A Comprehensive Overview of Tablet Dosage Forms and Their Classification in Pharmaceutical Science

Classification of Tablet Dosage Forms

Tablets are among the most widely used dosage forms in the pharmaceutical industry due to their numerous advantages, such as ease of administration, precise dosing, and extended shelf life. The classification of tablet dosage forms is essential for pharmaceutical scientists and healthcare professionals to ensure optimal drug delivery and patient compliance. This article discusses the various classifications of tablet dosage forms based on their characteristics, release profiles, and manufacturing processes.

1. Classification Based on Release Characteristics

Tablets can be classified based on the release characteristics of the drug they contain. This classification includes

- Immediate Release Tablets These tablets are designed to disintegrate and release the active ingredient immediately after ingestion. They are suitable for drugs that require rapid absorption and onset of action. Common examples include pain relievers like acetaminophen and antibiotics.

- Extended Release Tablets Also known as sustained-release or controlled-release tablets, these formulations are designed to release the drug slowly over an extended period. This reduces the frequency of dosing and maintains more consistent drug levels in the bloodstream. An example includes certain formulations of metformin for diabetes management.

- Delayed Release Tablets These tablets release their active ingredient after a specified delay, often designed to pass through the stomach intact before releasing the drug in the intestines. This type is particularly useful for acid-labile drugs or to target specific areas of the gastrointestinal tract.

2. Classification Based on Manufacturing Methods

Tablets can also be classified based on the methods used in their manufacture. The primary processes include

- Single Compression Tablets Made using a single compression process that combines all ingredients, including active pharmaceutical ingredients (APIs), excipients, and binders, into a uniform mix, which is then compressed into tablets.

- Multiple Compressed Tablets These are made by compressing the tablet twice or forming it in multiple layers. This method is typically used for creating tablets with multiple APIs or different release profiles within the same dosage form.

- Coated Tablets Tablets can also be coated with polymers for various purposes, including taste masking, controlled release, and protection from environmental factors. The coating can be enteric to protect the drug from stomach acid or sugar-coated for palatability.

3. Classification Based on Special Characteristics

There are special types of tablets that serve unique purposes

- Effervescent Tablets These tablets contain acids and carbonates that react with water to produce carbon dioxide. They dissolve rapidly, providing a fizzy drink and are typically used for vitamin and mineral supplements.

- Sublingual and Buccal Tablets Designed for rapid absorption through the mucous membranes in the mouth, these tablets are placed either under the tongue (sublingual) or between the gums and cheek (buccal). They provide quick systemic effects and are ideal for medications that need rapid onset, such as nitroglycerin for angina.

- Chewable Tablets These tablets are designed to be chewed before swallowing, making them a convenient option for children or individuals with swallowing difficulties. They often have a sweet taste and are used for various medications, including antacids and vitamins.

Conclusion

The classification of tablet dosage forms is vital for the effective formulation and delivery of medications. By understanding the different types of tablets and their characteristics, pharmaceutical scientists can design products that meet specific therapeutic needs while ensuring patient compliance. As the pharmaceutical industry continues to evolve, advancements in tablet technology will likely lead to the development of even more specialized and effective dosage forms.