Freeze-drying product preparation

Figure 13.5 Outline of the production strategy of CEA-SCAN. The antibody-producing hybridoma cell line was originally obtained by standard methods of hybridoma generation. Spleen-derived murine B-lymphocytes were fused with murine myeloma calls. The resulting stable hybridomas were screened for the production of anti-CEA monoclonals. The clone chosen produces an IgG anti-CEA antibody. Note that the finished product outlined above is not radiolabelled. The freeze-dried antibody preparation (which has a shelf life of 2 years at 2-8 °C) is reconstituted immediately prior to its medical use. The reconstituting solution contains 99mTc, and is formulated to facilitate direct conjugation of the radiolabel to the antibody fragment...

It is likely asked too much of most laboratory plants, if used as pilot plants for production process development. The best application of laboratory plants is the freeze drying of preparations and products which do not require to be operated within small tolerances, but can be dried under noncritical process data. 

Critical Steps in the Preparation of Elastomeric Closures for Biopharmaceutical Freeze-Dried Products... 

Rubber for closures for containers for aqueous parenteral preparations and for powders for freeze-dried products. In European Pharmacopoeia, 3rd Ed. European Pharmacopoeia Commission Strasbourg, France, 1996Section 3.1.12 in 1999 Addendum. 

Although viruses from different animal species (e.g., porcine, canine, and bovine) were used to test the terminal freeze dry/dry heat treatment of the Koate -DVI, Replenate , and Liberate processes, the differences in parvovirus reduction and product recovery were probably due to the different formulations and freeze drying cycles of all three FVIII products. For freeze dried products, formulation and the freeze drying process are interrelated. Without the appropriate buffers and stabilizers or optimal temperatures and cycle times, many protein preparations would be denatured by the physical stresses associated with the freeze dry/dry heat treatment. 

Finished mixtures for the food sector are often prepared with powdered flavourings. Especially if natural finished flavourings are called for, the use of freeze-dried products should be taken into consideration. The dry matter of a natural extract contains carbohydrates, proteins and other nitrogen compounds, fats and waxes, minerals, vitamins, acids and flavouring substances, which all have an impact on the drying behaviour. 

Adsorption isotherms of potatoes were of sigmoid shape and were affected by drying method, tanperature, and addition of sugar [85]. The freeze-dried product absorbed more water vapor than the vacuum-dried materials. The sorption isotherm prepared from fresh and freeze-dried Thompson... 

Barabassy and Turza (4), using the same set of samples, studied the influence of the lyophilization process on spectral response, by taking reflectance spectra of the mixed powders as prepared and after reconstitution and lyophilization. The SEC increased by more than three times after lyophilization, also showing a calibration range double that before lyophilization, most likely because of residual water in the freeze-dried products. In protein determination the SEC increased from 1.89% to 2.772% after lyophilization, and for fat the SEC increased from 0.128% to 0.166%. The authors concluded that the accuracy obtained was acceptable for industrial practice. The use of NIR spectroscopy in milk powder evaluation could be extended also to applications for classification purposes. 

Each interferon preparation was ultracentrifuged at 20,000 revolutions per minute for one hour to remove tissue debris and inactivated virus. The supernatant was dialyzed against distilled water (1 400) for 24 hours at4°C. The material was then freeze-dried. The dried product was reconstituted in one-tenth of the original volume in distilled water and dispensed into ampoules. Reconstituted solutions were assayed for interferon activity, examined for toxicity, and tested for sterility. 

Native, multi-subunit KLH also should not be frozen. Freeze-thaw effects cause extensive denaturation and result in considerable amounts of insoluble material. Commercial preparations of native KLH are typically freeze-dried solids that no longer fully dissolve in aqueous buffers and do not display the protein s typical blue color due to loss of chelated copper. The partial denatured state of these products often makes conjugation reactions difficult. 

Materials. Na-Kaolinite A homoionic sample of kaolinite was prepared from a well-crystallized sample purchased from Source Clays, University of Missouri, using a standardized technique (14) which involved repeated washing with distilled water and by treatment with NaCl solutions to remove exchangeable ions such as Ca, and freeze-drying of the final product. Nitrogen specific surface area of this kaolinite was estimated to be 9.4nr/g and X-ray analysis showed the characteristic pattern of kaolinite. 

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