The PQRI Excipient Working Group developed three surveys to gather responses from each of three respondent groups: excipient
manufacturers, excipient distributors, and drug-product manufacturers. The surveys gathered information about excipient-control
strategies used by companies that manufacture, distribute, and sell prescription-only and over-the-counter drug products for
US-only or US-and-world markets. The anonymous surveys could be completed electronically by individuals belonging to the PQRI
member organizations (http://
http://www.pqri.org/) and other interested persons. The survey period was from June 13, 2005 to Oct.14, 2005.
Figure 4: Respondents reporting difficulty finding manufacturer of USP–NF grade excipients.
PQRI received responses from 180 drug-product manufacturers, 26 excipient manufacturers, and 6 distributors of pharmaceutical
excipients. It should be recognized that PQRI is a unique US-based organization and that the survey questions were developed
in the United States. Some survey responses may, however, have come from companies that manufacture their products for distribution
and sale outside, as well as within, the United States.
Figure 5: Obstacles to labeling excipients as USP–NF.
This report presents findings of the three surveys and an analysis of survey responses. For the purposes of this report, the
terms "excipient user" and "drug-product manufacturer" mean the same, and are used interchangeably throughout the document.
The survey clearly indicates that the majority of excipient manufacturers, excipient distributors, and drug-product manufacturers
make their products for global distribution (see Figure 1). They test their excipients according to USP–NF monographs and general chapter methods (see Fig. 2). Almost all (97%) drug-product manufacturers perform more than just the
identification test when receiving excipients from their vendors along with Certificates of Analysis (C of A). The additional
tests include analyses for desired physical and chemical properties.
Figure 6: Respondents reporting inspections or visits by FDA (for either drug excipient or food use).
Less than 20% of drug-product manufacturers accept some or most material based on the excipient manufacturer's process controls
and on in-process tests. These controls and tests are not mentioned on C of A, but provide assurance of conformity with USP–NF requirements (see Figure 3). This area offers opportunities for excipient manufacturers and drug-product manufacturers to
research and subsequently use information and knowledge that lies in the excipient-maker's "manufacturing process-controls"
and "in-process test results" domain. Assessment of such information could also confirm (or otherwise indicate) certain physicochemical
quality aspects of an excipient batch, or qualities of an excipient produced under continuous manufacturing conditions.