Absorption is a mainly depends on drug development and medicinal chemistry, the drug should absorbed before any therapeutic effects takes place. Therapeutic effects of drugs is mainly depend on absorption, if the drug is absorbed fast the therapeutic affect will be soon, if it is slow the therapeutic affect will takes times. Furthermore, the drug's pharmacokinetic properties can be easily and sufficiently changed by adjusting factors that affecting the drug absorption
Absorption means the amount of drug absorbed into the bloodstream. The drug is first introduced on the body via some route of administration like Oral, Injection etc. and in a specific dosage form such as a tablet, capsule, solution. Absorption is even more direct and there is less variability in absorption. intravascular administration does not include absorption, and there is no loss of drug. Inhalation is the fastest route of absorption.
Factors Affecting: Dissolution: Absorption is mainly depend on the rate of dissolution and the duration of a Drug's effect can be control by altering the dissolution rate. Several dosage forms are available that contain the same active ingredient but differed only in the rate of dissolution. If a drug is administered in a form that is not readily dissolved, the drug may be released more steadily over time with a longer duration of action. The rate of dissolution is described by the NoyesWhitney equation.
Ionization: absorption is also depend on Ionization. The gastrointestinal tract is made up of epithelial cells. Drugs is permeated through these cells in order to be absorbed into the circulatory system. One particular cellular barrier that may prevent absorption of a given drug is the cell membrane. Cell membranes are mostly lipid bilayers which form a semipermeable membrane. lipid bilayers are normally permeable only to small, uncharged solutes.
Last date updated on July, 2014