Method of monitoring a freeze drying process
AssigneeAstraZeneca AB
InventorMikael Johan Alvin Brulls
Life of this patent
Estimating the term…
Abstract
A method of monitoring a freeze-drying process in an apparatus (1) holding one or more samples (9) of a material to be freeze dried, comprises the steps of directing input radiation onto the sample (9), the input radiation forming output radiation by interaction with the sample (9); collecting at least part of the output radiation and leading the thus collected radiation to a radiation analyzer (11); and analyzing the collected radiation spectroscopically in the radiation analyzer (11) to obtain a measurement value of one or more freeze-drying parameters of the sample (9), such as the temperature of the sample (9) and/or the content of a solvent in the sample (9) and/or the structure of the sample (9).
Claims29
A method of monitoring a freeze-drying process in an apparatus (1) holding one or more samples (9) of a material to be freeze dried, characterized by the steps of directing input radiation onto the sample (9), said input radiation forming output radiation by interaction with the sample (9);
- collecting at least part of said output radiation and leading the thus collected radiation to a radiation analyzer (11);
- and analyzing the collected radiation spectroscopically in the radiation analyzer (11) to obtain a measurement value of one or more freeze-drying parameters of the sample (9).
A method according to anyone of the previous claims, wherein said measurement value is fed to a control unit (14), and wherein said control unit (14) controls the freeze-drying process on basis, at least partly, of said measurement value.
A method according to anyone of the previous claims, wherein said input radiation comprises near infrared (NIR) radiation, and said collected radiation is analyzed spectroscopically in the near infrared wavelength region.
A method according to anyone of the previous claims, wherein said input radiation and said collected radiation is led through several optical fibers (12) to and from the sample (9), and wherein said radiation analyzer (11) performs a separate analysis of the collected radiation led through each optical fiber (12) to obtain a respective measurement value.
A method according to anyone of the previous claims, wherein said one or more parameters are related to one or more physicochemical properties of the sample (9).
A method according to anyone of the previous claims, wherein one of said freeze-drying parameters comprises a temperature of the sample (9).
A method according to anyone of the previous claims, wherein one of said freeze-drying parameters comprises a content of a solvent, such as water, in the sample (9).
A method according to anyone of the previous claims, wherein one of said freeze-drying parameters corresponds to a structure of the sample (9), such as a macroscopic structure, a degree of crystallinity or polymorphism.
A method according to anyone of the previous claims, wherein the analysis in the radiation analyzer (11) is based on chemometric methods, such as multivariate statistical analysis.
A method according to anyone of the previous claims, wherein the step of analyzing comprises the steps of generating a sample vector of data values, and condensing said data values into said measurement value.
A method according to anyone of the previous claims, wherein the step of performing a measurement on the sample (9) is carried out on a final product in order to determine the quality of the freeze-dried material.
A method of monitoring a freeze-drying process in an apparatus (1) holding at least one sample (9) of a material to be freeze dried, characterized in that near infrared spectroscopy (NIRS) is used to obtain a measurement value of one or more freeze-drying parameters related to one or more physicochemical properties of said at least one sample (9).
Dependencies are inferred from the claim text.