1. Describe the clinical trials process of how a drug is approved by the FDA.
The clinical trials process can be divided into four phases. Phase one, the researchers recruit a small group of healthy people (20-100 people) into the trial. This phase focuses on absorption, distribution, metabolism and elimination. The small dose will be administered. At the end of phase one, the safe dosage and the best route to administer drug will be set.
Phase two is similar to phase one. The difference is that in this phase, the researchers recruit a small group of people who has suffered from the disease which the drug is supposed to effect on. At the end of phase two, the effective dosage and its interval will be determined. In phase three, the researchers …show more content…
Drug absorption depends on its solubility, routes and blood flow to the area for absorption. Lipid soluble, non-ionized drugs are absorbed faster than a water soluble.The cell membranes are lipid bilayers; they allow most lipid soluble drugs easily pass into the cell. Most drugs are absorbed by passive absorption, but some drugs need carrier-mediated transport (active transport). Small molecules diffuse more rapidly than large molecules. Distribution happens after the drugs entering the systemic circulation and transport to the target tissues/organs. The factors that affect drug distribution are similar as absorption, which include protein binding, blood flow to the area, and lipid or water soluble. Lipid soluble drugs may only distribute or store into fatty tissues while water soluble drugs stay in high vascular areas and do not distribute well into most tissues/organs Many drugs transferred from the systemic circulation to various tissues or organs follow the diffusion process. Therefore, drugs are likely to distribute more rapidly to tissues/organs that are more richly perfused with blood. (Textbook, p
The clinical trials process can be divided into four phases. Phase one, the researchers recruit a small group of healthy people (20-100 people) into the trial. This phase focuses on absorption, distribution, metabolism and elimination. The small dose will be administered. At the end of phase one, the safe dosage and the best route to administer drug will be set.
Phase two is similar to phase one. The difference is that in this phase, the researchers recruit a small group of people who has suffered from the disease which the drug is supposed to effect on. At the end of phase two, the effective dosage and its interval will be determined. In phase three, the researchers …show more content…
Drug absorption depends on its solubility, routes and blood flow to the area for absorption. Lipid soluble, non-ionized drugs are absorbed faster than a water soluble.The cell membranes are lipid bilayers; they allow most lipid soluble drugs easily pass into the cell. Most drugs are absorbed by passive absorption, but some drugs need carrier-mediated transport (active transport). Small molecules diffuse more rapidly than large molecules. Distribution happens after the drugs entering the systemic circulation and transport to the target tissues/organs. The factors that affect drug distribution are similar as absorption, which include protein binding, blood flow to the area, and lipid or water soluble. Lipid soluble drugs may only distribute or store into fatty tissues while water soluble drugs stay in high vascular areas and do not distribute well into most tissues/organs Many drugs transferred from the systemic circulation to various tissues or organs follow the diffusion process. Therefore, drugs are likely to distribute more rapidly to tissues/organs that are more richly perfused with blood. (Textbook, p