Citation: Klemenˇ ci´ c, M.; Bolanˇ ca Mirkovi´ c, I.; Bolf, N. The Inﬂuence of the Production Stages of Cardboard Pharmaceutical Packaging on the Circular Economy. Sustainability 2023, 15, 16882. https://doi.org/10.3390/ su152416882 Academic Editor: Grigorios L. Kyriakopoulos Received: 9 November 2023 Revised: 13 December 2023 Accepted: 14 December 2023 Published: 15 December 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). sustainability Article The Inﬂuence of the Production Stages of Cardboard Pharmaceutical Packaging on the Circular Economy Mia Klemenˇ ci´ c 1 , Ivana Bolanˇ ca Mirkovi´ c 2, * and Nenad Bolf 3 1 Naklada Ljevak d.o.o., Ulica Grada Vukovara 271, 10000 Zagreb, Croatia; klemencic.mia@gmail.com 2 Faculty of Graphic Arts, University of Zagreb, 10000 Zagreb, Croatia 3 Faculty of Chemical Engineering and Technology, University of Zagreb, 10000 Zagreb, Croatia; nenad.bolf@ﬁkt.unizg.hr * Correspondence: ivana.bolanca.mirkovic@grf.unizg.hr Abstract: Packaging appearance is important in a competitive market. Designers strive to create products that attract customers and often use laminated packaging, due to the attractive appearance and quality characteristics of the material. The circular economy in the recycling of cardboard packaging helps to reduce waste, saves natural resources and increases the quality of the environment. All of the above contributes to sustainable production, but the quality and properties of the obtained recycled paper materials should not be ignored. Recycling of laminated cardboard packaging often has a negative impact on the quality of recycled paper, due to the formation of sticky particles that can affect the optical properties of recycled paper and the efﬁciency of the recycling process. This article provides insight into the inﬂuence of each stage of production of packaging intended for pharmaceutical products on the properties and characteristics of recycled paper. The standard INGEDE 11 deinking method was used to remove dyes and other impurities from the pulp. The obtained optical results of the characteristics of recycled laboratory sheets obtained from laminated and non-laminated cardboard samples were compared in order to determine the impact of each stage of box production on the quality of the paper pulp. The acquired knowledge can be applied in the design phase of a more sustainable product, and laminated materials can be used in luxury products or to increase the functionality of the packaging. Designing for recycling will contribute to an increase in the quality of the obtained paper mass, which is directly related to an increase in the productivity of recycling and the sustainability of the packaging production process. Keywords: circular economy; phases packaging production; recycling; optical characteristics 1. Introduction The circular economy is based on the economic advantages created by reducing the impact on the environment and reducing resources. Such an approach can be achieved by passing circularity through the 9R Framework’ extended classic 3R concept [1]. The 9R Framework’ includes recover energy, recycle, reuse, remanufacture, restore, repair, reuse, reduce, rethink and discard. The premise of discarding in a circular economy should be kept to a minimum, but one must not forget to mention the existence of that phase. To reduce the negative impact of the rejection phase, it is possible to combine this phase with the energy recovery phase [2]. The mentioned phase does not contribute primarily to the circular economy (due to the impossibility of uninterrupted energy consumption without major losses), so waste could become a raw material for obtaining energy. The methodology “Circular Economy Product Strategy and Business Model Framework” suggests design and business model strategies to be implemented together [3]. The ReSOLVE framework (regenerate, share, optimize, loop, virtualize, exchange) is a basis for some of the best frameworks as backcasting and eco-design for a circular economy (BECE) [4]. Retrospective planning methodology is useful for complex problems in which current trends are incorpo- rated. Such a planning method can increase the probability of solving ecologically complex Sustainability 2023, 15, 16882. https://doi.org/10.3390/su152416882 https://www.mdpi.com/journal/sustainability