Oral Bioavailability Enhancement Technology OBET Platform
Oral intake is the most commonly adopted drug delivery route and almost the only route for TCMs. Absorption of medicinal ingredients into blood after oral intake is subject to many factors, such as chemical properties of the ingredients, solubility and dissolving speed, PH level and other conditions in various parts of the gastric-intestinal tract, bowel movement and emptying speed of the stomach, etc. Many natural medicinal ingredients, such as saponin and flavone families, which together account for 90% of TCM ingredients, have very low efficiency in entering blood after oral intake. It has been found that these ingredients, mostly hydrophilic, are quickly hydrolyzed and structurally modified into liposolubles under the influence of gastric acid and enzymes. Except very few metabolites processed and further converted by bacteria in the digestive tract, the majority of these liposolubles are precipitated in the gastric-intestinal fluid environment and eventually discharged from the body. Take ginsenosides, which are mostly sapoginins, for example. Bioavailability of Rb1, Rh2 and Rg1 are 1%, 3.4% and 1.9% respectively. Shenyi Capsule, a TCM extract product with ginsenoside Rg3 as its main active ingredient, was approved by Chinese SFDA in 2000 even though Rg3 level is too low to be measurable in blood.
An ideal solution to the bioavailability problem of many TCM ingredients is protection of the ingredients in their intact molecular form from effects of gastric-intestinal fluids and increasing stomach absorption as opposed to intestine absorption. Advancing absorption in the upper digestive tract minimizes the ingredients’ contact with digestive fluids and prevents the modification of the ingredients into medicinally inactive substances.
OBET includes a series of organic solvents and conditioning processes to increase the stability of ingredients in the gastric acid environment. Dosage forms designed with OBET ensure ingredients to be absorbed into blood in their intact molecular forms and primarily in the stomach rather than in the intestines. The result is a much higher bioavailability of ingredients in their medicinally active form and greatly enhancement of the pharmacological effects. Key OBET techniques have already been applied for patent.