推进口服药品的虚拟生物等价性:方法学,现实应用和未来前景

Pharmaceutical equivalents, by definition, are drug products with the same active ingredient in the same quantities, encapsulated in identical dosage forms, and intended for the same administration routes. These pharmaceutical equivalents are deemed bioequivalent if the bioavailability of the active entity in the drug preparations is similar. Moreover, pharmaceutical equivalents demonstrating bioequivalence are also regarded as therapeutically equivalent. This means that when used as directed,...

Bioavailability refers to the proportion of an unaltered drug that, after administration, enters the systemic circulation and can be distributed to the desired action site. Factors such as gastrointestinal (GI) absorption and liver biotransformation influence the bioavailability of a drug when it is administered orally. When a drug is administered intravenously, it enters the systemic circulation directly; by definition, its bioavailability is assumed to be 100%. The bioavailability of an...

Understanding drugs, drug products, and their performance in pharmaceutical science is pivotal. Drugs, whether simple molecules or complex compounds, are designed to interact with the body's biological systems to diagnose, treat, or prevent diseases. Drug products include various delivery systems such as tablets, capsules, injections, and inhalers. The performance of these drug products is gauged by their ability to deliver the active ingredient to the desired site of action at the...

The selection of a drug's delivery route depends upon its physicochemical properties, including lipid or water solubility and ionization, as well as the therapeutic requirement, such as immediate or sustained effect. These routes can be divided into three primary categories: enteral, parenteral, and topical.
Enteral delivery involves administering drugs directly through swallowing, sublingual placement, or buccal application. Orally administered drugs predominantly navigate the...

The pharmacokinetic journey of oral drugs begins with a crucial first pass through the hepatic portal system, called the first-pass effect. This first pass significantly impacts bioavailability — the proportion of a drug that enters systemic circulation and is available for therapeutic action. The primary route sees the drug absorbed by intestinal membranes and then shunted to the liver via the hepatic portal vein. Here, pre-systemic elimination occurs as drugs face metabolism or biliary...

When a drug is taken orally, it undergoes a journey starting from the gastrointestinal (GI) tract, passing through the portal vein, reaching the liver, and finally entering the systemic circulation. This process involves the absorption of the drug across the GI tract. The liver is the primary site for metabolizing the drug, with some metabolism also occurring in the gut wall. This journey significantly reduces the quantity of the drug that reaches the systemic circulation, a phenomenon known as...