Short-term stability analysis

For the first set of materials, and with the aim of assessing the dispatch conditions, a short-term stability study was conducted at 40°C. The layout chosen for the stability study was the so-called isochronous scheme samples were taken from the bulk, placed at 40° C and then moved back to the reference temperature (4°C), after 1 and 2 weeks. Then, at the same time, the samples were analysed for major components and trace elements. The results, 3 time-points (0, 1, 2 weeks) and 2 units analysed per time-point, were evaluated by one-way analysis of variance ANOVA. As some parameters (especially As, Cd, Cu, and to a minor extent also Mn, pH) showed a statistically significant slope of the regression line, it was decided to assure the dispatch of the samples at 4°C (with cooling elements). 

Filters were kept at respectively +5°C and +20°C over a period of 12 months, and the Cr(VI) and total soluble Cr contents were determined at regular intervals during the storage period. An additional stability test was performed after 29 months, consisting in the determination of Cr(VI) at +20°C followed by a short term stability test at +40 C to simulate worst-case transport conditions. Tests were made after 1 week, 1, 6 and 12 months. Samples were analysed using the same procedure as for the homogeneity study. Cr(VI) and total soluble Cr were each determined in three fold (one replicate analysis in each of 3 filters stored at different temperatures) at each occasion of analysis. No instability could be found at any of the temperatures tested even storage at +40°C for 14 days does not likely affect the samples. 

Other sulphur(II) compounds also form self-assembled layers on gold and silver surfaces. Alkyl xanthate ions ROCS2 are coordinated to the surface through both S atoms and therefore have good stability. FT-IR analysis revealed that alkane chains in these monolayers are well-packed and ordered. Alkyl xanthates and dithiocarbamates were also reported to form monolayers on the surface of Ag coUoids . Thioalkanoic acids RCOSH form well-packed monolayers on both Au(lll) and Ag(lll) surfaces. However, these monolayers exhibit only short-term stability due to hydrolysis of the thiocarboxyl group. ... 

Stability testing is performed to ensure that the analyte concentration does not change during sample storage, sample preparation, and sample analysis. The freeze and thaw stability of analyte in matrix as well as the short-term stability of analyte in matrix at room temperature should be examined. The long-term stability of analyte in matrix stored in freezer should also be tested, as should the stability of stock solution and working solutions ofthe analyte and internal standard. The stability of the analyte (and IS) is satisfactory when the determined concentration is within the limits of accuracy. 

In patients with acute PE, the use of thrombolytics provides short-term benefits such as restoring pulmonary artery patency and hemodynamic stability.8,26 A recent meta-analysis of nine small randomized clinical trials showed a slightly lower risk... 

Gika et al. [98,99] investigated short-term sample stability for human urine by LC-MS. Urine samples were collected from normal female and male volunteers into containers containing one protease tablet and frozen at -80°C or -20°C for one month. Upon defrosting, samples were centrifuged at 13,000rpm for lOmin and then diluted 1 4 with 0.1% formic acid for LC-MS analysis. All samples were kept at 4°C in an autosampler. LC-MS analyses showed that there were no differences observed between samples stored at -80°C or -20°C even after 1 month. Therefore, storing urine samples at -20°C for at least one month is acceptable. In addition, based on principal component analysis (PCA) the data obtained from samples that had been subjected from one to nine freeze-thaw cycles showed that overall stability of the samples was also acceptable. 

Stability Complete sample analysis ASAP due to lack of stability data Determine short and long-term stability for critical reagents and QCs in matrix Determine short and long-term stability for critical reagents and QCs in human matrix... 

In this article we discuss the problem of understanding the long-term stability properties of a solution of a quasi-integrable Hamiltonian system by means of a Fourier analysis on a short observation time. Precisely, even for resonant chaotic motions, we will show how the combined use of Fourier analysis and Nekhoroshev theorem allows to understand the stability properties on a time T exp(T), where T is a suitable observation time, of the order of the resonant period. To be definite, we will refer to quasi-integrable Hamiltonian systems with Hamiltonian of the form ... 

In general, proper statistical analysis of long-term stability data collected, as recommended in Section VII.E, should support at least a 1-year expiration dating period. Exceptions do exist, for example, with short half-life radioactive drug products. 

---