The invention provides injection vehicles suitable for administering particulate suspensions, such as polymer-based formulations, as well as associated pharmaceutical formulations, articles of manufacture, and kits. Other aspects of the invention included methods for producing and administering pharmaceutical formulations. The injection vehicles of the invention are superior to conventional injection vehicles in that they include a pseudoplastic composition that improves injectability, which facilitates delivery of the desired dose. The injection vehicles of the invention also allow the use of smaller-bore needles than are usually necessary to inject polymer-based formulations, reducing the pain associated with injection of such formulations.