PT  - JOURNAL ARTICLE
AU  - Thomas R. Kovalcik
AU  - J. Keith Guillory
TI  - The Stability of Cyclophosphamide in Lyophilized Cakes. Part I. Mannitol, Lactose, and Sodium Bicarbonate as Excipients
DP  - 1988 Jan 01
TA  - PDA Journal of Pharmaceutical Science and Technology
PG  - 29--37
VI  - 42
IP  - 1
4099  - http://journal.pda.org/content/42/1/29.short
4100  - http://journal.pda.org/content/42/1/29.full
SO  - PDA J Pharm Sci Technol1988 Jan 01; 42
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.