Stability and Beyond-Use Date of a Compounded Thioguanine Suspension.

Thioguanine (TG) is available only in the form of 40 mg tablets in the United States, and the patient population in which TG is used comprises mostly children. Recognizing its importance as a therapeutic agent and limited stability data for its compounded preparation, the United States Pharmacopoeia has listed TG in its priority list of compounded preparations monographs. The goal of the present study was to generate stability data and establish a beyond-use date for compounded TG suspension.

Design and Performance of an Inexpensive Water Activity Meter.

Water activity refers to the amount of water in a system that is available for microbial growth. Commercial water activity meters are precision instruments with the ability to determine water activity to within 0.001 units and carry prices of $10,000 or more.