Stability testing degradation products

We know that the product degraded more than 10% (450 mg/mL) over the 12-week period. In addition, in the tenth week of accelerated stability testing, the product degraded at an increasing rate. The chemists want to know the rate of degradation, but this model is not linear. Table 4.2 shows the multiple regression analysis of y on Xi and X2 for Example 4.1 (Table 4.1)... 

In general, stabilizers function by reaction with proplnt decompn products. A number of methods have been described and a preliminary evaluation of these methods was conducted by several labs under a cooperative program. Based on results from these screening tests, the PicArsn spec tropho tome trie methods for available stabilizer and primary degradation products were selected for further study. The initial phase of this program was an attempt to standardize the necessary spectrophotometric factors. Significant differences with regard to the factors obtained... 

Peptide synthesis from y9-amino acids is particularly attractive for first feasibility micro-reactor tests as there are no chiral centers which may complicate analysis of the products [5, 88]. y0-Peptides are also attractive owing to their stmctural and biological properties, especially concerning the stability versus degradation by peptidases as compared with their a-analogues (see original citations in [5]). 

Biodegradable poly(phosphoester-urethanes) containing bisglycophosphite as the chain extender were synthesized. Methylene bis-4-phenyl isocyanate (MDI) and toluene diisocyanate (TDI) were initially used as diisocyanates. Since there was a concern that the degradation products could be toxic, the ethyl 2,6-diisocyanatohexanoate (LDI) was synthesized and replaced the MDI (or TDI). The hydrolytic stability and solubility of these polymers were tested. Preliminary release studies of 5-fluorouracil from MDI based poly(phosphoester-urethane) and methotrexate from LDI based poly(phosphoester-urethane) are also reported. 

Before testing, the solutions should be neutralized if necessary. If the method is suitable for stability studies, then the peak due to the major components will be reduced and other peaks will probably be represented. These degradation products should be resolved from the parent peak. 

Failed USP dissolution test requirements Microbial contamination of non-sterile products Lack of efficacy Impurities/degradation products Lack of assurance of sterility Lack of product stability Labeling Label error on declared strength Misbranded Promotional literature with unapproved therapeutic claims... 

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