Pathway™ TPU Excipients

LLS Health has been a leading supplier of medical and pharmaceutical grade polymers for more than 50 years. Our Pathway TPU Excipients build upon this expertise, offering controlled drug release and compatibility with a wide range of active pharmaceutical ingredients (APIs). Pathway TPU is an ideal option for implantable drug delivery systems and drug/device combination products. Whether you are developing a 505(b)(2) product or creating a novel drug device combination product for a new chemical entity, Pathway polymers serve as a highly customizable, reliable option for controlled drug delivery. Unique advantages of Pathway polymers include:
  • Versatile chemistry – Increased flexibility in chemical structure compared to other biocompatible, non-bioabsorbable polymers, such as silicone or ethyl vinyl acetate (EVA), offering better control of drug elution and compatibility with a wider variety of APIs
  • Ideal mechanical properties – Choose from a variety of Shore durometers, from 72A to 60D
  • Customizable drug release – Ability to deliver zero-order, Fickian-diffusion-driven, or hybrid drug release profiles
  • Flexible supply – Availability in small to large batch sizes, including lab or pilot scale to support early development and GMP material for clinical trials and commercial production
  • A history of use – Lubrizol’s TPU polymers have been used in FDA-approved implantable systems for decades due to their biocompatibility, chemical resistance, and customizable mechanical properties. 
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 an API 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
LLS Health’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 implantable devices. 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 (6), respiratory (7) and hormone regulation (4). For additional references supporting TPU usage in drug delivery, see references below.


  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.