Pathway™ TPU Excipients


Whether developing new routes of administration for existing drug products or developing new chemical entities, thermoplastic polyurethane (TPU) serves as an ideal excipient due to its combination of mechanical properties and drug compatibility. Lubrizol pharmaceutical-grade Pathway™ TPU excipients are designed to be a customizable, reliable choice for drug delivery, making it a smart choice for both new drug development and life cycle management.

Polyurethanes have been demonstrated to be biocompatible and stable in vivo and, as a result, have been used for decades in biomedical devices such as implanted cardiac pacemakers and defibrillators. Lubrizol’s quality systems and processes ensure that we achieve the highest possible quality standards. Pathway TPUs are manufactured in compliance with the IPEC-PQG and USP/NF good manufacturing practice guidelines for pharmaceutical excipients, which is critical in ensuring successful production, handling, and disposition.

Pharmaceutical innovation abounds with this TPU, which is being studied in disease states including HIV (1-4), mental health (5), pain (opioid) (6), respiratory (7) and hormone regulation (4). The most popular pharmaceutical-grade polymers requested for implantable drug delivery are:

  • Pathway hydrophobic polymers:  Aliphatic polyether TPU available in a variety of durometer, color, and radio opaque formulations
  • Pathway hydrophilic polymers:  Aliphatic polyether TPU formulated to absorb water from 20% to 1,000% by weight of the dry resin while maintaining many of its mechanical properties

Application Advantages

  • Highly customizable to meet drug delivery requirements
  • Available in small to large batch sizes, including lab or pilot scale
  • High tear strength and resistance
  • Exceptional durability, even when soft
  • Good chemical resistance
  • Abrasion-resistant
  • Superior clarity


  1. Clark MR, Johnson TJ, McCabe RT, et al. A hot-melt extruded intravaginal ring for the sustained delivery of the antiretroviral microbicide UC781. J Pharm Sci. 2012; 101(2):576-587.
  2. Johnson TJ, Clark MR, Albright TH, et al. A 90-day tenofovir reservoir intravaginal ring for mucosal HIV prophylaxis. Antimicrob Agents Chemother. 2012; 56(12):6272-283.
  3. Johnson TJ, Gupta KM, Fabian J, Albright TH, Kiser PF. Segmented polyurethane intravaginal rings for the sustained combined delivery of antiretroviral agents dapivirine and tenofovir. Eur J Pharm Sci. 2010; 39(4):203-212.
  4. Clark MR, Clark JT, Johnson TJ, et al. Development and pharmacokinetics of a 90-day intravaginal ring for the sustained co-delivery of the microbicide tenofovir and contraceptive levonorgestrel. Poster presented at: Annual Meeting of American Association of Pharmaceutical Scientists; November 10-14, 2013; San Antonio, Texas. Poster T2063.
  5. Schwarz A, Thoroughman S, Winstead D, Decker S, Varughese J. Development of a subcutaneous implant using polyurethane as a semi-permeable membrane for the controlled release of risperidone. Poster presented at: Annual Meeting of the Controlled Release Society; July 15-18, 2012; Québec City, Canada. Poster 155.
  6. Schwarz A, Thoroughman S, Winstead D. Polyurethane as a semi-permeable membrane for controlled release. Poster presented at: Annual Meeting of the Controlled Release Society; July 15-18, 2012; Québec City, Canada. Poster 194.
  7. Subhaga CS, Ravi KG, Sunny MC, Jayakrishnan A. Evaluation of an aliphatic polyurethane as a microsphere matrix for sustained theophylline delivery. J Microencapsul. 1995; 12(6):617-625.