Solubility and Diffusion Testing of High Potency APIs in Thermoplastic Polymers

Are you passionate about science, technology, and innovation? At QPharma, we offer exciting thesis opportunities for students who want to apply their academic knowledge to real-world challenges within pharmaceutical development and manufacturing. Whether your interests lie in research, engineering, or process development, our thesis projects offer an opportunity to explore new ideas, gain valuable industry experience, and contribute to the development of future pharmaceutical solutions.QPharma, is a global contract development and manufacturing organization (CDMO) for pharmaceutical products. With a strong focus on innovation and continuous development, we are always looking for new perspectives and ideas to help shape the future of pharmaceutical development.BackgroundThermoplastic polymers such as ethylene-vinyl acetate (EVA), polyurethanes, and other medical-grade materials serve as the basis for many long-acting drug-delivery systems. These polymers are selected for their biocompatibility, ability to be processed by extrusion or molding, and capacity to embed active pharmaceutical ingredients (APIs) for controlled release over extended periods. For high-potency APIs, ensuring predictable and stable release profiles is critical due to narrow therapeutic windows and safety concerns.A central challenge is understanding API solubility and diffusion within the polymer matrix. Solubility sets the limit of API that can reside in the amorphous polymer regions, while diffusion dictates how rapidly the dissolved drug migrates through the network—together defining permeability and shaping release kinetics. EVA, for instance, is produced in various grades differing in vinyl acetate content, enabling adjustment of crystallinity, flexibility, and drug-polymer compatibility. However, predicting solubility and diffusion is complex, since both depend on polymer chemistry, processing, morphology, and API properties.This thesis investigates and optimizes methods for measuring solubility and diffusion of high-potency APIs in selected thermoplastic polymers, aiming to establish reliable approaches that advance polymer-based controlled-release system development.ObjectivesLiterature ReviewMethod Evaluation and Optimization· Compare advantages and limitations of common approaches.· Identify sources of variability when different sample‑preparation techniques (e.g., extruded vs. compression‑molded films) are used.· Propose improvements to enhance reproducibility and applicability to high‑potency APIs.Impact of Polymer Processing Conditions and Macromolecular Characteristics· Study how parameters such as cooling rate, melt temperature, orientation, and crystallinity affect polymer permeability.· Establish the relationship between polymer morphology and transport properties.· Macromolecular characteristic, such VA content.Experimental Assessment· Prepare polymer films via selected processing routes.· Testing and developing a new method under development.· Measure solubility and diffusion values of a reference API and other new candidate APIs in different grades of EVAs.· Compare findings across different polymer grades and processing conditions.Data Integration and Interpretation· Use solubility and diffusion data to discuss implications for controlled drug‑release design.· Provide recommendations for method selection and polymer choice in future development work.Expected OutcomeThe project is expected to deliver:A concise evaluation of solubility and diffusion methods suitable for HPAPI–polymer systems.Practical recommendations for standardized SPS workflows (sample preparation, measurement technique selection).Enhanced understanding of how processing history affects permeability, improving the reliability of future development work on rings, implants, and similar drug‑delivery devices.Contact PersonAnders Wall, Principal Analytical [email protected](+46) 040 36 18 30