INLINE MEASUREMENT OF MOVING CONTAINERS WITH INFRARED (IR)

SPECTROSCOPY

Field of the Disclosure

The present disclosure is related to a system and method of characterizing or inspecting the content of moving containers with infrared (IR) spectroscopy.

In particular, the present invention can be advantageously applied to inspecting the content of moving containers used in the pharmaceutical field, such as glass or plastic containers, blisters, bottles, vials etc. containing pharmaceutical products, to which reference is made specifically in the present technical description albeit implying no limitation of the scope.

Background of the Disclosure

There are known applications for inspecting the content of containers using (IR) spectroscopy, for example pharmaceutical products.

Current applications inspect from the bottom of the container and can only measure in reflectance mode in case the container is closed and can thus measure only solids and powder type products.

Summary of the disclosure

This disclosure enables the inspection of pharmaceutical products in moving containers from the side with infrared (IR) spectroscopy. This is the part of the electromagnetic spectrum ranging from 10 ^{1 1} Hz to 5x10 ^{1 4} Hz. This region is hereafter referred to by "infrared". When the content of a moving container is inspected from the side with a IR spectrometer, the spectrum measured by the spectrometer is not only affected by IR properties of the container content, but also by speed and position of the container relative to the spectrometer optics. This disclosure eliminates the unwanted effects in such way that the resulting spectrum only represents the IR electromagnetic interaction properties of the container content.

Inspecting the content of moving containers from the side according to the invention makes it possible to inspect the container content in both reflectance and transmittance mode, and thus to characterize powders, solids and liquids. This disclosure provides for a method for characterizing or inspecting the content of a moving container, the method comprises a) passing the container through an optical arrangement so that light signals received therefrom are directed to a processor; b) passing the container through a sensor for determining a position of the container so that information received therefrom is directed to the processor; c) acquiring a moving spectrum of the content of the moving container; and d) formulating by means of the processor a static spectrum of the content of the moving container by comparing said moving spectrum with a reference spectrum. Especially the method claimed is advantageously applied to obtain an inline measurement of the moisture content, and/or a measurement of the alien particles contamination (glass, metal parts etc.), and/or of the polymorphs on the pharmaceutical products inside the containers.

This disclosure also provides for a system for characterizing or inspecting the content of a moving container, the system having at least a) a light source; b) an IR spectrometer, c) an optical arrangement, d) a processor, e) a transport system defining a transport direction; f) an encoder; and g) a sensor, the system being characterized in that the optical arrangement is arranged perpendicular to the transport arrangement and is adapted to inspect the content of the moving container from the side.

Brief description of the drawing The above and other feature of the present disclosure will become clearer by describing in detail exemplary embodiment thereof with reference to the attached drawings in which the sole Figure is a schematic illustration of the system for measuring the transmittance mode of a moving container with infrared spectroscopy according to various embodiments of the present disclosure.

Detailed description of the various embodiments

The disclosure provides for a system and method of characterizing or inspecting the content of a moving container with infrared IR spectroscopy from the side. The disclosure makes it possible to acquire IR spectra of the content of a moving container from the side and thus in transmittance mode even when the container is closed.

Especially the method of the present invention is advantageously applied to obtain an inline measurement of the moisture content, and/or a measurement of the alien particles contamination (glass, metal parts etc.), and/or of the polymorphs on the pharmaceutical products inside the containers.

Data processing techniques are used to eliminate the effects of variable path length and light scattering due to container radius and variable container speed from the acquired spectrum. The resulting spectrum is comparable with a static acquired IR spectrum. The disclosure also includes a method to "reference" the IR spectrometer in-between regular measurements without interrupting the container stream.

According to the drawing, the disclosure provides for a measurement configuration to acquire IR spectra that consists of a light source 10, an IR spectrometer 1 1 , an optical arrangement 12, a processor 13, a transport system in the form of conveyor belt 17 which defines a transport direction to move to container 14, an encoder 15 to record the actual position of the container 14 on the conveyor belt 17 and a trigger sensor 16 to detect the position of the container 14 on the conveyor belt 17. The exact configuration of the optical arrangement 12 depends on the measurement mode. When spectra are acquired in transmittance mode the optical arrangement consist of two focusing lenses where the distance between the two lenses is equal to two times the focal distance of the lenses. Focusing lenses make the measurement less sensitive to position variations of the container. When the spectra are acquired in reflectance mode the optical arrangement consists of a focusing lens with its focal point on the interface between container and container content. Depending on the specific properties of the various sub-ranges of the IR spectrum different approaches are used and lenses can be changed by concave mirror-systems.

The process for measuring the pharmaceutical product in the present disclosure proceeds by passing a container 14 positioned on conveyor belt 17, whereby container 14 is sensed by optical arrangement 12. The optical arrangement 12 leads the signal received there from the spectrometer 1 1 and subsequently to processor 13. Separately, as the pharmaceutical product in container 14 passes on conveyor belt 17, container 14 passes through a beam of light from sensor 16 to detect the position of container 14 in conveyor belt 17. Sensor 16 directs signals to processor 13. Encoder 15 measures the position of container 14 on conveyor belt 17. The processor by means of an encoder continuously tracks the actual position of the transport system. When the trigger sensor detects a container, the processor captures the position of the container in the transport system by recording the actual position of the transport system. As soon as the container is in the center of the optics, based on the actual position of the transport system, the spectrometer is triggered to acquire a single IR spectrum. The measurement time of the spectrometer is optimized for the optical properties of the container and the container content in order to get an optimal S/N ratio. After triggering the IR spectrometer, the processor retrieves the acquired spectrum and transforms into a "static" spectrum by eliminating the effects of variable container speed, variable path length and light scattering. The resulting "static" spectrum can then be used for further data analyses with standard spectroscopic data analyses techniques (i.e. multivariate data analyses).

Transforming moving to static spectra makes it possible to calibrate the system with static containers. To transform the acquired spectrum into a "static" spectrum, the processor needs a reference spectrum to compensate the drift of the light source and IR spectrometer over time. A reference spectrum is an IR spectrum of a reference object, which has stable IR properties and thus spectrum in time. Typically the measurement time of the reference object must be identical to the measurement time of the measured container. But additional data processing techniques in the processor make it possible to use different measurement times for acquiring spectra of the container and acquiring the reference spectra as well. This makes it

possible to use one reference object for different container types and products.

When the containers are measured in transmittance mode, this technique makes it also possible to use the air between the focusing lenses as a reference object and thus to execute a reference measurement in-between two containers without interrupting the container stream. In order to provide the corrrect reading of the measured property, the system requires a calibration by presenting specimens with known quantities and properties to the system.

In an embodiment, the present disclosure provides for the measuring of the containers from the side in transmittance. In another embodiment, the present disclosure provides for the transformation of moving spectra into static spectra.

In a further embodiment, the present disclosure provides for the use of different measurement times for reference and "normal" spectra. It will be understood that the embodiment(s) described herein are merely exemplary, and that one skilled in the art may make variations and modifications without departing from the spirit and scope of the disclosure. All such variations and modifications are intended to be included within the scope of the disclosure as described hereinabove. Further, all embodiments disclosed are not necessarily in the alternative, as various embodiments of the disclosure may be combined to provide the desired result.