In a process for coating tapes or sheets with viscous solutions by the air-brush principle, a steam of air flows in the opposite direction to the movement of the web of material and acts substantially tangentially on the formation of the coating. This steam of air is produced by a vacuum between a bar which has an edge in the form of a ruler edge and the tape which is being coated, which moves past it at a close distance.
An apparatus is provided for coating web-form substrates, the apparatus consisting of a coating roller and of a coating block part of which is pivotal. The thickness of the layer coated on the substrate is determined by the interval between the coating block and the coating roller. In order to adjust this interval, to the precise value needed replaceable precision-gauge blocks corresponding in length to the required production conditions are arranged between the fixed part and the pivotal part of the coating block.
In coating a strip of material, such as web of paper, it is passed over a support member forming one of the enclosing surfaces of a closed chamber. The closed chamber is arranged to operate under vacuum conditions. Coating liquid is supplied in excess to the closed chamber to form a layer on the surface of the strip. At the end of the coating action, as the strip leaves the closed chamber, it is contacted by a movably positionable blade which provides a wiping-off action on the strip so as to remove the excess of coating liquid from the strip. The vacuum inside the closed chamber urges the blade against the strip. Therefore, it is possible, by varying the vacuum, to vary the amount of coating liquid adhering to the strip leaving the closed chamber.
The invention is directed to a biodegradable film dressing with or without additional therapeutic agents, an apparatus for spray delivery and a method for formation of the film dressing-on a human or animal tissue. The film dressing is formed from a liquid composition of at least one biodegradable/bioerodible thermoplastic polymer in a pharmaceutically acceptable solvent. The spray apparatus includes a vessel containing the liquid composition with a dispensing means. The film is formed by dispensing, preferably by spraying, the liquid composition onto a tissue site and contacting the liquid composition with an aqueous based fluid to coagulate or solidify the film onto the human or animal tissue. The biodegradable film can be used to protect and to promote healing of injured tissue and/or to deliver biologically active agents.
The invention provides an apparatus for remote delivery of an aerosolized liquid by laparoscopic technique, a method of delivering an aerosolized liquid into the body of an animal by means of the apparatus, and a kit that contains components of the apparatus.
