The current version
USP XX generated controversy in the industry, and given the emphasis placed on control of the sterilization process, additional
detail was proposed in 1982 (17) for addition to the introductory section of the chapter, which was proposed to undergo a
name change to "Sterilization and Sterility Assurance of Compendial Articles." This section described sterilization process
validation as having an installation qualification, an operational qualification, a confirmatory stage, and a final stage
(for completion of documentation). Selection and control of biological indicators for sterilization validation are described,
as is a general review of process control subjects. Each method of sterilization included in the chapter is expanded to include
at least a short discussion of validation concerns. There is a great deal of material added to the ionizing radiation and
the filtration sections in this regard.
The 1982 Pharmacopeial Forum in-process revision draft also expanded the sterility testing section. Among the additions was a definition of product "lot"
for sterility-test purposes and the assertion that a 1–2% false-positive rate was acceptable for the sterility test. This
addition was viewed as justification for a second-stage test if the first-stage test failed.
A further revision (with extensive editorial rewrites) appeared in the May–June 1983 Pharmacopeial Forum (18) followed immediately
by a second rewrite in the Sept.-Oct. Pharmacopeial Forum (19). The second draft of 1983 contained modest editorial changes, with the exception of the removal of a description of
minimum standards for an aseptic manufacturing facility and some of the more onerous requirements for sterility testing (e.g.,
requiring the test facility be fully validated and the use of negative controls on the test). It was this version that appeared
in USP XXI (20).
Refinements to the basic chapter were proposed in 1986 (21) to clarify some points regarding filtration and aseptic processing
and to keep pace with changes in the contemporary sterility test chapter, primarily clarification of the bacteriostasis/fungistasis
test (22). This version appeared in USP XXII (23).
Concerns were raised in the field about the handling of sterilization by filtration in the revised chapter and a proposed
revision to address these concerns appeared in 1990 (24). These changes were accepted and appeared in USP 23 (25). The chapter has not changed appreciably since.
Revisions currently under consideration
The sterilization chapter is significantly, and obviously, in need of revision (26, 27). This task was attempted with a proposed
short-term revision published in 2004 for review (28). The major changes proposed in the 2004 revision were:
- Elimination of references to the old sterility test ‹71› and to first- and second-stage testing
- Updating the names of microorganisms to current taxonomy
- References to units of measure (Mrad) currently in use
- Elimination of references to discontinued standards (especially Fed Standard 209)
- Reference to new consensus standards (ISO 13408-1)
- Discussion of contemporary aseptic processes.