Method for making multiparticulates from a liquid feed employing a spinning disc sprayer
A process for making multiparticulates, comprising providing a molten feed comprising an active ingredient and an excipient, and providing a spinning disc sprayer comprising a rotating disc having a feed-receiving surface driven from above by a hollow drive shaft, wherein axes of rotation of the hollow drive shaft and rotatable disc are coaxial and a downward end of the hollow drive shaft is disposed with a distributor for regulating flow of the molten feed into the well, the distributor and the well together configured for providing a substantially radial, uniform outward flow of the molten feed across the feed-receiving surface.
1 . A method of making multiparticulates, comprising:
providing a molten feed comprising an active ingredient and an excipient;
providing a spinning disc sprayer comprising:
a rotatable disc having a feed-receiving surface and an axis of rotation, the feed-receiving surface defining a well centered on the axis of rotation; and
a hollow drive shaft having a longitudinal shaft lumen and an axis of rotation attached to the rotatable disc;
directing the molten feed through the lumen onto the feed-receiving surface, and atomizing the molten feed from the rotatable disc to form solid multiparticulates;
wherein the axes of rotation of the hollow drive shaft and rotatable disc are coaxial, a downward end of the hollow drive shaft is disposed with a distributor for regulating flow of the molten feed into the well, and the distributor and the well are together configured for providing a substantially radial, uniform outward flow of the molten feed across the feed-receiving surface,
wherein the number of rotatable discs is one and the number of feed-receiving surfaces is one, and
wherein the distributor comprises a plurality of apertures disposed around a circumference of the downward end of the hollow drive shaft for an outflow of the molten feed.
2 . The method according to claim 1 , wherein the feed-receiving surface comprises a peripheral flared portion that slopes gradually in a central and downwards direction towards the well, the well extending further downwards towards a well base end, wherein at least a portion of the feed-receiving surface of the well is more steep than at least a portion of the feed-receiving surface of the flared portion.
3 . The method according to claim 2 , wherein the flared portion of the feed-receiving surface is provided with a plurality of radial channels, wherein each channel is a conduit for molten feed, open at an upwards side, and open at both peripheral and central ends and configured to conduct molten feed from the well to a peripheral edge of the flared portion.
4 . The method according to claim 1 , wherein the rotatable disc is disposed on a downward side with a heat generator configured to regulate a temperature of the feed-receiving surface.
5 . The method according to claim 1 , wherein a pillar is disposed between adjacent aperture pairs, the pillar having in transverse cross section a pillar outer edge, two pillar side edges and optionally a pillar inner edge, wherein the side edges of the pillar converge in a direction towards the center of the hollow drive shaft.
6 . The method according to claim 2 , wherein the hollow drive shaft is dismountably attachable at its downward end through an opening in the well base end of the rotatable disc.
7 . The method according to claim 1 , wherein the hollow drive shaft has a flange at its downward end, wherein an upper surface of the flange is configured to receive a lower surface of the rotatable disc.
8 . The method according to claim 7 , wherein a shaft plug engages with a lower surface of the flange and the rotatable disc is secured to the flange by a plurality of fasteners that extend through a plurality of first openings in the shaft plug, a plurality of second openings in the flange, and a plurality of third openings in the rotatable disc.
9 . The method according to claim 1 , wherein the hollow drive shaft is dismountably attachable at an upward end to a releasable mounting.
10 . The method according to claim 1 , wherein the spinning disc sprayer is further provided with a hollow outer support shaft having a longitudinal shaft lumen for receiving the drive shaft.
11 . The spinning disc sprayer to claim 1 , further provided with an optical camera, configured to capture during spraying one or more images of at least a part of the feed-receiving surface, and feed-particles being sprayed from the feed-receiving surface.
12 . The method to claim 1 , wherein the spinning disc sprayer is configured for partial insertion into a process container having a container volume in which particles ejected from the rotatable disc can undergo transformation, wherein the rotatable disc is immersed in the container volume and an upward end of the spinning disc sprayer is outside the container.
13 . The method according to claim 1 , wherein the molten feed comprises at least one active agent and at least one excipient.
14 . The method according to claim 13 , wherein the at least one excipient is an alkyl-containing glycerol.
15 . The method according to claim 13 , wherein the at least one excipient is a mixture containing mono-, di- and triglyceryl behenates, glyceryl tristearate, hydrogenated cottonseed oil, hydrogenated castor oil, stearyl alcohol, stearic acid and palmitic acid 50, carnauba wax, candelilla wax, stearoyl polyoxylglyceride, or polyglycerol esters of fatty acids.
16 . The method according to claim 1 , wherein the molten feed further comprises at least one of a pore former, a swelling agent, a modified release material, and a viscosity modifier.
17 . The method according to claim 1 , wherein the multiparticulates have a particle size range of from 100 μm and up to about 3 mm.