1. Beyrich TH, Tilbussek P (1981) Untersuchungen zur Lichtdurchlässigkeit eingefärbter Plastflaschen. Pharmazie 36(5):337–341
2. Guideline on the Packaging Information of Medicinal Products for Human Use Authorised by the Union. European commission, Revision 14.4, December 2016
3. Guideline on the Readability of the Label and Package Leaflet of Medicinal Products for Human Use. European Commission, Revision 1, January 2009
4. Annex to the European Commission guideline on ‘Excipients in the labelling and package leaflet of medicinal products for human use’ (SANTE-2017-11668), European Commission, November 2019
5. Good Manufacturing Practice Guidelines (EudraLex Vol.4). http://ec.europa.eu/health/medicinal-products/eudralex/eudralex-volume-4_en. Accessed 18 Jan 2022