Vial breakage

N. A. Williams, Y. Lee, G. P. Polli, and T. A. Jennings, The effects of cooling rate on solid phase transitions and associated vial breakage occurring in frozen mannitol solutions, J. Parenter. Sci. Technol., 40,135-141 (1986). 

This step is so important that some laboratory plants, and usually all pilot and production plants, are equipped with respective mechanisms. The principle is simple The shelves are connected flexibly with inlet and outlet of the brine. The shelves are pressed together, one after the other, by a plate, which is moved by an external force in this way the stoppers are pushed into the closed position. If the pressure necessary for this stopper movement is 1 kg per stopper, the resulting total force for 100 vials per shelf is 100 kg, but if 10 000 vials are loaded per shelf, the total force is 10 tonnes, which has to be applied evenly in order to avoid vials breakage. 

Some problems developed in sample preparation and irradiation because of the variety of sample matrices submitted for INAA. Some samples were particulates (coal, fly ash, bottom ash, ore), some were volatile hydrocarbons (gasoline, jet fuel, etc.), some were aqueous, and some were solids. Our methods of sample preparation were refined to provide all samples in sealed quartz and polyethylene vials for irradiation (see Figure 1). Depending on the contents of the quartz vials, the length of irradiation was varied from 3-12 hrs to minimize vial breakage from... 

Williams, N.A., Gugliemo, J. Thermal mechanical analysis of frozen solutions of mannitol and some related stereoiso-meres evidence of expansion during warming and correlation with vial breakage during lyophilization. PDA J. Parenteral Sd. Technol. 47,119-123, 1993... 

Williams, N. A., and Dean, T. (1991), Vial breakage by frozen mannitol solutions Correlation with thermal characteristics and effect of stereoisomerism, additives, and vial configuration,/. Parenteral Sci. Technol.,45, 94-100. 

Impact of process on crystallization mannitol crystallization and vial breakage. Aqneons mannitol (5%) freeze-dried at a product temperature of -15°C during primary drying. (Data taken from Ref. 4.)... 

The new apparatus for automating this whole process in a 96 well format is shown disassembled in Figure 9.7A.The three metal pieces are made from anodized aluminum. The bottom plate sets the correct micro-titer plate footprint. The middle piece holds the glass vials in place. The top piece has holes appropriate for a 96-well autosampler. Tapered glass vials are used for their cleanliness, acid resistance, and volume efficienqr. A Teflon insert between the middle metal piece and the lips of the vials prevents vial breakage when the device is sealed with a Teflon/silicone membrane and screw clamps. Assembled, the apparatus has a standard %-well plate footprint, ready to be used as illustrated in Hgure 9.1 B, in commercial autosamplers. 

The risk of vial breakage may be significant during oversealing particularly when automatic equipment is used for this operation. Two types of mechanical oversealers are commonly used ... 

Both types of oversealer require careful adjustment to ensure an acceptable seal with minimum vial breakage. Alternatively, vials may be sealed with a screw cap rather than an aluminium overseal and these alternatives may be safer to use when hazardous products are processed. 

The volume of production over a period of time is defined as throughput. Throughput can be affected by problems with the container/closure system such as vial breakage, incomplete stoppering, extended drying times for closures, or poor sublimation rate due to a poor package design. 

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