Steps Involved in Tablet Compression
Tablet compression is a crucial step in the manufacturing process of solid oral dosage forms. It involves transforming a blend of active pharmaceutical ingredient (API) and excipients into a compact tablet form using a tablet press. Here are the key steps involved in tablet compression:
1. Pre-Compression Stage
- Material Preparation: The API and excipients, including binders, fillers, disintegrants, and lubricants, are accurately weighed and mixed to form a homogenous powder blend.
- Granulation (Optional): In some cases, dry or wet granulation may be employed to improve powder flow and compressibility. Granulation involves agglomerating the powder mixture into granules, which are
2. Tablet Press Setup
- Tooling Selection: The appropriate tooling (punches and dies) is selected based on the tablet design and size.
- Machine Calibration: The tablet press is calibrated to ensure the correct compression force, tablet thickness, and weight.
3. Filling the Die Cavity
- Feeding the Powder Blend: The powder blend is fed into the tablet press hopper.
- Feeding System: The tablet press has a feeding system that allows controlled delivery of the powder blend into the die cavity.
4. Tablet Compression
- Upper Punch and Lower Punch: The tablet press has two punches, the upper punch, and the lower punch. The upper punch descends into the die cavity and compresses the powder blend.
- Compression Force: The upper punch applies a specific compression force to the powder blend, compacting it into a tablet.
- Die Filling: The powder blend fills the die cavity, and excess powder is scraped off to ensure a uniform fill.
- Compression Depth and Speed: The depth and speed of compression are controlled to ensure the tablets are of the desired hardness and quality.
- Ejection: After compression, the lower punch is lifted, and the tablet is ejected from the die cavity by an ejection mechanism.
5. Tablet Quality Control
- In-Process Checks: Tablets are regularly inspected during compression to detect defects, such as capping or sticking, and ensure tablet uniformity.
- Weight Variation: Tablets are periodically sampled and weighed to check for weight variation and ensure content uniformity.
- Hardness Testing: Tablet hardness is measured to ensure tablets meet the desired mechanical strength.
- Thickness and Diameter: Tablets are measured for their thickness and diameter to ensure consistency.
6. Packaging
After successful compression and quality control checks, the tablets are collected and prepared for packaging. The tablets are often coated or packaged in appropriate containers for distribution and storage.
Conclusion
Tablet compression is a critical step in tablet manufacturing, where the powder blend is compacted into solid tablets using a tablet press. Proper material preparation, tooling selection, and tablet quality control ensure that the tablets meet the desired specifications and deliver the correct dose of the active pharmaceutical ingredient to patients.