Formulations are often the key to successful pre-clinical as well as clinical drug development. Formulations for oral drug administration must present the active compound to the gastrointestinal tract in a way that promotes a desirable pattern of dissolution and absorption. Intravenous formulations must keep the active in solution during administration and prevent precipitation at the site of administration. Special formulation considerations apply when non-traditional sites of drug administration, such as dermal, nasal, buccal or vaginal administration, are considered. In addition, first-in-animal pharmacokinetic, preclinical safety or efficacy studies frequently require formulation development prior to initiation of the in-life phase of the study.

We offer various surgically ported animal models to help with formulation assessment in addition to the standard rodent, canine and non-human primate models for oral and intravenous dosing. These include rats, dogs and mini-pigs fitted with intestinal cannulas implanted at various sites for dosing solutions or suspensions as well as dogs fitted with duodenal fistulas for dosing solids, semi-solids, capsules and tablets directly into the duodenum. Several of these animal models are available routinely at Absorption Systems and others can be prepared for customers on an as-needed basis.

The dosing vehicle used to administer a compound can have a profound influence on its absorption. Pharmacokinetic and pharmacodynamic studies in animals require that a test compound be administered in a form that promotes the absorption of the compound into the blood stream. The usual routes for compound administration include bolus intravenous dosing, intravenous infusions, subcutaneous dosing, intraperitoneal dosing and oral dosing. Each route has important formulation requirements in order to assure that the administered dose is absorbed and distributed throughout the body.

We apply several in vitro tests to candidate formulations in order to evaluate their potential as animal dosing vehicles. These include room temperature and refrigerator stability, and stability after dilution in various media that mimic the physical properties of biological fluids, such as artificial gastric fluid, phosphate-buffered saline, albumin solution and artificial intestinal fluid. Candidate formulations that show acceptable behavior in these tests are selected for use in animal dosing studies.