Go to the hospital to see a doctor, the doctor will give different treatment methods according to the situation, take medicine, infusion. Walking into a pharmacy, several shelves display a variety of drugs, and there are several ways to get it. For the choice of drug types, if there is no clear goal, we surrounded by drugs will fall into choice phobia.
In daily life, we can see a wide variety of drugs, there are various flavors of oral solutions, there are colorful pills, capsules, and particles of various particle sizes.
The dosage form of the drug is a different form of administration made of the drug for the diagnosis, treatment or prevention of different diseases. The same drug will also be processed into different dosage forms for clinical use according to different routes of administration and absorption methods.
Uniform drugs with the same dosage rate will show obvious differences in absorption speed, efficacy and intensity due to different dosage forms. Water agents and injections are more effective than oils, suspensions, and solids; in terms of route of administration, inhalation > intramuscular injection> subcutaneous injection> rectal administration > the skin.
The process of drug absorption is divided into two parts, the first part is the process of transporting the drug from the site of administration to the bloodstream. Intravenous drugs enter the bloodstream directly, while other drugs enter the body through their respective routes of administration and are then absorbed into the bloodstream through the biofilm at the site of their arrival.
Inhalation of the drug is the most efficient in absorption and is comparable to intravenous administration. Gases and volatile drugs enter the alveoli directly through the respiratory tract and are absorbed by the surface of the alveoli to produce a systemic effect. Examples include inhaled anesthetics and isoproterenol aerosols for asthma.
Oral administration is the most common, we usually see tablets, capsules, oral solutions, granules, etc. are administered by oral. The maintenance time of traditional oral drugs is relatively short, which can be improved by coating and capsules, and many new dosage forms have emerged in recent years, such as sustained-release formulations and controlled-release formulations. Oral medications pass through the digestive tract to the small intestine, which is the main site of absorption for oral administration. However, the drug is inactivated by metabolism as it passes through the gastrointestinal tract, intestinal mucosa and liver, resulting in a decrease in the amount of the drug, a phenomenon known as first-pass elimination.
Some drugs have obvious elimination at the first level, and other methods of administration need to be selected. The absorption area of the oral cavity is small, but the blood flow is abundant here, so the sublingual administration is quickly absorbed. Another advantage of sublingual administration is that the drug enters the systemic circulation directly through the sublingual vein, and there is no first elimination, for example, the nitroglycerin tablets for the treatment of angina are taken sublingually.
Some sites of administration are magical, such as rectal administration and vaginal administration.
The physical dissolution change before the drug is absorbed is called disintegration, and how do the various dosage forms of drugs disintegrate?
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