Plastics play a major role in daily life, with unprecedented levels of usage. As anthropogenically produced polymers should be optimized with regard to biodegradability and biocompatibility, green chemistry strategies offer promising pathways. In this context, the symposium on sustainable polymers in Tübingen presented a comprehensive overview of recent advances in polymer research, addressing synthesis and degradation pathways along with environmentally benign catalysts. These developments benefit not only industrial efficiency but also resource conservation and environmental protection. Beyond these sustainability-driven concepts, innovative approaches to biocompatible biomaterials for medical applications and advanced polymer systems for therapeutic drug delivery were highlighted. This conference report presents current polymer research, including contributions from the medical, pharmacological, and ecological fields. To foster interdisciplinary exchange on sustainable polymers, the Tübingen Symposium was initiated by the interdisciplinary faculty College of Fellows: Center for Interdisciplinary and Intercultural Studies at Eberhard Karls University Tübingen, Baden-Württemberg, on October 9, 2025, from 8:30 a.m. to 5:30 p.m., at the Ernst von Sieglin Lecture Hall.
BACKGROUND:This study presents the results of an investigation into the interactions between innovative ophthalmic formulations and commercially available low-density polyethylene (LDPE) containers. The newly developed formulations are self-emulsifying oils (SEOs) containing suspended drug particles, designed to form an emulsion immediately upon contact with tear fluid. Physicochemical and mechanical properties of the containers were evaluated. Interactions between 6 different LDPE containers and the SEO matrix (oil "O" and surfactant Tween 20 "T") were investigated, and the impact of the SEO formulations on the mechanical properties of the containers was assessed. OBJECTIVES:The study aimed to identify potential interactions between SEO components and the packaging that may occur during storage under stress conditions, based on changes in morphology, structure, thermal behavior, and mechanical strength. MATERIAL AND METHODS:The SEO carrier was prepared by mixing Miglyol® 812 with Tween® 20 at a concentration of 5% w/w, followed by sterile filtration. The suspensions were compounded aseptically using sterile, micronized sodium cefuroxime (CEF) and vancomycin hydrochloride (VAN) at a concentration of 5% w/w, along with sodium citrate (2% w/w). In accordance with stability testing guidelines, stress stability studies were conducted in a climatic chamber at 40°C/75% relative humidity and 60°C/75% relative humidity. To detect structural and physicochemical changes, advanced analytical techniques were employed, including Fourier-transform infrared (FTIR) and near-infrared (NIR) spectroscopy for the assessment of structural alterations and potential degradation, differential scanning calorimetry (DSC) for thermal analysis, and X-ray diffraction (XRD) for evaluation of material crystallinity. The mechanical strength of packaging material fragments after contact with the formulations was evaluated using a TA.XTplus texture analyzer. RESULTS:The experiments indicated potential migration (e.g., of plasticizers and residual monomers), as well as adsorption or absorption of excipient components. Subtle interactions were observed, accompanied by negligible changes in the mechanical strength of the packaging material. CONCLUSIONS:The study confirmed the necessity of comprehensive compatibility testing between ophthalmic formulations and their packaging materials. A thorough understanding of these interactions is essential to ensure product stability, safety, and quality during storage and use.
BACKGROUND:Natural gums offer environmentally friendly, biodegradable and non-toxic alternatives to synthetic binders in pharmaceutical formulations. Cocoa pod gum (CPG), derived from cocoa pod husk (CPH), presents a sustainable and underexplored source for pharmaceutical application. OBJECTIVES:This study investigates the potential of CPG as a natural binder in metronidazole tablet formulations, evaluating its physicochemical and compressional properties, mechanical strength, drug release behavior, and compatibility with the active pharmaceutical ingredient. MATERIAL AND METHODS:The CPG was extracted from CPH and characterized alongside xanthan gum (XNG), a standard natural binder. Physicochemical analyses included pH, flow properties, viscosity, particle size, crystallinity, and thermal behavior. Compaction behavior was assessed using Heckel and Kawakita equations. Metronidazole tablets were formulated with varying concentrations (10-20% w/w) of both gums and evaluated for hardness, friability, disintegration time, and in vitro drug release. Compatibility was examined using Fourier transform infrared spectroscopy (FTIR). RESULTS:Cocoa pod gum demonstrated better flow properties and swelling capacity, while XNG showed higher viscosity and plastic deformation, yield pressure (Py) and PK values. Tablets formulated with XNG had greater hardness and slower disintegration, resulting in more delayed drug release. Cocoa pod gum-based tablets disintegrated faster and showed rapid drug release, making them more suitable for immediate release formulations. Fourier transform infrared spectroscopy confirmed no drug-excipient incompatibilities. CONCLUSIONS:Cocoa pod gum exhibits promising binder properties comparable to XNG and may serve as a cost-effective, sustainable and biocompatible alternative to conventional excipients in tablet formulations.
BACKGROUND:Ethylene oxide (EO) sterilization is the most used sterilization method for disposable medical devices. Its popularity is based on the fact that it can be executed on industrial scale on full pallets of packed products and the fact that many materials are compatible with this sterilization technique. OBJECTIVES:This article describes an introduction to EO as a sterilization technique and further studies on the compatibility of medical grade plastics with EO sterilization. MATERIAL AND METHODS:Fourteen different healthcare polymer grades have been exposed to EO. This includes frequently used polyethylenes, polypropylenes, polyesters, and polycarbonates. Their mechanical and optical properties before and after exposure with EO were determined. RESULTS:After both the statistical analysis and a comparison with the accuracy of the measurement system, it can be concluded that all tested polymers retained their mechanical properties as measured by tensile and Izod impact testing after 1 sterilization cycle. Optical measurements showed that only 2 of the polymer grades had a minor discoloration, while all other materials had a very limited color change. CONCLUSIONS:It has been shown that all families of plastics typically used in disposable medical products can be sterilized with EO without significant change in properties as determined on standardized test specimen.
Polymeric surfactants play an important role in the research and development of drugs applied topically to the skin and mucous membranes. Their versatile properties include the ability to lower surface tension, thereby favorably contributing to the energetic balance of the emulsification process during the preparation of various dosage forms. In addition, they offer important structural advantages that enhance the stability of the resulting pharmaceutical or cosmetic products through electrostatic repulsion and steric effects. The influence of viscosity and density should also be taken into account when polymeric surfactants are considered as additives, as these are crucial components of various drug formulations. Emulsions used in ointments and creams are among the most relevant dosage forms affected by surface and interfacial tension phenomena. However, other dosage forms also require the use of surfactants, which may belong to the group of polymeric compounds.
