Subcutaneous injections are a type of injection where a medication is administered just beneath the skin, rather than into a muscle or vein. Medication given this way is usually absorbed more slowly than if injected into a vein. This type of injection is used when other methods of administration might be less effective. For example, some medications can’t be given orally because acid and enzymes in the stomach would destroy them. Other methods, like intravenous injection, require a medical professional to administer and therefore, can be costly. For certain drug candidates, a subcutaneous injection can be a useful, safe, and convenient method of getting a medication into your body.
The non-active liquid in a subcutaneous injection is called the "vehicle" or “formulation”. The formulation is the medium that carries the active ingredient (also known as the active pharmaceutical ingredient or API) into the body. The vehicle or formulation can vary in type from a simple solution, a suspension, an in-situ forming gel or even a solid implant.
In subcutaneous injections, the formulation is often an aqueous solution, such as water or saline, that helps to dissolve and stabilize the active ingredient. The formulation will often be made at a specific pH and may also contain other additives or “excipients”, such as preservatives, or surfactants, to enhance the stability and delivery of the active ingredient.
In some cases, the formulation maybe a non-aqueous solution or suspension when the active ingredient is more lipophilic in nature. The choice of vehicle or formulation depends on the properties of the active ingredient and the intended use of the injection.
Pion Inc. has developed a Subcutaneous Injection Site Simulator (SCISSOR) to aid drug developers in screening formulations in order to optimize therapeutic compounds and biomolecules for subcutaneous injection. SCISSOR can reduce the number of animals required for testing and compare different formulations to identify the best candidates for further development. By simulating the subcutaneous space and physiological conditions, the instrument monitors the stability of the drug upon injection, while also collecting release/concentration profiles of the drug for candidate comparison.
Contact us today to learn more about how SCISSOR can help you accelerate your subcutaneous injectable drug formulation and development efforts by helping you screen drug formulation candidates in an in vitro environment.
