Taylor:Research: Difference between revisions
Line 15: | Line 15: | ||
For extremely poorly water soluble compounds, an important question that has to be addressed is "how much can the solubility be increased by using a solubility enhancing formulation?". This is a difficult question to address. For solubilization strategies that lead to supersaturation, it is crucial to consider the phase behavior of the compound. Relevant phase transitions are crystallization of the drug and liquid liquid phase separation. If crystallization is rapid, then it may be very difficult to achieve sustained solubility enhancement. In this instance, it is important to determine if crystallization inhibitors can be added to the formulation to help prolong the supersaturation duration. For compounds that crystallize more slowly from water, if the solution is highly supersaturated, the spinodal decomposition point may be exceeded resulting in liquid-liquid phase separation (LLPS). The resulting disperse phase may appear solid-like or liquid-like depending on the glass transition temperature of the phase separated material. In this instance, the solution will remain supersaturated, despite containing a precipitate, and the supersaturation will persist until crystallization occurs. It is therefore important to understand the different types of precipitation phenomena that can occur from supersaturated solutions. | For extremely poorly water soluble compounds, an important question that has to be addressed is "how much can the solubility be increased by using a solubility enhancing formulation?". This is a difficult question to address. For solubilization strategies that lead to supersaturation, it is crucial to consider the phase behavior of the compound. Relevant phase transitions are crystallization of the drug and liquid liquid phase separation. If crystallization is rapid, then it may be very difficult to achieve sustained solubility enhancement. In this instance, it is important to determine if crystallization inhibitors can be added to the formulation to help prolong the supersaturation duration. For compounds that crystallize more slowly from water, if the solution is highly supersaturated, the spinodal decomposition point may be exceeded resulting in liquid-liquid phase separation (LLPS). The resulting disperse phase may appear solid-like or liquid-like depending on the glass transition temperature of the phase separated material. In this instance, the solution will remain supersaturated, despite containing a precipitate, and the supersaturation will persist until crystallization occurs. It is therefore important to understand the different types of precipitation phenomena that can occur from supersaturated solutions. | ||
== | == Solid State Stability == | ||
[[image:Deliquescence.png|thumb|200px|right]] | [[image:Deliquescence.png|thumb|200px|right]] | ||
Maintaining the solid state stability of drug in a dosage form is extremely important to ensure product quality. Changes that can occur in dosage forms include conversion of a salt to the free form, polymorphic transformations, crystallization of amorphous solids, and deliquescence of highly soluble components. These changes can lead to variations in product performance such as reduced dissolution rates or increased tablet hardness. We are interested in detecting, characterizing and understanding factors that impact solid state phase transformations. | |||
Revision as of 12:05, 3 January 2014
|