Abstract: This invention relates to a process for the preparation of a controlled release pharmaceutical composition comprising two discrete zones wherein the first discrete zone comprises therapeutically effective amount of pseudoephedrine or its pharmaceutically acceptable salt as active ingredient and the second discrete zone comprises a therapeutically effective amount of a long-acting antihistamine selected from the group consisting of loratadine, azatidine, fexofenadine, terfenadine, cetirizine, astemizole, and levocabastine, or their pharmaceutically acceptable salt as active ingredient.

Abstract: A pharmaceutical composition in the form of tablets or capsules provides a combination of temporal and spatial control of drug delivery to a patient for effective therapeutic results. The pharmaceutical composition comprises a drug, a gas generating component, a swelling agent, a viscolyzing agent, and optionally a gel forming polymer. The swelling agent belongs to a class of compounds known as superdisintegrants (e.g., cross-linked polyvinylpyrrolidone or sodium carboxymethylcellulose). The viscolyzing agent initially and the gel forming polymer thereafter form a hydrated gel matrix which entraps the gas, causing the tablet or capsule to be retained in the stomach or upper part of the small intestine (spatial control). At the same time, the hydrated gel matrix creates a tortuous diffusion path for the drug, resulting in sustained release of the drug (temporal control). A preferred once daily ciprofloxacin formulation comprises 69.9% ciprofloxacin base, 0.34% sodium alginate, 1.03% xanthan gum, 13.

Abstract: A drained cathode cell for the electrowinning of aluminium comprises a cell bottom (20) arranged to collect product aluminium and thermic insulating sidewalls (40) lined with a molten electrolyte resistant sidewall lining (50), in particular containing silicon carbide, silicon nitride or boron nitride. The thermic insulating sidewalls (40) inhibit formation of an electrolyte crust on the lining (50), whereby the lining (50) is exposed to molten electrolyte. The cell bottom (20) has a peripheral zone from which the insulating sidewalls (40) extend generally vertically to form, with the cell bottom, a trough for containing molten electrolyte and aluminium produced on at least one drained cathode (32). The peripheral zone of the cell bottom (20) is arranged to keep the product aluminium from contacting and reacting with the molten electrolyte resistant sidewall lining 50).

Abstract: A non-carbon, metal-based slow-consumable anode of a cell for the electrowinning of aluminium self-forms during normal electrolysis an electrochemically-active oxide-based surface layer (20). The rate of formation (35) of the layer (20) is substantially equal to its rate of dissolution (30) at the surface layer/electrolyte interface (25) thereby maintaining its thickness substantially constant, forming a limited barrier controlling the oxidation rate (35). The anode (10) usually comprises an alloy of iron with at least one of nickel, copper, cobalt or zinc which during use forms an oxide surface layer (20) mainly containing ferrite.

Abstract: There is described a process for the preparation of cefuroxime from predominantly S-cefuroxime axetil, R, S mixture of cefuroxime axetil or R-cefuroxime axetil not meeting the purity criteria. This comprises treating cefuroxime axetil with alkoxides in the presence of a suitable solvent or solvent mixture and isolating cefuroxime from the reaction mixture.

Abstract: An open-pored body (11), in particular a carbon component of an aluminum production cell, which is to be exposed to oxidizing conditions or chemical attack at high temperatures is treated to protect the body against oxidation or corrosion at high temperature by impregnating the surface of the body at about ambient temperature with a hot non-saturated liquid (10). This liquid contains a treating agent at a temperature above the temperature of the body. The concentration of treating agent in the hot liquid is such that when the liquid is cooled, before it reaches the temperature of the body, the liquid saturates and treating agent precipitates. A pressure differential is applied to cause the liquid to impregnate into the surface pores of the body (11) and precipitate a layer of the treating agent from the liquid inside the body by cooling as it impregnates the pores of the body.

Abstract: The present invention relates to the preparation of crystalline (Z)-2-(2-tert.-butoxycarbonyl prop-2-oxyimino)-2-(2-triphenylmethylaminothiazol-4-yl) acetic acid of the following formula which is useful in the synthesis of &bgr;-lactam antibiotics such is ceftazidime.

Abstract: A carbon body, in particular a prebaked anode of an electrolytic cell for the production of aluminum by the electrolysis of alumina in a molten fluoride electrolyte, is treated over its surfaces to improve the resistance thereof to deterioration during operation of the cell by air and oxidizing gases released at the anode, by immersing the body in a treating liquid containing a soluble boron compound and at least one additive from the group consisting of aluminum compounds, calcium compounds, sodium compounds, magnesium compounds, silicon compounds, elemental carbon, and elemental aluminum, said additive being in the form of a powder, in suspension such as a colloid, or in solution, e.g., at 80° to 120° C. The same treatment can also be applied to a carbon mass forming a Söderberg anode and to cell sidewalls. The additives increase strength and improve oxidation resistance compared to impregnation with boric acid alone.

Abstract: A component of an aluminium production cell, in particular a cathode or a cell lining of an electrolytic cell for the production of aluminium by the electrolysis of alumina in cryolite, having an aluminium-wettable refractory coating on a heat-stable baked carbon-containing body, is produced from a part-manufactured cell component which is a layered composite of two precursors. A precursor layer of the aluminium-wettable refractory coating contains at least one aluminium-wettable refractory material in particulate form, or a particulate micropyretic reaction mixture which when ignited reacts to form at least one aluminium-wettable refractory material, or a mixture thereof, and non-carbon fillers and binders. A non-baked or part-baked precursor of the heat-stable carbon-containing body comprises particulate carbon compacted with a heat-convertible binder which when subjected to heat treatment binds the particulate carbon into the heat-stable carbon-containing body of the fully-manufactured cell component.

Abstract: A non-carbon, metal-based anode (10) of a cell for the electrowinning of aluminium, comprising an electrically conductive, high temperature resistant and oxidation resistant metal structure (11) in the form of a wire mesh or net, a foraminate sheet, a fibrous network, a reticulated skeletal structure, or a porous structure having voids, recesses and/or pores which are filled or partly filled with an electrochemically active filling (12), such as oxides, oxyfluorides, phosphides, carbides, cobaltites and cuprates making the surface of the anode (10) conductive and electrochemically active for the oxidation of oxygen ions present at the anode surface/electrolyte (5) interface.

Abstract: An insulation material which is substantially free of fibers and which has a density of less than about 2.5 g/cc and a thermal conductivity of less than about 5 W/Km is formed from a composition comprising at least about 2%, by weight, carbon. The insulation material is resistant to thermal shock and is easily machined.

Abstract: A non-carbon, metal-based high temperature resistant anode of a cell for the production of aluminium has a metal-based substrate coated with one or more electrically conductive adherent applied layers, at least one electrically conductive layer being electrochemically active. The electrochemically active layer contains one or more electrocatalysts fostering the oxidation of oxygen ions as well as fostering the formation of biatomic molecular gaseous oxygen to inhibit ionic and/or monoatomic oxygen attack of the metal-based substrate. The electrocatalyst can be iridium, palladium, platinum, rhodium, ruthenium, silicon, tin, zinc, Mischmetal oxides and metals of the Lanthanide series. The applied layer may further comprise electrochemically active constituents from oxides, oxyfluorides, phosphides, carbides, in particular spinels such as ferrites.

Abstract: A method of producing a self-sustaining body of refractory boride from the group consisting of the borides of titanium, chromium, vanadium, zirconium, hafnium, niobium, tantalum, molybdenum and cerium. This body includes a refractory boride and a dried colloid from the group consisting of colloidal alumina, silica, yttria, ceria, thoria, magnesia, lithia, monoaluminium phosphate and cerium acetate and is obtained from a slurry of the refractory boride in one or more of said colloids by casting the slurry on a porous plaster layer, and drying the cast slurry by draining through the plaster, or by pressing/drying. Subsequently, the dried body is subjected to heat treatment to bond the refractory boride in the dried colloid. The bodies are useful as components of aluminium electrowinning cells.

Abstract: High emissivity molybdenum silicide-containing ceramic and metal-ceramic products are provided, especially for use as heaters in rapid solidification processing (RSP) and rapid thermal processing (RTP). Novel designs incorporating such heaters are also provided.

Abstract: An electrolytic cell for the electrowinning of aluminium from alumina dissolved in a halide-containing molten electrolyte, has a cathode cell bottom made of a series of carbon cathode blocks (10) connected side-by-side by glue or ramming paste, each one provided with steel or other conductive bars (11) for the delivery of current and a series of anodes (15) facing the cathode cell bottom. The tops of the carbon blocks (10) forming the cathode cell bottom are shaped in such a way as to provide in the cell bottom a series of parallel channels (25) or grooves preferably coated with an aluminium-wettable refractory coating (35) covered in use by a pool (40) of molten aluminium or a layer of molten aluminium forming a drained surface. Movement of the aluminium pool (40) is decreased, cell operation improved and cell life extended.

Abstract: Novel piperzine derivatives substituted on one nitrogen by an aromatic system and on the other nitrogen by (2,5-dioxopyrrolidin)-1-yl) alkanes or (2,6-dioxopiperidin-1-yl) alkanes have been found to exhibit selective .alpha..sub.1A adrenergic activity. The compounds are useful for treatment of disease conditions, such as peripheral vascular disease, congestive heart failure, hypertension and especially benign prostatic hypertrophy.

Abstract: Novel piperzine derivatives substituted on one nitrogen by an aromatic system and on the other nitrogen by (2,5-dioxopyrrolidin)-1-yl) alkanes or (2,6-dioxopiperidin-1-yl) alkanes have been found to exhibit selective .alpha..sub.1A adrenergic activity. The compounds are useful for treatment of disease conditions, such as peripheral vascular disease, congestive heart failure, hypertension and especially benign prostatic hypertrophy.

Abstract: A composite, high-temperature resistant, non-carbon metal-based anode of a cell for the electrowinning of aluminium comprises a metal-based core structure of low electrical resistance, for connecting the anode to a positive current supply, coated with a series of superimposed, adherent, electrically conductive layers. These layers consist of at least one layer on the core structure constituting a barrier substantially impervious to monoatomic oxygen and molecular oxygen; one or more intermediate, protective layers on the oxygen barrier layer which remain inactive in the reactions for the evolution of oxygen gas; and an electrochemically active layer for the oxidation reaction of oxygen ions present at the anode/electrolyte interface into nascent monoatomic oxygen, as well as for subsequent reaction for the formation of gaseous biatomic oxygen.

Abstract: A pharmaceutical composition in the form of a tablet or a capsule for the controlled release of diltiazem, comprises about 30 to about 97% by weight of a hydrophilic polymer, about 0.5 to about 30% by weight of an enteric (pH-dependent) polymer, and about 2.5 to about 60% by weight of diltiazem or a pharmaceutically acceptable salt or ester thereof. The ratio of hydrophilic polymer to enteric polymer is in the range of about 1:1 to about 15:1. Such a pharmaceutical composition releases diltiazem at a rate that allows effective plasma levels of diltiazem to be maintained over a period of twenty-four hours after administration to human adult subjects.

Abstract: A process for preparing cefuroxime axetil in substantially amorphous form comprises forming a mixture of crystalline cefuroxime axetil and at least one pharmaceutically acceptable excipient, and subjecting the mixture to milling for a period of time sufficient to convert the crystalline cefuroxime axetil to substantially amorphous form, i.e., the crystallinity is less than 5%. The amorphous cefuroxime axetil has a chemical purity of at least 95%. Desirably, the particles of the milled material are reduced to a size of less than 2 .mu.m. The amorphous cefuroxime axetil prepared by this method may consist of R isomer, S isomer, or a racemic mixture of the R and S isomers.