Quality control stability

HPLC is a complex analytical methodology that involves the development of a unique method for each new application. This method development often requires the optimisation of several method conditions to achieve a desired selectivity and sensitivity [12,13]. HPLC is also one of the most commonly applied analytical techniques and is in widespread use throughout the pharmaceutical industry for applications as diverse as quality control, stability studies and clinical trials. These two reasons mean that HPLC has been the focus of most research into ruggedness testing procedures because it is most likely to require extensive ruggedness... 

Vasselle, B. Gousset, G. Bounine, J.-P. Development and validation of a high-performance hquid chromatographic stability-indicating method for the analysis of Synercid in quality control, stability and compatibility studies, J.Pharm.BiomedAnal., 1999,19, 641-657. 

The growth of a well ordered fullerene monolayer, by means of molecular beam epitaxy, has been used for the controlled nucleation of single crystalline thin films. The quality and stability of molecular thin films has been shown... 

Each of the PLgel individual pore sizes is produced hy suspension polymerization, which yields a fairly diverse range of particle sizes. For optimum performance in a chromatographic column the particle size distribution of the beads should be narrow this is achieved by air classification after the cross-linked beads have been washed and dried thoroughly. Similarly, for consistent column performance, the particle size distribution is critical and is another quality control aspect where both the median particle size and the width of the distribution are specified. The efficiency of the packed column is extremely sensitive to the median particle size, as predicted by the van Deemter equation (4), whereas the width of the particle size distribution can affect column operating pressure and packed bed stability. 

A dossier that focuses on quality (manufacture, control, stability) and labelling of the product must be submitted in support of the application. 

Enzyme Reference Serums. Several companies sell lyophilized or stabilized reference serums for the calibration of instruments and for quality control. The label values given for the enzymatic activity of these serums should never be taken at face value, as at times they may be quite erroneous (19,33). Also, these values should only be used for the assay with which they were standardized, as interconversion of activity from one method to another for the same enzyme may often lead to marked errors. For instance, it is not recommended that alkaline phosphatase expressed in Bodansky units be multiplied by a factor to convert it to the units of the Ring-Armstrong method, or any other method for that matter. 

However, it has been established that an intense control of certain variables may improve the execution of a hydraulic fracturing job and the success of a stimulation. Therefore an intense quality control is recommended [552,553]. Such a program includes monitoring the breaker performance at low temperatures and measuring the sensitivity of fracturing fluids to variations in crosslinker loading, temperature stabilizers, and other additives at higher temperatures. 

The underlying calibration procedure of a newly developed analytical method has to be examined by basic validation studies to determine the reliability of the method and its efficiency in comparison with traditional methods. In order to ensure long-term stability, it is necessary to perform revalidations, which can be combined with the use of quality control charts, over meaningful time periods. 

Hardness does not produce a complete characterization of the strengths of materials, but it does sort them in a general way, so it is very useful for quality control for the development of new materials and for developing prototypes of devices and processes. Furthermore, mechanical hardness is closely related to chemical hardness, which is a measure of chemical bond stability (reactivity). In the case of metals the connection is somewhat indirect, but nevertheless exists. 

GFAAS end analysis of Pb in blood was critically discussed in a review, including methods of introducing the sample into the furnace, matrix interferences and ways of improving the precision of the method, such as use of a stabilized temperature platform40. An evaluation program was carried out for quality control materials and proficiency for... 

Any decision to establish automated or robotic systems must carefully consider prerequisites such as the annual numbers of samples to be processed to achieve an acceptable cost-to-benefit ratio. Late phase development stability studies may benefit from fully automated systems based on the enormous numbers of samples to be analyzed for each stability time point. The use of automated systems in manufacturing quality control is now required due to the sheer number of samples to be... 

Independent of existing intra-lot variability, a sample size of six dosage units is generally recognized to suffice the needs of quality control (QC). In very early development less than six specimens may be used to create data, but as soon as possible tests should be run with at least n = 6. It is advisable to create statistically valid and sound data for manufacturing prototypes even at very early phases of development, in order to be able to identify formulations/batches with unwanted dissolution behavior. In the early phases of a drug product s development, formulations may not be of acceptable stability. This means that stability phenomena may mask... 

Because of their considerable commercial importance, the composition and stability of anthocyanin-rich extracts have also been investigated [264], The SEC and HPLC techniques described above were employed for the analysis of four solid and four liquid commercial anthocyanin-rich extracts. The results of SEC and HPLC measurements are compiled in Table 2.92 and Table 2.93, respectively. The measurements indicated that various chromatographic techniques provide useful information on the quality of commercial anthocyanin-rich extracts and they can be successfully applied for the quality control of this class of products [265],... 

Final methods are developed for transfer to operational quality control (QC) laboratories for the release testing of production batches. Additionally, the methods are intended to be applied during Registration Stability studies and for the release of the DP or DS validation batches during the pre-approval development stage. The analytical methods should last for the entire product lifetime therefore, the aim of final method development is to generate fast, robust, reliable, and transferable HPLC methods (preferably isocratic and at low cost). 

Once the solution stability has been determined, a storage period should be determined based on the use of the method under real-world conditions. Data may show a standard solution to be very stable for 6 months at room temperature, but a quality control (QC) lab may not want to use this solution for such a long time. 

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