1.12 to 4.4% residual moisture had relative standard deviations ranging from 3.6 to 9.1%. Samples containing less than 1.0% residual moisture by the gravimetric method such as intravenous immune globulin and antihemophilic factor (human) had relative standard deviations ranging from 16.7 to 47.0%. Relative standard deviations for residual moisture tests performed on comparable samples by the Karl Fischer and thermogravimetric methods showed similar variability.
authors.affiliation: Department of Health and Human Services, Food and Drug Administration, Bethesda, Maryland 20892.
authors.forename: J C
authors.initials: JC
authors.lastname: May
authors.forename: R M
authors.initials: RM
authors.lastname: Wheeler
authors.forename: E
authors.initials: E
authors.lastname: Grim
mesh_terms: D000818:Animals; D005612:Freeze Drying / Q000379:methods*; D006813:Humidity; D011309:Preservation, Biological; D014612:Vaccines
chemical_list: D014612:Vaccines