Filter pharmaceutical processes

Aseptic compounding is often a required activity for sterile products that cannot be filter sterilized. The preparation of the sterile solids for use in these formulations is outside the scope of this chapter, but it is often acknowledged as the most difficult of all pharmaceutical processes to properly execute. Handling these materials at the fill site is performed using ISO 5 environments, and the use of closed systems is preferred [34],... 

The most important consideration in the selection of the filter is the compatibility of the hlter materials of constmction with the solvent. The solvents used in pharmaceutical processes can be very aggressive. They include acetone, methanol, ethanol, isopropyl alcohol (IPA), acetonitrile, dimethyl acetamide, dimethyl formamide (DMF), ethyl acetate, tetrahydrofuran (THF), methyl isobutyl ketone (MIBK), and methyl ethyl ketone (MEK). Filters with PTFE membranes and polypropylene supports are used in most applications. 

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. 

The trend towards elimination of hydraulics in pharmaceutical process areas has turned maintenance over to the instrumentation and electrical specialists, as variable frequency drives become the standard. The Inverting Filter Centrifuge (Heinkel) eliminates all hydraulics from the centrifuge design to satisfy increasingly stringent cleanroom requirements by pharmaceutical companies. The risk of hydraulic oil in the process area has been a concern with respect to contamination with the product. 

Errico, J.J. (1986). Validation of aseptic processing filters. In Validation of Aseptic Pharmaceutical Processes. F.J. Carleton and J.P. Agalloco (Eds), pp. 427-471. Marcel Dekker. 

Elemental phosphoms from the electrothermal process is a distilled product of high purity and yields phosphoric acid pure enough for most industrial uses without any further treatment. The main impurity is ca 20—100 ppm arsenic present in the phosphoms as the element and in the phosphoric acid as arsenious acid. To remove the arsenic, the phosphoric acid destined for food, pharmaceutical, and some industrial-grade appHcations is treated with excess hydrogen sulfide, filtered, and blown with air to strip out excess H2S. This treatment generally reduces the arsenic content of the phosphoric acid to less than 0.5 ppm. The small amount of filter cake is disposed of in approved chemical landfills. 

Phosphoms trichloride is also used in the manufacture of antifoam agents, catalysts, dyes and pigments, as well as pharmaceutical and quaternary compounds, and is commonly used as a chlorinating agent. Phosphoms trichloride is used to make phosphoms oxychloride, which is used in the manufacture of adsorbents for air filters, antifoam agents, dyes and pigments, mineral-processing materials, pharmaceuticals (qv), and solvents. These uses represented 32,000 t of PCl in 1988 and 30,000 t in 1994. 

The purpose of open unidirectional airflow benches is to protect products from particulate contaminants by creating a controlled environment. These benches are used, for example, in electronic, biological, pharmaceutical, and food industries. It should be mentioned that within pharmaceutical production, aseptic sterile processes must be carried out in a Class 100 environment (U.S. Federal Standard 209 E, Airborne Particulate Cleanliness Classes in Cleanrooms and Clean Zones). To avoid particle contamination in the bench, horizontal or vertical airflow with high-efficiency particulate air (HEPA)-filtered air is used. The air velocity is normally 0.4-0.5 ra s". Some examples of typical arrangements of open unidirectional airflow benches are shown in Fig. 10.51. 

Carbon filters find particular application as prefilters for RO and ion-exchange processes in the production of high purity FW. They are also used in clean-steam boilers and other types of steam generators where the steam is ultimately destined for application in food or beverage production, pharmaceuticals, electronics, surgical instrument sterilization, and similar processes. 

Pharmaceuticals for injection must be presented in a sterile form. Sterility may be achieved by filtration through 0.22 pm filters under aseptic conditions, or by steam, dry heat, radiation or gas sterilisation methods, which may be applied to packaged products. Irrespective of the method, the process must be validated and monitored to assure its effectiveness. As discussed in Chapter 2, this is an example of a process that cannot be assured by verification testing because of its destructive nature. 

Pharmaceutical Removal of suspended matter is a frequent application for MF. Processes may be either clarification, in which the main product is a clarified liquid, or solids recovery. Separating cells or their fragments from broth is the most common application. Clarification of the broth in preparation for product recovery is the usual objective, but the primary goal may be recovery of cells. Cross-flow microfiltration competes w l with centrifugation, conventional filtration by rotary vacuum filter or filter press and decantation. MF delivers a cleaner permeate, an uncontaminated, concentrated cell product... 

There is also often a need for clean, filtered, air for process using air as a raw material, and where clean working atmospheres are needed for instance, in the pharmaceutical and electronics industries. 

---