Raw materials quality

The advance of sulfur trioxide as sulfating agent largely depended on advances in sulfonation/sulfation reactor development and changes in raw material quality. Undiluted sulfur trioxide cannot be used as a sulfating agent except in special cases where suitable equipment is used because of its violent nature. Sulfur trioxide diluted in an inert gas, usually air, when used in batch processes can cause excessive dehydration and dark-colored products. However, batch processes were used years ago and inert liquid solvents were often suggested or used to moderate the reaction. Inadequate reaction conditions lead to a finished product that can contain dialkyl sulfate, dialkyl ether, isomeric alcohols, and olefins whereas inadequate neutralization conditions can increase the content of the parent alcohol due to hydrolysis of the unstable acid sulfate accompanied by an increase of mineral sulfate. 

Dioxane forms by the chemical cleavage of two molecules of ethylene oxide from the parent ethoxylated alcohol. Dioxane is the undesirable byproduct. The amount of dioxane ranges from traces to hundreds, even thousands, of ppm (mg/kg) depending on raw material quality and sulfonation/neutralization process conditions. 

The raw material quality variations have a high impact on the schedule itself, as also the time for logistics (e.g., crane movements) has to be taken into account and... 

Raw material quality control records Retained sample documentation Quality control (qc) lab logs Emergency responder logs... 

Known Variables - Uncontrollable or Controllable Within Limits A long series of experiments sometimes involves situations where variation due to changes in one or more factors is known to exist, but where these factors cannot be completely controlled. An example is raw-material quality. Different lots of raw material or catalyst used in an experimental programme may sometimes vary in chemical composition, impurities, activity, etc. Since these items may not be within the control of the user and may not easily be worked into a balanced experimental design, the differences should at least be recorded and their effect taken into consideration during the analysis... 

Even though full GMP compliance may begin later than receipt of raw materials, it is important to treat raw materials in a GMP compliant manner. Raw materials should be purchased only from suppliers approved by the Quality Unit. For raw materials whose quality is important to conformance of the excipient to compendial or specification requirements, or to performance expectations, the supplier approval process should be a combination of site visit and an evaluation of raw material quality. For other raw materials, it would be adequate to confirm that the raw material supplier can meet the purchasing specification. 

Material property specifications must be written by design and material engineers to control engineering requirements and to control incoming raw material quality. Material property requirements depend on various in-use functional needs in terms of electrical, mechanical, thermal, chemical, optical, and magnetic properties. 

Kosinski, E. 1996. Raw material quality. Bulletin 315, pp. 12-16, International Dairy Federation, Brussels. 

In addition to oxidation losses-by the above four mechanisms, mechanical carbon loss (dusting) also occurs due to uneven oxidation of the anode surface. Furthermore, a variety of other factors, related to anode fabrication and use, can affect carbon consumption. The most important of these factors are (1) raw material quality,... 

Distillates from coal tar (carbochemical oils), or residual oils that are created by catalytic cracking of mineral oil fractions and olefin manufacture by the thermal cracking of naphtha or gas-oil (petrochemical oil) can also be used as a source of raw material. Quality is the main criteria to favor a specific feedstock. Here a variety... 

Numerous publications (10 to 12) have appeared, principally from the GDR, on the required quality properties of brown coal and their influence on the quality characteristics of formed coke. Since the Rheinische Braunkohlenwerke AG is not engaged in formed coke production at present, raw material quality and coking behaviour are of interest only for the production of fine coke using the rotary hearth furnace (13> 14). 

The deformation properties of the drug substance and excipients will have a direct influence on the strength of the tablets that are produced by direct compression. The type of deformation that occurs will depend upon the material s inherent properties and the amount of force being applied. Deformation can be described in three main ways elastic, plastic, and brittle fragmentation, but it is important to realize that these are idealized deformation mechanisms— most real materials are some combination of two or all three mechanisms. Processes such as wet granulation, melt extrusion, and roller compaction can be used to improve compaction properties and reduce formulation sensitivity to changes in raw material quality. 

There are several definitions of validation but, in simple terms, the word means demonstrating that a process will consistently produce the results that it is intended to. Thus, with respect to sterile products, validation would be necessary for each of the individual aspects of the manufacturing process, e.g. environmental monitoring, raw materials quality assessment, the sterilization process itself and the sterility testing procedure. Of these, it is the sterilization process that is likely to be subject to the most detailed and complex validation procedures, and these will be used to exemplify the factors to be considered. A typical validation procedure for a steam sterilization process is likely to incorporate most, or all, of the following features ... 

Maelkki Nikkilae, Aalto and Heinonen [31, 32] stress the importance of the raw material quality of onions. Stieger [33] has investigated the suitablity of various strawberry varieties. Processes for flavour preservation have been thoroughly examined with cultivated mushrooms, leading to an illumination of the most important freeze drying parameters [34[. 

Bucheli P., Meyer I., Pittet A., Vuataz G. and Viani R. (1998) Industrial storage of green robusta coffee under tropical conditions and its impact on raw material quality and ochratoxin A content. J Agric. Food Chem. 46, 4507-11. 

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