All medicinal products need to be protected and packaged in containers which conform to prescribed standards. The quality of pharmaceutical packaging can have a significant impact on the performance of pharmaceutical products and can reduce shelf-life if the improper packaging is used. The USP chapter, <671>, “Containers – Performance Testing” provides standards for the functional properties of packaging systems used for solid and liquid oral dosage forms for pharmaceuticals and dietary supplements. This application note demonstrates the determination of spectral transmission of plastic pharmaceutical containers using the PerkinElmer LAMBDA™ 1050+ UV/Vis/NIR spectrophotometer, in accordance with USP <671>.