The in-situ particle size of delavirdine mesylate in dry mix and tablets was determined.Methods
Optical microscopy and fluorescence microscopy combined with image analysis were used for qualitative and quantitative measurements.Result
Using optical microscopy, it was demonstrated qualitatively that fragmentation of the large drug particles was occurring during tablet compression. Quantitative comparisons between dry mix and tablet samples showed that in the dry mix, drug particles remain intact, with particle lengths exceeding 200 μm. In the tablets, no particles longer than 100 μm had been observed. Analysis of multiple tablet lots revealed consistent in-situ drug particle size distributions, regardless of the original bulk drug particle size.Conclusions
Bulk drug particle size of delavirdine mesylate is not predictive of the particle size in the tablet due to fragmentation of particles during compression. Optical and fluorescence microscopy are valuable tools for probing in-situ particle size in complex matrices.