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22 Pharmaceutical Technology ® Trends in Formulation 2022 eBook PharmTech.com Formul ation and drug delivery within the body—outlines four primary processes that are often summarized by the abbreviation ADME. These pharmacokinetic properties can strongly affect the therapeutic efficacy of a drug: • Absorption: Orally administered drugs must enter the bloodstream through the mucus sur- faces of the digestive tract before they can be taken up by the target cells. Many factors such as solubility, chemical stability, gastric empty- ing time, intestinal transit time, and the ability to permeate the intestinal wall can reduce the extent to which a drug is absorbed. • D i s t r i but ion: T he d r u g 's jou r ne y t h r ou g h the bloodstream to various tissues of the body ca n be i n f luenced by blood f low, l ipoph i l ic- ity, molecular size, and the interactions of the d r u g w i t h c o m p o n e n t s o f t h e b l o o d a n d anatomical barriers. • Metabolism: Metabolism is t he process t hat breaks down the dr ug. Most small-molecule FIGURE 2. Biopharmaceutics Classification System (BCS) for new chemical entities. TABLE I. Summary of TPGS's safety characteristics. Country/Region Safety status United States Vitamin E TPGS has a self-affirmed GRAS (generally recognized as safe) status when used as an oral dietary vitamin E supplement. The United States Pharmacopeia (USP) published a monograph for vitamin E TPGS and is included in its current edition USP monographs (2016)*. FDA, as well as the Center for Drug Evaluation and Research (2020) includes tocophersolan (vitamin E TPGS's unique ingredient identifier) on the list of inactive ingredients as in the USP/FDA Substance Registration System. Canada Vitamin E TPGS is listed as tocophersolan by Health Canada in its Natural Health Products Ingredients Database with two roles (2020). The first is a Medicinal role, in which TPGS is classified as a Natural Health Product under Schedule 1, item 3 (a vitamin) of the Natural Health Products Regulations, and the second is a non-medicinal role in which it is classified as an antioxidant. European Community Vitamin E TPGS is approved as an API, a status granted by the European Medicines Agency (EMA) on July 24, 2009. This authorized vitamin E TPGS for the treatment of vitamin E deficiency in pediatric patients suffering from congenital chronic cholestasis or hereditary chronic cholestasis EMA (2020). The European Food Safety Authority, approved its use in foods for special medical purposes on April 17, 2007. Japan Vitamin E TPGS was approved as a pharmaceutical excipient for oral drugs in 2005. Other Countries Several products including pharmaceuticals, medical foods, and dietary supplements are approved on a product and application basis. * The United States Pharmacopeia (USP) published a monograph for TPGS in the_USP/NF Supplement #9 dated November 15, 1998.