System and method for measuring freeze dried cake resistance
AssigneeEisai Co., Ltd.
InventorsWilliam J. Lambert, Zeren Wang
Life of this patent
Estimating the term…
Abstract
A cake resistance measuring system and method are used to measure the cake resistance of a freeze dried sample during or after processing, with the results of the measurement being used to improve that processing and/or subsequent freeze drying processes or formulations.
Claims19
A method for determining cake resistance of a product during or after freeze drying including:
- introducing a gas to a sample of one of a large number of products in a freeze drying production run;
- and
- measuring a change in one of flow and pressure of the gas from the product sample to derive cake resistance.
An apparatus for determining cake resistance during or after lyophilization comprising:
- a source of gas;
- a device controlling the flow of gas to obtain one of constant pressure and constant flow;
- a tube for taking a sample from one of a large number of production samples of a product;
- and
- a sensor for measuring a change in the other of flow and pressure of the gas provided to the sample.
A method comprising measuring cake resistance of one of a number of products in a production run undergoing lyophilization and changing the parameters of the lyophilization process to alter the lyophilization process during the production run.
A method for measuring cake resistance in a freeze dried product comprising:
- inserting into a plurality of different freeze dried products a tube inserted to a different depth for each of the products;
- introducing one of a controlled flow or pressure of gas into each of the tubes;
- measuring the other of pressure and flow of the introduced gas;
- and
- using the multiple tubes at different locations within the products to monitor the cake resistance at different positions within the product.
Dependencies are inferred from the claim text.