Powder formation by atmospheric spray-freeze drying
OwnerZhaolin Wang, Warren H. Finlayinventors
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Abstract
A method of manufacturing heat-sensitive pharmaceutical powder is disclosed. The original pharmaceutical substances are dissolved in a solution or suspended in a suspension, which is sprayed through an atomizing nozzle and frozen in a cold gas phase or liquid nitrogen atomized directly in the spray-freeze chamber or gas jacket at the same time (for cooling purposes). The particles are freeze-dried at roughly atmospheric pressure in a down-stream fluid flow with exit filter thereby to remove moisture entrapped on or inside the frozen particles. The system has applicability for forming other powders.
Claims14
A method of creating a powder within a chamber, the method comprising the steps of:
- providing a flow of liquid droplets containing a powder forming ingredient to form a flow of liquid droplets;
- treating the liquid droplets with a flow of coolant inside the chamber to freeze the liquid droplets to form frozen particles prior to deposition;
- depositing the frozen particles on a collector;
- and
- after deposition of the frozen particles, drying the deposited frozen particles to form a dry powder.
Apparatus for atmospheric spray freeze drying of an ingredient carrying liquid to form a powder, the apparatus comprising:
- a chamber having an atomizer at one end of the chamber, the atomizer being connected to a source of the ingredient carrier liquid to produce a flow of liquid droplets;
- an injection system for providing a flow of coolant that entrains liquid droplets sprayed by the atomizer;
- a source of coolant for the injection system;
- and
- a collector spaced from the atomizer sufficiently that liquid droplets atomized by the atomizer are frozen by the flow of coolant before contact with the collector.
Dependencies are inferred from the claim text.