RT Journal Article SR Electronic T1 Microfractures in Parenteral Glass Ampuls JF PDA Journal of Pharmaceutical Science and Technology JO PDA J Pharm Sci Technol FD Parenteral Drug Association (PDA) SP 18 OP 20 VO 35 IS 1 A1 Crouthamel, T. G. YR 1981 UL http://journal.pda.org/content/35/1/18.abstract AB The phenomenon of microfractures occurring in minute areas of devitrified glass in flame-sealed ampuls is explored and identified as a possible cause of content degradation or ampul tip leaking that is found after final product release. The only definitive research on this subject by one firm indicates that it is impossible to predict which areas of devitrification will fracture, or when such a phenomenon will occur. Their unpublished data show that the microfractures vary in width between 0.15 to 0.5 μm, with some spreading to 2.5 μm, and pass completely through the tip. Their data show that the fracturing occurs on an average of 2% of each lot produced. Research of the literature disclosed few published papers of any kind on the general subject of leakers in sealed ampuls which had passed the dye test. Visits to glass manufacturers also revealed that they knew of only a very few such cases. Because of the physical size of the cracks and the physical properties of parenteral solutions, visible evidence of such microfractures in the form of leakers would be very rare. The usual dye test cannot detect such small cracks in ampuls. Because there is little knowledge about how often rupturing of devitrified glass takes place, extrapolation of one firm’s experience with microfractures to the rest of the small volume parenteral industry may reveal more such microfractures than the industry or the FDA have previously suspected.