Tablets are the most widely used solid dosage form in pharmacy. They are prepared by compressing powdered or granulated materials into a solid unit. Tablets are popular because they are stable, convenient, economical, and easy to transport. They can deliver drugs for immediate, delayed, or controlled release depending on the formulation design.
Advantages of Tablets
- Easy to administer and portable
- Accurate dose in each unit
- Good physical and chemical stability
- Low manufacturing cost
- Mask unpleasant taste with coatings
- Suitable for large-scale production
Disadvantages of Tablets
- Not suitable for children or patients with swallowing difficulty
- Cannot be used for drugs that are unstable in stomach acid
- Some drugs have poor compressibility
- Slow onset for some formulations
Ingredients Used in Tablets (Excipients)
- Diluents: Add bulk (lactose, microcrystalline cellulose)
- Binders: Increase cohesiveness (starch paste, PVP)
- Disintegrants: Help tablet break apart (croscarmellose sodium)
- Lubricants: Reduce friction during compression (magnesium stearate)
- Glidants: Improve powder flow (talc, silica)
- Colorants and flavoring agents
- Coating materials
Manufacturing Methods
1. Wet Granulation
- Mixing of drug and excipients
- Preparing a wet mass using a binder solution
- Granulation and drying
- Compression into tablets
2. Dry Granulation
- Used for moisture-sensitive drugs
- Powder is compacted and then milled into granules
- Compressed into tablets
3. Direct Compression
- Simplest and fastest method
- Drug and excipients are mixed and directly compressed
Types of Tablets
- Immediate-release tablets
- Sustained/Controlled-release tablets
- Chewable tablets
- Effervescent tablets
- Buccal and sublingual tablets
- Enteric-coated tablets
- Film and sugar-coated tablets
- Dispersible tablets
- Vaginal tablets
Tablet Evaluation Tests
1. Appearance and Weight Variation
Ensures uniformity.
2. Hardness Test
Checks the mechanical strength of tablets.
3. Friability Test
Measures tablet resistance to abrasion.
4. Disintegration Test
Time taken for a tablet to break into small particles.
5. Dissolution Test
Determines the rate and extent of drug release.
6. Content Uniformity
Ensures each tablet contains the correct amount of drug.
Coating of Tablets
Tablets may be coated to:
- Improve appearance
- Mask taste or odor
- Control drug release
- Protect drug from moisture or stomach acid
Types of Coatings
- Sugar coating
- Film coating
- Enteric coating
Packaging and Storage
- Stored in moisture-resistant containers
- Protected from light and heat
- Blister packs, strip packs, and bottles commonly used
Patient Counseling Points
- Take tablets with sufficient water unless instructed otherwise
- Do not crush or chew modified-release or enteric-coated tablets
- Store tablets in a dry place
- Report difficulty swallowing tablets to the pharmacist
Detailed Notes:
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