Microbial growth in small-volume pharmaceuticals.

The ability of aseptically filled pharmaceuticals to support microbial growth was tested on 43 small-volume products (mainly parenterals). These were inoculated with a variety of microorganisms which were known to be associated with contamination of pharmaceutical products. In general, Gram-negative bacteria were found to be much more likely to grow than Gram-positive. It was possible for an inoculum of a few cells to multiply to levels up to 10(7)/mL. The presence of preservatives also influenced the likelihood of growth, 12 out of 19 (63%) of the pharmaceuticals without preservatives supporting growth of one or more microorganisms; only 3 out of 24 (12%) of those with preservatives supported growth. The importance of these observations is discussed with reference to formulation of aseptically filled products, environmental sampling and the quality of cleanroom conditions necessary for production. It is suggested that those pharmaceuticals which are designed to be sterile but not to be terminally sterilized, should be tested before production begins, for their ability to support microbial growth. In this way, the risks involved in aseptically filling can be ascertained. A test is proposed in which "indicator" microorganisms would predict the likelihood of pharmaceutical formulations supporting growth.

Prevention of graft-versus-host disease by ex vivo T cell depletion: reduction in graft failure with augmented total body irradiation.

Graft-versus-host disease prevention was attempted in 35 consecutive patients with hematological malignancy who received bone marrow from an HLA match sibling donor who was depleted of T cells ex vivo. Five of the first 8 patients who received cyclophosphamide 60 mg/kg on 2 consecutive days followed by fractionated total body irradiation (TBI) (6 x 2 Gy) had graft failure. The subsequent 27 patients had received an extra fraction of TBI (7 x 2 Gy), and only one failed to have stable engraftment. There were no differences in nucleated cell dose, granulocyte-macrophage colony-forming units, or T cell numbers given to the two groups. Neutrophil but not platelet regeneration of those patients who successfully grafted was slower than in a group of historical controls receiving unmanipulated marrow. Significant graft-versus-host disease was prevented with no increase in relapse rate. We suggest that engraftment can be reliably achieved by augmenting the TBI conditioning in recipients of T cell-depleted matched allogeneic bone marrow.