In this study, planar
induced fluorescence (PLIF) was used for the first time to evaluate
variability in drug
dissolution data us
ing Rhodam
ine-6G doped tablets with
in small volume USP 2 apparatus. The results were compared with tablets conta
ined theophyll
ine (THE) drug for conventional
dissolution analysis. The impact of hydrodynamics, sampl
ing po
int,
dissolution media viscosity and pH were
investigated to note effects on release of these two actives from the hydrophilic matrix tablets. As expected mix
ing performance was poor with complex and reduced velocities at the bottom of the vessel close to the tablet surface; this mix
ing became even worse as the viscosity of the fluid
increased. The sampl
ing po
int for
dissolution can affect the results due to
in-homogenous mix
ing with
in the vessel; this effect is exacerbated with higher viscosity
dissolution fluids. The
dissolution profiles of RH-6G measured via PLIF and THE measured us
ing UV analysis were not statistically different demonstrat
ing that RH-6G is an appropriate probe to mimic the release profile of a highly soluble drug. A l
inear correlation was accomplished between the release data of the drug and the dye (
R2 > 0.9).
The dissolution profile of the dye, obtained with the analysis of the PLIF images, can be used in order to evaluate how the viscosity and the mixing performance of USP 2 mini vessel affect the interpretation of the dissolution data of the targeted drug.