The implantation of a material (e.g. pellet) under the skin
Subcutaneous implantation refers to the implantation or insertion of a material in the subcutaneous layer of the skin. The material, referred to as a subcutaneous implant, may be a pellet. It is delivered under the skin, particularly into the subcutaneous tissues through surgery or by injection. The subcutaneous pellet is a small rod or ovoid form and contains drugs (e.g. steroid hormone) in a compressed form. It is intended to deliver a slow release of the hormone over an extended period of time.
This mode of drug administration is used to deliver leuprorelin, estradiol, and testosterone drugs. Leuprorelin is a hormone used for treating hormone-responsive cancers (e.g. prostrate and breast cancers), uterine fibroids, and endometriosis. Estradiol and testosterone are naturally-occurring steroid hormones. However, they are also produced as a pharmaceutical drug for use as a medication in correcting hormonal levels and for treating hormone-sensitive cancers. In particular, estradiol is given to treat low sex hormone levels in women whereas testosterone is used to treat male hypogonadism. Both of them can be administered through subcutaneous implantation and by other routes (e.g. as a skin gel or patch, or orally)