Drug injection can lead to a dependency by both physical and psychological means — and develops more quickly than with other methods of taking drugs. In recreational-use drug culture, preparation may include mixing the powdered drug with water to create an aqueous solution, and then the solution is injected. This act is often colloquially referred to as "slamming", "shooting [up]", “smashing”, "banging", "pinning", or "jacking-up", often depending on the specific drug subculture in which the term is used (i.e. heroin, cocaine, or methamphetamine). There are a variety of reasons why drugs would be more attractive to inject rather than take through other
Center for Drug Evaluation and Research new drugs on healthy volunteers in small groups to determine the maximum safe dosage. Phase II trials involve patients with the condition the drug is intended to treat to test for safety and minimal efficacy in a somewhat larger group of people. Phase III trials involve one to five thousand patients to determine whether the drug is effective in treating the condition it is intended to be used for. After this stage, a new drug application is submitted. If the drug is approved, stage IV trials are conducted after marketing to ensure there are no adverse effects or long term