A new freeze-drying technique for processing biological materials. 1976

A Briggs

Wet granulation and dry blending are standard techniques used in tablet formulation. Both techniques impose limitations on the ability to produce homogeneous tablets with rapid dissolution and controllability of the matrix for active ingredients. This report describes the development and application of a new freeze-system using a swirling bath of Freon-12 to process sensitive biological materials. The frozen beads produced with this process are subsequently freeze-dried and may be used to produce precise tablets. The ultra rapid freezing (7-14 milliseconds) provided by the Freon-12 process yiels amorphous homogeneous spheres by retarding component migration which permits precise control of pH and redox potential in the final product. Dissolution of tablets prepared by this Du Pont process is so rapid (8-12 seconds) that a special testing technique is required for measurement of dissolution time. Improved recoveries of activity have been demonstrated for sensitive biological materials compared to conventional freeze-drying. The optimization of droplet sizes is controlled by injection rate, stream diameter and surface velocity of the Freon-12 bath. Droplet size control permits attainment of weight precision in the range of 0.6 +/- 0.06% for a final 50 mg tablet. This compares with a tablet weight precision of 1% to 2% typical of dry blending and wet granulating. Potential applications of this technology include pharmaceuticals and the production of ultra precise reagent tablets for the Du Pont Automatic Clinical Analyser.

UI MeSH Term Description Entries
D005069 Evaluation Studies as Topic Works about studies that determine the effectiveness or value of processes, personnel, and equipment, or the material on conducting such studies. Critique,Evaluation Indexes,Evaluation Methodology,Evaluation Report,Evaluation Research,Methodology, Evaluation,Pre-Post Tests,Qualitative Evaluation,Quantitative Evaluation,Theoretical Effectiveness,Use-Effectiveness,Critiques,Effectiveness, Theoretical,Evaluation Methodologies,Evaluation Reports,Evaluation, Qualitative,Evaluation, Quantitative,Evaluations, Qualitative,Evaluations, Quantitative,Indexes, Evaluation,Methodologies, Evaluation,Pre Post Tests,Pre-Post Test,Qualitative Evaluations,Quantitative Evaluations,Report, Evaluation,Reports, Evaluation,Research, Evaluation,Test, Pre-Post,Tests, Pre-Post,Use Effectiveness
D005612 Freeze Drying Method of tissue preparation in which the tissue specimen is frozen and then dehydrated at low temperature in a high vacuum. This method is also used for dehydrating pharmaceutical and food products. Lyophilization,Drying, Freeze,Dryings, Freeze,Freeze Dryings,Lyophilizations
D005617 Chlorofluorocarbons, Methane A group of methane-based halogenated hydrocarbons containing one or more fluorine and chlorine atoms. Fluorocarbon Aerosols,Fluorocarbon Propellants,Chlorofluoromethanes,Aerosols, Fluorocarbon,Methane Chlorofluorocarbons,Propellants, Fluorocarbon
D001688 Biological Products Complex pharmaceutical substances, preparations, or matter derived from organisms usually obtained by biological methods or assay. Biologic,Biologic Drug,Biologic Product,Biological,Biological Drug,Biological Medicine,Biological Product,Biologics,Biopharmaceutical,Natural Product,Natural Products,Biologic Drugs,Biologic Medicines,Biologic Pharmaceuticals,Biologic Products,Biological Drugs,Biological Medicines,Biologicals,Biopharmaceuticals,Products, Biological,Drug, Biologic,Drug, Biological,Drugs, Biologic,Drugs, Biological,Medicine, Biological,Medicines, Biologic,Medicines, Biological,Pharmaceuticals, Biologic,Product, Biologic,Product, Biological,Product, Natural
D013607 Tablets Solid dosage forms, of varying weight, size, and shape, which may be molded or compressed, and which contain a medicinal substance in pure or diluted form. (Dorland, 28th ed) Tablet

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