Stability testing solid state

Oxidized MWCNTs have also been tested in conjunction with solid-state electrolytes [107]. Compared to pristine MWCNTs, the oxidized MWCNTs have a better miscibility with the ionic liquids used in the electrolyte. Overall, a much improved gelforming ability resulted. The latter was clearly reflected in the device performance. In particular, devices with oxidized MWCNTs outperformed those with pristine MWCNTs and the reference devices in terms of photocurrents, Vocs, and efficiencies. Importantly, the device stability was also greatly enhanced when oxidized MWCNTs were implemented - 100 days with a loss of overall efficiency by less than 10 °/o. The authors ascribed the drop in efficiency to phase separation and subsequent leakage of ionic liquids. 

The molecular encapsulation of flavors with cyclo-dextrins was found to improve the resistence of light sensitive flavor constituents against daylight and ultraviolet irradiation. The photodecomposition of adsorbed and complexed flavors was tested both in the solid state and in aqueous solutions. The results of the light stability tests are demonstrated in the example of complexed and adsorbed citral,beta-ionone and cinnamaldehyde formulations /Table III./. 

The stability of the solid-state Ca(II)-ISE was evaluated by immersing the electrode continuously in pulp filtrate for 9 days. The electrode was removed from the pulp filtrate only to make a three-point calibration once per day. The slope was found to be stable (27 +1 mV/decade) for the whole duration of the test (9 days), and the drift of the standard potential was ca. 1 mV/day. 

In conclusion, on the basis of evaluation of the literature and kinetic considerations in conjunction with our stress-testing experience over the last 15 years, temperatures of up to 70°C (at high and low humidities) should provide a rapid, reasonably predictive assessment of the solid-state degradation pathways and relative stabilities of most drug substances at... 

Chafetz L. Practical testing of solid-state stability of pharmaceuticals. J Pharm Sci 1992 81 107. 

Pikal MJ, Dellerman KN. Stability testing of pharmaceuticals by high sensitivity isothermal calorimetry at 25°C cephalosporins in the solid and aqueous solution states. Int J Pharm 1989 50 233-252. 

More recently, Markovich et al. (91) utilized a combination of solid-state infra-red (IR) and NMR methods to study the amorphous to crystalline API transition of SCH 48461 in solid dispersion capsule formulations. In this illustrative study, dissolution testing initially revealed inter-and intralot variations of capsules stored under accelerated stability conditions (25°C/60% RH, 30°C/60% RH, and 40°C/80% RH). PXRD analysis could not explain the dissolution data being collected on lots stored at accelerated conditions and revealed no differences from original diffraction patterns. Two additional analytical techniques, attenuated total reflectance IR (ATR-IR) spectroscopy and solid-state 13C NMR spectroscopy, were employed to study the physical form in the actual solid dispersion formulations. 

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