Page 43 - Pharmaceutics III_ 02-06-01304_Fall 2025_ Pharm D_Electronic book
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o Water enters tablet through semi-permeable membrane, creating osmotic
pressure that pushes drug out via orifice.
4. Ion exchange:
o Drug bound to ion-exchange resin released by exchange with ions in GIT.
Evaluation of Controlled Release Tablets:
• Hardness and friability (same as conventional tablets).
• Uniformity of weight and content.
• Dissolution profile – tested in different media for 12–24 hours.
• Stability under accelerated conditions.
Tablet Compression Machine:
1. Single Punch (Eccentric) Press:
• Single set of punches and die.
• Suitable for small-scale production or R&D.
• Output: 30–200 tablets/min.
2. Rotary Tablet Press (Multi-station):
• Multiple sets of punches and dies.
• High-speed, large-scale production.
• Output: up to 250,000 tablets/hour.
Parts: hopper, feed frame, upper and lower punches, dies, turret, cam tracks.
Advantages: uniform weight and thickness, efficient production, possibility of multi-layer
tablets.
Compression Cycle in Rotary Tablet Press:
1. Filling: Lower punch is at lowest position; die cavity filled with granules.
2. Metering: Excess granules scraped off.
3. Compression: Upper punch descends to compress powder.
4. Ejection: Lower punch rises to eject tablet.
Compression Problems and Remedies:
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