Abstract: The present invention relates to an aqueous oral composition comprising: a) from 0.2% to 3% divalent metal ions comprising: i. from 0.1% to 1.5% of zinc ions; ii. from 0.1% to 2% of tin (II) ions; and b) a source of fluoride ions; c) a silica dental abrasive; d) one or more chelants having a MW of less than 1000 and capable of forming water-soluble complexes with the zinc ions, wherein the chelants comprise less than 0.2% linear polyphosphates having a chain length of four or more; e) an orally acceptable carrier comprising at least 20% total water; wherein the pH of the composition is from 5 to 6.5, the molar ratio of the chelants to the divalent metal ions is at least 0.70:1 and at least 80% by weight of the total zinc ions are solubilised within the composition. The composition of the invention has been found to give improved antimicrobial activity from the zinc/stannous combination without significant taste, staining or stability problems, compared to compositions having lower levels of chelants.

Abstract: The present invention relates to an oral composition comprising, in an orally acceptable carrier, from about 0.1% to about 5% zinc oxide; and from about 0.1% to about 5% of a source of carbonate ions selected from alkali metal and ammonium carbonates and bicarbonates. The molar ratio of carbonate ion to zinc ion is from about 0.05:1 to about 1:1. The composition has good antiplaque efficacy and taste. Preferred compositions are toothpastes.

Abstract: The present invention relates to an aqueous oral composition comprising: a) from 0.2% to 3% divalent metal ions comprising: i. from 0.1% to 1.5% of zinc ions; ii. from 0.1% to 2% of tin (II) ions; and b) a source of fluoride ions; c) a silica dental abrasive; d) one or more chelants having a MW of less than 1000 and capable of forming water-soluble complexes with the zinc ions, wherein the chelants comprise less than 0.2% linear polyphosphates having a chain length of four or more; e) an orally acceptable carrier comprising at least 20% total water; wherein the pH of the composition is from 5 to 6.5, the molar ratio of the chelants to the divalent metal ions is at least 0.70:1 and at least 80% by weight of the total zinc ions are solubilised within the composition. The composition of the invention has been found to give improved antimicrobial activity from the zinc/stannous combination without significant taste, staining or stability problems, compared to compositions having lower levels of chelants.

Abstract: The present invention relates to an oral composition comprising, in an orally acceptable carrier, from about 0.1% to about 5% zinc oxide; and from about 0.1% to about 5% of a source of carbonate ions selected from alkali metal and ammonium carbonates and bicarbonates. The molar ratio of carbonate ion to zinc ion is from about 0.05:1 to about 1:1. The composition has good antiplaque efficacy and taste. Preferred compositions are toothpastes.

Abstract: An electrostatic spraying device for use in spraying inter alia personal care and personal hygiene products comprises an outlet (94) from which the product issues in the form of an electrostatically charged spray and a control member (60, 60a) for attenuating the potential gradient in the vicinity of the outlet (94) to such an extent that spraying is suppressed until the device is brought to within a predetermined distance from a site to be spayed.

Abstract: An electrostatic spraying device comprising a nozzle, means for establishing a column of material to be sprayed within a passage leading to the nozzle outlet such that the leading surface of the column is spaced from the nozzle outlet, means for pneumatically ejecting said column or part thereof from the nozzle and means for applying high voltage to the material so that the spray formed by breaking up of the column on ejection from the nozzle are electrically charged. The column of material in the passage is preferably a discreet slug having a leading surface spaced from the nozzle outlet and a trailing surface to which air, gas or vapor under pressure can be applied to effect ejection of the slug from the nozzle.

Abstract: A method and device (20) for spraying particulate materials in which a high voltage is applied to a mass of the particulate material so as to cause particles to issue from the mass. High voltage from a source (16) is applied to a mass of material (36) stored in a container. A surface of the mass (36) is exposed to the surroundings and the applied voltage is conducted through the bulk material to particles located at the exposed surface which are thereby projected as an electrically charged spray from the mass under the influence of the electric field substantially without any accompanying corona discharge.

Abstract: An electrostatic spraying device comprising a high voltage generating circuit powered by a low voltage circuit comprising one or more radiation sensitive elements and charge storage means.

Abstract: An electrostatic spraying device is disclosed which is suitable for, but not limited to, dispensing an electrostatically sprayable substance for nasal or oral inhalation. Electrical charge is imparted to the spray particles by applying a high voltage to the substance prior to break up into a spray. In one embodiment, the device includes a nozzle portion for registry with the nasal or oral cavity and defines a passageway through which, in use, air can be drawn by inhalation on the part of the user. The substance to be sprayed passes into the passageway so that, with the assistance of user-induced air flow through the passageway, the resulting spray passes into the oral or nasal cavity.

Abstract: A high voltage generator is provided for use in applications where current demand is low but a high voltage is required. The generator comprises an array of photosensitive elements, such as an array of photovoltaic elements produced by laser scribing or etching of a wafer of material conventionally used for solar cells, the number of elements employed and their interconnection being such that a high voltage output of at least 1 kV is obtained.

Abstract: The present invention provides an electrostatic spraying device which includes a primary charge return path between the device and the target to be sprayed and circuitry for warning the operator of potentially hazardous spraying conditions. More particularly, the present invention includes circuitry for warning the operator of conditions wherein the primary charge path is inadequate and other conditions in which the return of spray current via the primary charge path is affected.

Abstract: An electrostatic spraying device is disclosed having a container (16) for the liquid to be sprayed and a capillary structure (22) extending into the container. To maintain a substantially constant liquid level at the location where liquid is drawn into the capillary structure, the container is partitioned into two chambers, one (68) of which is isolated from atmosphere and the other (66) of which is in communication with atmosphere. The capillary structure (22) extends through one chamber and the arrangement is such that the liquid level at the location where the capillary structure communicates with the liquid is maintained substantially constant over a wide range of variation of the liquid level within the other chamber. The upper end of the capillary structure may be provided with an oblique end face (50; 70, 72) to facilitate dispersal of the spray into the surroundings.

Abstract: An electrostatic spraying device for spraying liquids comprises a hollow capillary structure having a convoluted inner surface, one end of which contacts a reservoir of an electrostatically sprayable liquid preferably having a viscosity from 1 to 20.times.10.sup.-6 m.sup.2 /s and a volume resistivity from 2.5.times.10.sup.6 to 5.times.10.sup.8 ohm cm, the other end of which terminates in an atomization tip, and means for applying high voltage to the liquid in order to cause the liquid at the atomization tip to break up into a plurality of electrostatically charged droplets. Cartridges for use in the electrostatic spraying device are also described.

Abstract: An electrostatic spraying device for use in spraying liquids having resistivities of the order of 5.times.10.sup.6 ohm.multidot.cm and viscosities of the order of 1 Poise at a spraying rate up to at least 4 cc/min (especially paint formulations) is provided with an annular shroud (112) of semi-insulating material (e.g. bulk resistivity of the order of 10.sup.11 to 10.sup.12 ohm.multidot.cm) which is electrically connected to a high voltage generator (126) for supplying high voltage to liquid emerging at the outlet of the nozzle (114). In this way, a voltage is established on the annular electrode (126) which is of the same polarity, and substantially the same magnitude, as the voltage applied to the liquid thereby modifying the potential gradient in the immediate vicinity of the nozzle outlet so as to allow the use of the high voltage needed to effect efficient spraying of liquids having the specified resistivity and viscosity at flow rates up to at least 4 cc/min.

Abstract: A novel semiconductor switching device for use in high voltage applications (typically ranging from 5 kV up to about 50 kV) makes use of the well-known effect of reverse conduction in silicon diodes when exposed to light. Hitherto, photodiodes have been commercial available for relatively low voltage applications. The device disclosed herein is implemented by a high voltage diode having a series of semiconductor junctions and a light emitting diode operable to irradiate the junctions to render the high voltage diode conducting in the reverse bias direction. The switching device finds application in electrostatic spraying devices where the current demands are relatively small, eg up to about 2 .mu.A.