In an extraction apparatus for counter-current liquid-liquid extraction having several horizontally displaced extraction stages, each stage includes a mixing chamber with a mechanical mixer and further a settling basin with an auxiliary space connected to the mixing chamber through an opening or a pipe. From the upper part of each settling basin there runs a flow pipe to the upper part of the mixing chamber of the subsequent extraction stage, the lower part of the settling basin being connected to the lower part of the mixing chamber of the previous stage through said auxiliary space by connection means forming in the auxiliary space a vertically adjustable device, specifically a gooseneck pipe. Said auxiliary space may be situated within the settling basin and to the mixer of the mixing chamber there may be connected additional means promoting the flow of the heavier liquid.
Mixer-settler apparatus of the reverse liquid flow type having at least one assembly which includes one or more mixers in series, each being fitted with stirrers and pumps, at least one settling tank in which liquids separate, and at least one submerged chute extending into the settling tank from a pump to convey the mixture of liquids from the pumps to the settling tank. The chute is constructed of enlarged dimensions which extend over a major portion of the width of the tank to facilitate a pre-settling action within the chute, and the chute extends a substantial distance into the settling tank to allow extended pre-settling time.
A method and apparatus for mixing two different phases in a liquid-liquid extraction process and for separating the phases employs a spiral stirrer having two tubular coils for creating homogeneous circulation throughout a mixer. The stirrer rotates at a relatively slow speed to create an upward flow from bottom to top of the mixer near the mixer periphery and a downward flow in the middle of the mixer. The mixer has a flow reversing profile ring and is designed to prevent aeration and formation of an emulsion.
This invention provides a process for purifying a cyclosporin, e.g. cyclosporin A, or a macrolide, to a high degree of purity on a large scale. In another aspect this invention provides a bulk quantity of cyclosporin A with an impurity level of less than about 0.7%, e.g. about 0.5%, and compositions thereof.
This invention provides a process for purifying a cyclosporin, e.g. cyclosporin A, or a macrolide, to a high degree of purity on a large scale. In another aspect this invention provides a bulk quantity of cyclosporin A with an impurity level of less than about 0.7%, e.g. about 0.5%, and compositions thereof.
