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2	Compound Stability Factors that may affect stability in DMSO Storage time Temperature Concentration Freeze/Thawing Water Uptake
3	A number of Stability Studies have been performed to define best practice for storage of liquid samples at GlaxoSmithKline 1995 530 Compounds in sealed NMR tubes (RT,4ºC) 1998 297 CORE 96 compounds lidded (4ºC,-20ºC) 2000 342 CORE 98 compounds sealed at -20ºC 2001/2002 Freeze/Thaw Study at 4ºC 2001/2002 Sealed/Lidded Study at 4ºC QA project
4	ALS Stability Studies 1995: 530 compounds sealed in NMR tubes* RT: 4% (1 month) 8% (4.5 month) 4ºC: 2% (1 month) 4% (6 month) * Percentage of compounds degraded by >50% Less degradation at 4ºC vs. RT
5	ALS Stability Studies 1998: 297 CORE 96 compounds (lidded)* 4ºC (17%RH): 6% (1mon) 9% (3mon) 23% (6mon) -20ºC 5% (3mon) 12% (6mon) * Percentage of compounds degraded by >50% Degradation: -20ºC <4ºC <RT Degradation: Sealed<Lidded
6	ALS Stability Studies 2000: 342 CORE 98 compounds (sealed)* Sample degradation and water uptake monitored -20ºC 0.3% (3mon) 0.3% (6mon) 1.8% (1yr) 3.5% (2yr) * Percentage of compounds degraded by >50% This is a 5 year study - 3 year timepoint Jan 2003
7	Water Uptake Results Samples stored in master blocks at -20ºC, 10mM solution Blocks sealed with Beckman foil seal Karl Fischer titration was used to monitor the % water uptake by DMSO Clear correlation between position on plate and water uptake Water uptake increases with time
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9	Effect of Freeze Thawing and Storage Time on Degradation Investigated by combining stability and freeze thaw in a factorial design experiment 17 combinations of freeze thaw + storage time 160 compounds randomly selected 2mM conc. stored in 384 deep well blocks at 4ºC and 5% relative humidity Samples analysed for degradation using LC-MS and KF for % water uptake.
10	RESULTS
11	RESULTS 20 most degraded compounds were investigated separately The effect of storage time was highly significant There was no effect of freeze-thaw on degradation
12	Sealed/Lidded Study This study was used to demonstrate: The difference in water uptake between samples in DMSO that are stored sealed and samples that are stored with a loose fitting lid The effect of water uptake on sample stability 160 randomly selected compounds 80 unstable compounds selected Samples were stored for 6 months at 4ºC, no humidity control Stability monitored using LC-MS
13	Sealed/Lidded Results Water Uptake Lidded plates take up more water than sealed plates Corners>Edges>>Internal Stability Sealed plates are more stable than lidded plates After 3 months: Purity <80% Sealed 11% Lidded 37%
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15	Comparison of Sealed vs. Lidded
16	CONCLUSION These studies have shown that many factors can influence compound degradation. These include: storage time storage temperature humidity conditions (water uptake)
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33	Phase 2 Samples that failed Phase 1 will be ordered as solids by plate look up code. The samples will be analysed by LC-UV-ELSD-MS and/or NMR. Samples that pass will enter accelerated degradation studies.
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