Water pharmaceutical process

Sterilization. In some processes, such as food and beverage and pharmaceutical processes, water might need to be sterilized before it is reused or recycled. Chemical oxidation (e.g. ozonation) can be used. Ultraviolet light is an alternative for lightly contaminated water. Alternatively, a combination of chemical oxidation and UV light can be... 

It is the objective of this chapter to discuss the various mechanisms whereby water can interact with solid substances, present methodologies that can be used to obtain the necessary data, and then discuss moisture uptake for nonhydrating and hydrating crystalline solids below and above their critical relative humidities, for amorphous solids and for pharmaceutically processed substances. Finally, transfer of moisture from one substance to another will be discussed. 

The high amounts in which these substances are consumed and produced have conferred illicit drugs and their human metabolites a pseudo-persistent character in the environment. Like over-the-counter and prescribed pharmaceuticals, illicit drugs are metabolized after consumption and different proportions of the parent compound and metabolic by-products are excreted via urine or feces and flushed into the sewage system toward wastewater treatment facilities, if existing. However, these substances are poorly or incompletely removed by conventional waste-water treatment processes [2, 3]. As a consequence, illicit drugs and metabolites are continuously introduced via wastewater treatment plant (WWTP) effluents into the aquatic media. In fact, this constitutes the main route of entry of this type of compounds into the environment as direct disposal is unlikely. 

In most cases, ointments, suppositories, ophthalmic, and parenteral products assume the color of their ingredients and do not contain color additives. In addition to esthetics and the certification status of a dye, a formulation pharmacist must select the dyes to be used in a particular formula on the basis of the physical and chemical properties of the dyes available. Of prime importance is the solubility of a prospective dye in the vehicle to be used for a liquid formulation or in a solvent to be employed during a pharmaceutical process (such as when the dye is sprayed on a batch of tablets). In general, most dyes are broadly grouped into those that are water-soluble and those that are oil-soluble few, if any, dyes are both. 

Stackelberg PE, Gibs J, Furlong ET, Meyer MT, Zaugg SD, Lippincott RL (2007) Efficiency of conventional drinking-water-treatment processes in removal of pharmaceuticals and other organic compounds. Sci Total Environ 377 255-272... 

Westerhoff P, Yoon Y, Snyder S, Wert E (2005) Fate of endocrine-disruptor, pharmaceutical, and personal care product chemicals during simulated drinking water treatment processes. Environ Sci Technol 39 6649-6663... 

Studies on conventional drinking-water treatment processes, such as filtration, coagulation and sedimentation, have shown that coagulation is largely ineffective in removing pharmaceuticals. Free chlorine is able to remove up to approximately 50% of the pharmaceuticals investigated, whereas chloramines have lower removal... 

As above mentioned, in Sect. 2.3.2, none of the wide range of drinking water treatment processes available have been designed to remove pharmaceuticals that may be present in source waters. Therefore, its worldwide presence in drinking water generates a growing concern due to the possible human exposure [52, 106, 107],... 

Table 3.7. Range of impurities found in potable water. Even extremely low levels of any such impurities renders this grade of water unacceptable for pharmaceutical processing purposes. Reproduced by permission of John Wiley Co Ltd from Walsh Headon (1994)...

The water purification process adopted by pharmaceutical industries must be able to furnish water with the quality parameters presented in Table 2. 

In summary, water can be a source of contaminants. If the raw material (drinking water) complies with the quahty parameters established by authorities, contaminants still present can be eliminated by usual water purification processes available to the pharmaceutical industry. While distillation and reverse osmosis provide water with the quality specifications for purified water and highly purified water, WFI is generally obtained by membrane filtration (associated with another purification process) not only because of chemical contamination but mainly because of sterility requirements. 

Carton, F. J., Agalloco, J. P., Artiss, D. H. Validation of Aseptic Pharmaceutical Process. Water System Validation. New York Marcel Dekker (1996). 

There has been considerable growth of interest in so-called Green Chemistry or Sustainable Chemistry over the last quarter century. The terms Green and Sustainable have given new prominence to fermentation and enzyme-mediated processes and to systems that operate in water. Such processes build on the already major contribution that fermentation processes make to the pharmaceutical industry. As an aside, several important classes of API owe their commercial success to the fermentation of microorganisms ... 

Refiigeration is needed when the required temperature is below the cooling-water temperature, such as in the production of liquid nitrogen and oxygen. Re-fngeration is also used when the material being processed is sensitive to high temperatures, such as in food and pharmaceutical processes. 

The basic approach regarding how adsorption at solid surfaces affects different aspects of pharmaceutical development, especially for solid dosage forms, is briefly reviewed. The three broad fields addressed are general pharmaceutical processing, dissolution rate enhancement for poorly water-soluble compounds, and some other applications using adsorption at solid surfaces. Case studies are introduced to aid in understanding the applications and/or principles involved. 

Historically, a classic example of an evaporation process is the production of table salt. Maple syrup has traditionally been produced by evaporation of sap. Concentration of black liquor from pulp and paper processing constitutes a large-volume present application. Evaporators are also employed in such disparate uses as desalination of seawater, nuclear fuel reprocessing, radioactive waste treatment,preparation of boiler feed waters, and production of sodium hydroxide. They are used to concentrate stillage waste in fermentation processes, waste brines, inorganic salts in fertilizer production, and rinse liquids used in metal finishing, as well as in the production of sugar, vitamin C, caustic soda, dyes, and juice concentrates, and for solvent recovery in pharmaceutical processes. 

There are a variety of different depth filter and membrane filter materials used within the pharmaceutical processes. Depth filter are fibrous materials for example, polypropylene, borosilicate, or glassfibre fleeces (Fig. 3). Borosilicate and glassfibre materials are highly adsorptive and commonly used to remove colloidal substances, like iron oxide from water or colloidal haze from sugar solutions. 

In many application scenarios such as high-pressure boilers, production of electronic components, synthesis of pharmaceuticals, etc. it is desirable to remove all the dissolved ions from the water. This process is termed demineralization. The primary use of ion exchangers is in demineralization because it can achieve the goal at low cost, and the quality is comparable to that by distillation. The process depends on two reaction... 

Reverse osmosis membrane is widely used in seawater and brackish water desalination processes. Compared to traditional distillation, there is no energy-intensive phase change involved in membrane processes. Therefore, desalination with RO membrane is more energy efficient. In addition to the traditional desalination processes, RO membranes have also found wide application in industrial and municipal wastewater treatment, in pure water production for the electronic and pharmaceutical industries, and in the food industries. 

Figure 74 shows another example of evaluation in 254-nm UV light from the area of pharmaceutical process development. Here, starting materials, in-process control, mother Uquor, wash water and the end product are monitored by TLC. With in-process control, TLC gives rapid and reliable results with an accuracy that is quite adequate for the chemical production process. 

The majority of studies on drugs and excipients involving TGA have used the technique as a means of identifying and characterizing pharmaceutical hydrates. The method presents several opportunities in this respect. In the first instance, the presence of a hydrate (as opposed to sorbed water) is usually easily discerned by the sharpness of the instrumental response corresponding to the water loss process. More specifically, loss of water of hydration usually occurs for pharmaceuticals over a range of approximately 5 to 20°C, depending on the experimental conditions used,... 

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