Pathway™ TPU Excipients


Whether developing new routes of administration for existing drug products or new chemical entities, Lubrizol's thermoplastic polyurethane (TPU) serves as an ideal excipient due to its combination of mechanical properties and compatibility with a wide range of active pharmaceutical ingredients (APIs). Our pharmaceutical-grade Pathway™ TPU excipients are designed to be a customizable, reliable option for controlled drug delivery, making it a smart choice for both new drug development, life cycle management and drug-device combination products. Unique Pathway™ application advantages include:

  • Increased flexibility in chemical structure compared to other biocompatible, non-bioabsorbable polymers, such as silicone or ethyl vinyl acetate (EVA), making it useful with a wider variety of APIs
  • Ability to deliver zero-order, Fickian-diffusion-driven, or hybrid drug-release profiles
  • Ideal mechanical properties with a variety of durometers, from 72A to 60D
  • Availability in small to large batch sizes, including lab or pilot scale

Additionally, our Pathway™ TPUs have established Drug Master Files (DMFs) and are manufactured under IPEC-PQG good manufacturing practice guidelines, which is commonly FDA-required when working with a pharmaceutical or incorporating one into a medical device. Our most requested TPUs for these purposes include:

  • 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

Lubrizol’s TPUs have a long history of in vivo safety, stability, and biocompatibility and, as a result, have been used for decades in biomedical applications such as implanted cardiac pacemakers and defibrillators. Our TPU has been studied for the delivery of a variety of APIs in multiple diseases states, including HIV (1-4), mental health (5), pain (opioid) (6), respiratory (7) and hormone regulation (4).  For additional references supporting TPU usage in drug delivery, see our Reference Guide


  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.