The concentration of the active ingredient is another critical factor to consider. The dosage form of a medication must contain the right amount of active ingredient to achieve the desired effect without causing toxicity. For example, the therapeutic window, which is the range of doses that produces the desired effect without causing significant adverse effects, varies widely among different drugs. Therefore, precise dosing and formulation are vital in pharmaceutical development and clinical practice.
In certain cases, particularly in industrial settings or where water quality criteria are stringent, de-ionization is required to remove dissolved salts and minerals. Ion exchange resins are used in this process, which exchange unwanted ions in the water for more benign ones. This method is essential for producing ultra-pure water needed in various applications, such as pharmaceuticals and electronics.
Within these two broad categories, APIs can also be further classified based on their chemical nature. There are natural APIs, which are derived from plants, animals, or minerals. Examples include morphine from opium poppy and digoxin from foxglove plants. Semi-synthetic APIs, which are chemically modified derivatives of natural substances, also play a crucial role. An example is the antibiotic amoxicillin, a derivative of penicillin that is more effective against a range of bacteria.