For intrinsic dissolution testing, a drug pellet (i.e., the dissolution test sample) is retained within a cylindrical recess in a sample holder that is placed at the bottom of a dissolution vessel containing an appropriate dissolution medium with the sample holder oriented with the drug pellet facing up. During the testing cycle, the dissolution medium may be stirred, e.g., using a conventional USP 2 rotating paddle, while the sample holder (and drug pellet) remain stationary at the bottom of the vessel. The orientation of the drug pellet during testing (i.e., facing up) decreases the likelihood of retention of air bubbles formed at the surface of the drug pellet (which bubbles could otherwise decrease the effective dissolution rate), thereby providing more accurate and consistent intrinsic dissolution test results.

The invention relates to a formed tablet calibration standard-reagent for calibrating Karl Fischer reactions for determining water content in a substance, the reagent containing a first component, namely sodium tartrate dihydrate, and a second component, namely magnesium stearate. The invention further relates to a method for determining the water content of a substance using a Karl Fischer analysis. The invention further relates to a formed tablet calibration standard-reagent kit that includes a sealed package containing a formed tablet calibration standard-reagent for a Karl Fischer reaction.

The present invention relates to a formed tablet calibration standard-reagent for Karl Fischer reactions to determine the water content of substances, such as pharmaceuticals, food stuffs, and oils.