Having determined the source of the new diffraction data we can begin to understand the process of the conversion between glycolide and HAA. We postulate that the hygroscopic nature of MCC increases the moisture content inside the blend to drive and increase the rate of hydrolysis. Suzuki and Nakagami showed that MCC with a higher amorphous content was more hygroscopic than with a higher crystalline content (25% vs. 65% crystallinity) with an ~8% increase in moisture uptake for the higher amorphous content MCC. In general, cellulose has a crystallinity that varies between 53-82% depending on the source of the MCC. In addition, glycolide is hygroscopic itself which will enhance the uptake of moisture hence conversion was observed in the pure phase as well, albeit more slowly. The stored tablets appeared to have a rougher surface compared to their initial state which can be accounted for by the recrystallization of HAA as the hydrolysis reaction occurred. The low temperature storage conditions and slower rate of crystal growth will have contributed to the production of a highly crystalline powder. Over this time the presence of MCC within the tablets does not change hence the degradation of the glycolide does not appear to have affected the MCC. Our observation is supported by previous investigations into various grades of MCC using X-ray diffraction, which did not show any significant change to the diffraction pattern despite being subject to various environments