PDA Comments on USP Harmonization Effort
PDA has commented on the proposed revision to USP <381>. USP has proposed to harmonize the chapter with Section 3.2.9 of the European Pharmacopeia (EP), “Rubber Closures for Containers for Aqueous Parenteral Preparations, for Powders, and for Freeze-Dried Powders.”
According to a letter from Russell E. Madsen, PDA’s senior vice president of science and technology, PDA supports the harmonization. “PDA applauds the proposal,” he writes. “Since U.S. manufacturers of rubber closures have been marketing products that comply with EP for many years, harmonization of USP with EP reduces the testing and administrative burden of dealing with essentially similar yet different requirements.”
PDA’s Packaging Science Interest Group (PSIG) reviewed the proposal and made a few recommendations regarding chapter heads, content, and format. For instance, PDA would like to see “relative density” changed to “specific gravity” and “sulphur content” changed to “sulfur content” to reflect conventional U.S. spelling.
The association suggested omitting “determination of sulphated ash” in the Characteristics section, since the ash content is contained in Identification Test C-Residue on Ignition; omitting “UV absorption…extract,” since this test is already included in the proposed USP revision; and omitting “IR absorption…pyrolysate,” since this is Identification Test B.
Under Test Procedures, Pretest Preparation of Sample, PDA recommends omitting the phrase, “If closure siliconization has been found to skew physicochemical analysis results, this process may be eliminated from the processing steps.” Madsen writes that “it would be difficult to know if the results are skewed and which test results are correct-those with silicone or those without.”
Under Test Procedures, Biological Tests, the proposed revision specifies use of the Agar Diffusion Test in USP<87>. PDA recommends using the Elution Test in USP<87>, “since historically the Elution Test has been the method of choice for closure suppliers, pharmaceutical manufacturers, and contract testing laboratories. ‘Formulation Characteristics’ data sheets distributed by rubber closure suppliers have most commonly contained toxicity data obtained by the Elution Test,” Madsen writes. Also, “the current version of USP<381> does not specify which of the three test procedures described in USP<87> (Agar Diffusion, Direct Contact, and Elution) must be used. Since Elution is the most commonly used there is no need to now specify another test.”
Among other changes, PDA suggests adding a new header, Functional Tests, under Test Procedures, so USP<381> would describe four types of tests: Identification, Biological, Physicochemical, and Functional.
Proposed changes to USP <381> will be published in the January/February issue of the Pharmacopeial Forum.