Designing a pharmaceutically acceptable drug delivery system: importance of defining the target product profile (TPP)

Designing a pharmaceutically acceptable drug delivery system requires a strategic, science-driven approach that balances innovation with regulatory expectations. A central element in this process is the development of a well-defined Target Product Profile (TPP). The TPP serves as a prospective roadmap, articulating the intended clinical use, route of administration, dosage form, dosing regimen, and key quality attributes of the final product. By establishing these criteria early, the TPP guides formulation scientists and development teams in making rational decisions about excipient selection, delivery technologies, manufacturing methods, and analytical strategies. It also facilitates alignment across stakeholders, including R&D, clinical, regulatory, and commercial groups, thereby reducing risks of late-stage failures. Importantly, the TPP anchors quality-by-design (QbD) principles by linking desired clinical performance to critical quality attributes and process parameters. This structured framework enables efficient optimization of stability, bioavailability, and patient compliance while ensuring regulatory compliance and cost-effectiveness. In an increasingly complex therapeutic landscape—spanning biologics, nucleic acid therapies, and novel delivery platforms—the TPP is indispensable for translating molecular innovation into a viable, pharmaceutically acceptable drug product. Ultimately, defining the TPP is not a static exercise but an evolving blueprint that ensures successful product development and long-term therapeutic impact. This will be illustrated with some case studies.

Dr. Rajiv Nayar is the Founder and President of HTD Biosystems, a leading Contract Research Organization (CRO) specializing in drug product development for protein and vaccine formulations, lyophilization processes, and advanced drug delivery systems. HTD Biosystems partners with emerging biotechnology companies worldwide to accelerate innovation and product development. Prior to founding HTD Biosystems, Dr. Nayar held senior leadership roles at Bayer, where he established and directed the Formulation and Drug Delivery Group within the biotechnology division. He led global efforts in developing protein- and peptide-based therapeutics across Bayer’s international network, earning three consecutive Presidential Achievement Awards for implementing continuous improvement practices in pharmaceutical development. Dr. Nayar is an inventor on 28 patents and has authored more than 70 scientific publications. He is also the lead inventor of Bayer’s albumin-free Factor VIII formulation, commercialized as Kogenate® FS. Earlier in his career, Dr. Nayar was part of the Canadian Liposome Company, where he contributed to the development of liposomal anticancer therapeutics, including doxorubicin (Myocet®) and vincristine (Marqibo®). Dr. Nayar earned his Ph.D. in Biochemistry from the University of British Columbia and completed an MRC Fellowship at the M.D. Anderson Tumor Institute.