Track: Manufacturing and Analytical Characterization - Chemical - Analytical - Other
Category: Poster Abstract
Infrared Analysis of Pharmaceutical Packaging
Purpose: The identity of polymer materials used in pharmaceutical packaging must be verified in order to ensure that the materials used are fit for purpose. Infrared spectroscopy provides a fast and simple method for identification of polymers as well as ensuring that the materials being used are permitted by USP chapter < 661.1 >. ATR (attenuated total reflectance) sampling may be used to further simplify data collection as well as allowing users to selectively measure materials on the inside and outside of pharmaceutical packaging. Spectral searching allows for fast identification and therefore verification of materials used in packaging. Methods: Spectra of the inside and outside of multiple different blister packages were measured using an infrared spectrometer with an ATR sampling accessory. The spectral collection parameters used for measurement of packaging materials are shown in Table 1.< br>Table 1. Spectral parameters used for measurement of pharmaceutical packaging materials.
4000 – 450 cm-1
Number of Scans
In order to verify the materials, the collected spectra were searched against a library containing spectra of USP-certified reference materials. Results: An example of the infrared spectrum of the outside layer of packaging is shown in Figure 1 with the ‘best hit’ spectrum overlaid. In this circumstance, the measured material was found to be Nylon-6. A more complex scenario involves the presence of plasticizers within the material. This is particularly prominent in PVC which is frequently used in packaging, but usually includes plasticizers to improve physicochemical parameters such as rigidity and permeability to moisture. An example spectrum of the inside layer of blister packaging with the overlaid ‘best hit’ spectrum is shown in Figure 2. In this case, although the ‘best hit’ spectrum is found to be PVC, there is significant variation in the peak height at 1734 cm-1 which is due to the difference in the quantity of dioctyl phthalate (DOP) as plasticizer which is permitted in PVC packaging up to a level of 2% by USP< 661.1 >. The addition of DOP will improve the rigidity of the polymer, giving it more desirable properties for the use in blister packaging. The peak at 1734 cm-1 corresponds to the stretch of the C=O bond in DOP, providing a distinct identifying feature for this particular material. Conclusion: Infrared spectroscopy provides a fast, simple and non-destructive method for analysis of packaging materials allowing for fast identification and verification of polymer materials used in pharmaceutical packaging. In addition, use of an ATR accessory further simplifies sampling as well as allowing for selective sampling of inner or outer layers of packaging.