RT Journal Article
SR Electronic
T1 Low Temperature Properties of Lyophilized Solutions and Their Influence on Lyophilization Cycle Design: Pentamidine Isethionate
JF PDA Journal of Pharmaceutical Science and Technology
JO PDA J Pharm Sci Technol
FD Parenteral Drug Association (PDA)
SP 135
OP 139
VO 48
IS 3
A1 Williams, N. Adeyinka
A1 Schwinke, David L.
YR 1994
UL http://journal.pda.org/content/48/3/135.abstract
AB Pentamidine isethionate is a lyophilized antiprotozoal drug. Its solutions, when lyophilized, have been found to exhibit a range of properties that depend on its concentration and the manner in which it is allowed to freeze. These properties were examined by Differential Scanning Calorimetry (DSC), freeze-drying microscopy and X-ray powder diffraction. In DSC studies, the drug exhibited eutectic behavior with a eutectic temperature of –2.8°C. Freeze-drying microscopic examination of a sample of solution after cooling at about 1°C/min showed that the sample dried with retention up to –4°C, where melting was observed. By using the appropriate drug concentration and manipulating the freezing stage, crystallization of the drug from solution could be induced during cooling to yield a crystalline end-product.