Human hormones, such as growth hormone (hGH), prolactin (hPRL), placental lactogen (hPL) or growth hormone variant (hGH-V) are homologous protein hormones which are potent endogenous chemical substances asserting specific biological activities on their respective target organs. Proteins are essential to all biological functions, from metabolism, to growth, to reproduction, to immunity. As such, they halve an important potential role as pharmaceutical agents for the treatment of a wide range of human diseases. Human growth hormone (HGH, somatotropin) is produced in the anterior lobe of the pituitary gland of the human system. It is the most abundant hormone produced by the anterior pituitary lobe, accounting for as much as eight to ten percent of the dry weight of the gland. Growth hormone effects an increase in tissue and organ weight, which results from an increase in mitosis, cellular hypertrophy, hyperplasia and cellular water. Growth hormone also stimulates the increased uptake of amino acids into cells, resulting in protein synthesis. Growth hormone is responsible for proper growth and development until adulthood and then regulates nearly every organ in the body. Human growth hormone products have been used for replacement therapy in growth hormone-deficient children. Growth hormone has also been researched as an adjunct in the treatment of several catabolic conditions such as burn injuries, surgery and malabsorption. The positive effects of growth hormone on calcium ion retention and on osteogenesis also may be of use in the treatment of osteoporosis and non-healing fractures.
Pharmaceuical ingredients or drug, in generally, can be administered to a patient systemically or locally. A systemically administered medicinal substance enters into the blood stream, travels throughout the body, and, hopefully, reaches the part of the patient's body in need of treatment at an effective dose before being degraded by metabolism and excreted. The systemic administration of medicinal substances can be achieved by oral application (e.g., syrups, tablets, capsules and pills), needle injection, transdermal delivery, and subdermal delivery. Systemically delivered medicinal substances can be inefficient, when only a small amount of the administered dose reaches its site of therapeutic action. Typically, a drug is taken orally in the form of a syrup, pill, tablet, capsule and the like, passes through the stomach then into the intestines where it passes through the intestine walls into the blood stream. Alternatively, the drug may be injected directly into the blood stream or into soft tissue where it diffuses into the blood stream. Protein-based therapies such as HGH replacement therapy can be more difficult to administer to patients than other pharmaceuticals. Peptide and protein-based therapeutic agents exhibit poor bioavailability after oral administration. This is due to poor absorption of such macromolecules across the mucosal surfaces of the stomach, intestine and colon. Moreover, peptidase enzymes found in abundance in the gastrointestinal (GI) tract destroy many peptide and protein drug before they have an opportunity to be absorbed. Because the efficacy of a protein is related to its conformation, therapeutic formulations cannot be subjected to conditions that contribute to the unfolding, or denaturing, of the protein.
Growth hormone may be administered by intramuscular or subcutaneous injection. Of these methods, subcutaneous injection may be preferred because it facilitates self-administration. However, both of these methods may be less than optimal because of the psychological or physical trauma that may be associated with administration by human growth hormone injection, especially in children. A variety of HGH delivery systems have been devised to improve the oral bioavailability of drugs including, enterically-coated tablets, capsules, and particles, liposomes, micro- and nanoparticles composed of biodegradable polymers such lactide-co-glycolides, microemulsions with surface active agents incorporated, biodegradable hydrogels, and the like. In many instances, the dosage forms incorporate penetration enhancers. Current methods for administering growth hormone are invasive in that synthetic growth hormone must be administered by daily injection. Therefore, if an orally administered HGH products could be introduced that is safe, efficacious, well tolerated, it would provide an attractive treatment alternative to current growth hormone treatment. HGH pills generally offers sustained release capability which refers to continuous or sporadic release of an active ingredient over an extended time after a single administration, whereby the level of active ingredient available to the host patient often is maintained at some constant level over a period of time. The release of human growth hormone active ingredient is controlled over a period at time wherein the level of active ingredient available to the host may be at a variable but predetermined level at a particular instant in time of treatment. |
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