Immediate and Modified release tablets and requirements of an ideal tablet formulation
These types are classified according to the release of the drug, either Immediate or Modified, where Modified has been divided into two types, Extended and Delayed.
1- Immediate release tablets
It is also called the traditional name, and it is the most common and used type, as this type is characterized by the rapid release of the drug after taking the drug orally, dissolving the tablets, or administering the drug as a solution. Examples of tablets used on this type: effervescent, orally disintegrating, chewable, sublingual and buccal tablets.
2- Modified release tablets
A) sustained release tablets ( Extended ): Continuous-release tablets where the drug is released from the matrix for an extended period of time at an approximately constant rate have first-order pharmacokinetics.
B) Delayed release tablets: The drug is released after a certain period of taking the drug, but when the drug is released, it is rapid and not extended like the first type. An example of this type: It is used in the case of local treatment of the lower part of the colon or intestine, so that in this case we need to delay the release of the drug from tablets such as enteric coated tablet.
C) Oral disintegrating tablet: Such tablets can dissolve in the mouth within seconds without the need for liquid and are used in patients who have difficulty swallowing, such as the elderly and children, and may be used in patients who need faster dissolution of the drug.
Requirements of an ideal tablet formulation:
1- It should be of an appropriate size for ease of administration and swallowing.
2- Free from defects such as cracks, discoloration and contamination.
3- Its content of active ingredients must be maintained during storage.
4- Tablets must be elegant in shape.
5- The tablets must be strong and tough enough to withstand maneuvering.
6- The drug in the tablets must be biologically available, which can be confirmed by a disintegration, dissolution and bioavailability study.
7- The content of the tablets must be of a uniform weight, and this can be done through quality control to ensure that all the contents of the tablets are uniform in all units.