RT Journal Article SR Electronic T1 The Stability of Cyclophosphamide in Lyophilized Cakes. Part I. Mannitol, Lactose, and Sodium Bicarbonate as Excipients JF PDA Journal of Pharmaceutical Science and Technology JO PDA J Pharm Sci Technol FD Parenteral Drug Association (PDA) SP 29 OP 37 VO 42 IS 1 A1 Thomas R. Kovalcik A1 J. Keith Guillory YR 1988 UL http://journal.pda.org/content/42/1/29.abstract AB Lyophilized products containing cyclophosphamide and one of the following excipients: mannitol, lactose, sodium bicarbonate, or sorbitol, were prepared. All of the products were well-formed cakes with the exception of the one containing cyclophosphamide and sorbitol, which was a collapsed mass. Cyclophosphamide in lyophilized cakes containing mannitol, lactose, or sodium bicarbonate was found to undergo rapid(t90 ≈15 days) degradation in the solid state. A simple method was developed which permits introduction of measured quantities of water vapor into the lyophilized cake. In the cakes containing mannitol or sodium bicarbonate as adjuvants, differential scanning calorimetry and X-ray diffraction showed that cyclophosphamide was converted from the amorphous to the monohydrate form when exposed to moisture, and exhibited improved stability. In the case of the cake containing lactose, the lactose, but not the cyclophosphamide, was converted to a monohydrate, and the stability of the cyclophosphamide was not improved.