凍結乾燥品に及ぼす, セファロチンナトリウム過飽和溶液への物理的刺激の影響(第1報)

Abstract

A method of seeding and subsequent freeze-drying of aqueous cephalothin sodium (CET-Na) of supersaturated concentrations was employed in an experiment with a regular production scale. The freeze-dried plugs of non-uniformity in appearance were consequently obtained together with those of white in color and in high uniformity in appearance. Such plugs of irregular shape have been found to show a marked color development during storage, and the reconstitution time was also prolonged. Scanning electron microscopy, powder X-ray diffractometry, and thermogravimetry have all demonstrated that the plugs of irregular appearance show dense aggregates of fine crystals of a high non-crystallinity by an incomplete crystal growth. Investigation has then been made with supersaturated CET-Na solution, which has preliminarily received varying mechanical stresses in varying time courses of temperature, similarly to a regular production program, for the purpouse of achieving the reproducibility of such unacceptable plugs. It has been demonstrated that by a more prolonged storage at a lower temperature of CET-Na in supersaturated solution the plug may surely contain aggregates of more fine crystallites of a higher non-crystallinity, accordingly have a higher irregularity in appearance and exhibit a more marked deterioration in pharmaceutical qualities.