Lyophilization

Rate effects may not be chemical kinetic ones. Benson and co-worker [84], in a study of the rate of adsorption of water on lyophilized proteins, comment that the empirical rates of adsorption were very markedly complicated by the fact that the samples were appreciably heated by the heat evolved on adsorption. In fact, it appeared that the actual adsorption rates were very fast and that the time dependence of the adsorbate pressure above the adsorbent was simply due to the time variation of the temperature of the sample as it cooled after the initial heating when adsorbate was first introduced. 

Lymphoid cells Lymphomas Lymphosarcoma Lyochrome Lyophilization... 

Sterile Filtration of Gases. Primary appHcations for sterile gas filtration are the sterilization of fermentor inlet air, fermentor vent gas, vents on water for injection tanks, and vacuum break filters during lyophilization. Operational and process considerations apply. Typically, the membrane in gas... 

Purified hGH is a white amorphous powder in its lyophilized form. It is readily soluble (concentrations >10 mg/mL) in dilute aqueous buffers at pH values above 7.2. The isoelectric point is 5.2 (3) and the generally accepted value for the extinction coefficient at 280 nm is 17,700 (Af-cm) (4),... 

Lyophilization. LyophiLization is essentially a drying technology. Some dmgs and biologicals are thermolabile and/or unstable in aqueous solution. Utilization of freeze drying permits the production of granules or powders that can be reconstituted by the addition of water, buffered solution, or mixed hydrophilic solvents just prior to use, eg, certain antibiotic suspensions. 

Clinical Use. Vancomycin and teicoplanin as fomiulated dmgs are lyophilized powders to be reconstituted with sterile water for injection. Vancomycin hydrochloride [1404-93-9] is presented in vials of 500 mg that give 100—200 mL solution of pH 2.5—4.2. It is administered by slow (60 min) infusion at a dose of 500 mg every 6 h or 1 g every 12 h/d. The teicoplanin contains the five factors (87%) plus 13% of the pseudoaglycone T-A3-1. It is presented in vials containing 200 mg of lyophili ed power that after dissolution with 3 mL of solvent gives a solution at pH 7.5. The dose regimen is 200—800 mg/d by iv bolus adrninistration. 

Kits. Kits for the preparation of radiopharmaceuticals are a convenient solution to synthesis of products containing short-Hved radionucHdes (eg, In, I, Tc) bound to a nonradio active moiety. The labeling step is performed either at a commercial radiopharmacy, or within the institutional nuclear medicine laboratory. The kits are usually stored as a frozen solution or lyophilized product. The material of interest is then metered out into kit dosages. The kit vials are thawed or reconstituted and mixed with the appropriate radionucHde. 

Many kits contain the indicated biologically active ingredient in a lyophilized form with stannous chloride. A Tc-labeled radiopharmaceutical, which can be used for six hours, is formed when mixed with Tc pertechnetate. Preparation of the agent is at room temperature, unless otherwise stated. Technetium-99m. Available Tc kits are Hsted below. 

Technetium-9 9m sestamibi is used in myocardial perfusion imaging for the evaluation of ischemic heart disease. It is prepared from a lyophilized kit containing tetrakis(2-methoxy isobutyl isonittile) copper(I) tetrafluoroborate stored under nitrogen. Upon reconstitution with up to 5.6 GBq (150 mCi) of 99mTc pertechnetate, the product is formed by boiling for 10 minutes. 

Technetium-99m oxidronate is a bone imaging agent used to demonstrate areas of altered osteogenesis. It is rapidly cleared from the blood and taken up in areas of bone that are undergoing osteogenesis. The kit is a vial containing a lyophilized powder where sodium oxidronate is the active... 

General trends in radiopharmaceutical research emphasize the use of small peptides. These molecules, of which the agents mentioned for thrombosis localization are an example, exhibit rapid and specific binding, and rapid blood clearance, two important parameters for a successflil radiopharmaceutical. Peptides are readily labeled with Tc and lend themselves to formulation as lyophilized kits that can be rapidly and rehably reconstituted. Possible targets for these molecules are quite varied, ranging from atherosclerotic plaque to P-amyloid (for Alzheimer s disease), to a variety of somatic receptors the populations of which are increased or decreased in disease. 

Drying is an operation in which volatile Hquids are separated by vaporization from soHds, slurries, and solutions to yield soHd products. In dehydration, vegetable and animal materials are dried to less than their natural moisture contents, or water of crystallization is removed from hydrates. In freeze drying (lyophilization), wet material is cooled to freeze the Hquid vaporization occurs by sublimation. Gas drying is the separation of condensable vapors from noncondensable gases by cooling, adsorption (qv), or absorption (qv) (see also Adsorption, gas separation). Evaporation (qv) differs from drying in that feed and product are both pumpable fluids. 

Activase 550/20 mg Thrombolytic encymes lyophilized recombinant tPA Genentech... 

Freeze drying, or lyophilization, is normally reserved for temperature-sensitive materials such as vaccines, enzymes, microorganisms, and therapeutic proteins, as it can account for a significant portion of... 

Two complexes of FeCl, with NH OH were received in crystalline state-one-brown by precipitation from the solution (HI) and pink-brown compound was received by lyophilic drying of the solution (IV). 

Reaction of alkali cellulose with carbon disulphide to produce a cellulose xanthate which forms a lyophilic sol with caustic soda. This may be extruded into a coagulating bath containing sulphate ions which hydrolyses the xanthate back to cellulose. This process is known as the viscose process and is that used in the manufacture of rayon. 

Potential ionic interactions may also be provided by the free amine groups of the arginine fragment. As a consequence, the net character of the heptapeptide will be polar, and the peptide would be classed as hydrophilic or lyophilic in nature. 

---