Introduction to Tablets in Pharmaceutics
Tablets are the most commonly used solid dosage forms because they are easy to take, safe, affordable, and convenient for patients. A tablet contains a fixed dose of medicine compressed into a small, easy-to-swallow shape. Tablets also allow accurate dosing and good long-term stability, making them the preferred choice in healthcare.
Uncoated Tablets
Uncoated tablets are the simplest type of tablets. They do not contain any outer covering and are made by compressing the drug along with excipients such as binders, fillers, lubricants, and disintegrants.
Advantages of Uncoated Tablets
- Simple and cost-effective to manufacture
- Fast disintegration in the stomach
- Easy for large-scale production
Disadvantages of Uncoated Tablets
- Poor taste and smell cannot be masked
- Not suitable for drugs sensitive to stomach acid
- Less protection from moisture and heat
Coated Tablets
Coated tablets are covered with an additional layer (film, sugar, or polymer) to improve appearance, taste, stability, and swallowing experience. Coating also protects the drug from light, moisture, and acidic conditions in the stomach.
Types of Tablet Coating
1. Sugar-Coated Tablets
These tablets are coated with a thick sugar layer. It masks bitter taste and gives a shiny, attractive look. Mostly used for pediatric patients.
2. Film-Coated Tablets
A thin polymer film is applied to improve strength, appearance, and taste masking. These tablets are lighter than sugar-coated tablets.
3. Enteric-Coated Tablets
Enteric coating prevents the tablet from dissolving in the acidic environment of the stomach. It dissolves only in the intestine, ideal for acid-sensitive drugs like omeprazole and aspirin.
4. Gelatin-Coated Tablets
These tablets have a gelatin layer that makes swallowing easier and gives a capsule-like feel. They also prevent tampering and counterfeit.
Modified Tablets
Modified tablets are specially designed to release the drug in a controlled or targeted way. They improve therapeutic effectiveness and patient convenience.
1. Sustained Release (SR) Tablets
Sustained release tablets release the drug slowly over several hours. This helps maintain a steady drug level in the body for a long time.
- Reduced dosing frequency
- Better patient compliance
- Lower chances of side effects
2. Extended Release (ER/XR) Tablets
Extended release tablets release medicine over 12–24 hours. They prevent peaks and drops in drug levels and are usually taken once or twice a day.
3. Fast Dissolving Tablets (FDT/ODT)
Fast dissolving tablets melt quickly in the mouth without needing water. These are best for children, elderly patients, or those who have difficulty swallowing.
4. Multilayered (Bilayer) Tablets
Multilayer or bilayer tablets contain two or more layers of drug. This allows combining:
- Two incompatible drugs in one tablet
- Immediate + sustained release in a single dose
- Better control over drug release
Why Tablets Are Popular
Tablets offer many advantages such as accurate dosing, easy handling, long shelf life, and low manufacturing cost. They can be modified to suit different medical needs, such as taste masking, delayed release, fast action, or long-term release.
