6 Managing Thermal History to Stabilize/Destabilize …
101
Fig. 6.5 a Change in the crystallinity of ritonavir glass as a function of time. The storage temperature
is indicated in the Figure. The data were fitted to Avrami-Erofeev equation. b The Arrhenius plot
of induction time of crystallization of ritonavir glass. The data acquired at 45, 50, and 60 °C
were plotted. Figures are adopted with modification form Ref. [17] with permission of American
Chemical Society
Fig. 6.6 a Change in crystallinity of ritonavir glass as a function of time at 60 °C. The “No anneal”
data coincides with the “60 °C” data in Fig. 6.5a. Also presented are the crystallization data for
ritonavir glass, which was preannealed at 40 °C before the storage at 60 °C as indicated. The data
were fitted to Avrami-Erofeev equation. b Effect of preannealing time at 40 °C on subsequent
isothermal crystallization study at 60 °C for 6 days. The crystallinity after storage at 60 °C is
presented. Notably, no crystallization occurred during preannealing at 40 °C. Figures are adopted
with modification form Ref. [17] with permission of American Chemical Society
40 °C on the subsequent crystallization study at 60 °C. Crystallinity of intact ritonavir
glass reached 58% during annealing at 60 °C for 6 days. However, crystallization
was obviously retarded by preannealing at 40 °C. When preannealing was performed
for 2 days, the crystallinity after storage at 60 °C for 6 days was only 8% (Fig. 6.6b).
101
Fig. 6.5 a Change in the crystallinity of ritonavir glass as a function of time. The storage temperature
is indicated in the Figure. The data were fitted to Avrami-Erofeev equation. b The Arrhenius plot
of induction time of crystallization of ritonavir glass. The data acquired at 45, 50, and 60 °C
were plotted. Figures are adopted with modification form Ref. [17] with permission of American
Chemical Society
Fig. 6.6 a Change in crystallinity of ritonavir glass as a function of time at 60 °C. The “No anneal”
data coincides with the “60 °C” data in Fig. 6.5a. Also presented are the crystallization data for
ritonavir glass, which was preannealed at 40 °C before the storage at 60 °C as indicated. The data
were fitted to Avrami-Erofeev equation. b Effect of preannealing time at 40 °C on subsequent
isothermal crystallization study at 60 °C for 6 days. The crystallinity after storage at 60 °C is
presented. Notably, no crystallization occurred during preannealing at 40 °C. Figures are adopted
with modification form Ref. [17] with permission of American Chemical Society
40 °C on the subsequent crystallization study at 60 °C. Crystallinity of intact ritonavir
glass reached 58% during annealing at 60 °C for 6 days. However, crystallization
was obviously retarded by preannealing at 40 °C. When preannealing was performed
for 2 days, the crystallinity after storage at 60 °C for 6 days was only 8% (Fig. 6.6b).