Tablet manufacturing process
Tablet manufacturing process is a method of confectionery manufacture that shares many similarities with tablet pharmaceutical production. The manufacture of oral solid dosage forms such as tablets is a complex multi-stage process under which the starting materials change their physical characteristics a number of times before the final dosage form is produced.
Tableting methods :
- Direct compression : suitable for drugs that possess good flowability and compressibility, and which can be mixed well and do not require further granulation steps prior to introduction to the tablet press
- Dry granulation : suitable for drugs that are sensitive to moisture and heat
- Wet granulation : suitable for drugs that are stable to moisture and heat.
−Regardless of weather tablets are made by direct compression or granulation, the first step, milling & mixing, is the same; subsequent steps differ.
−Numerous unit processes are involved in making tablets :
- Particle size reduction and Sizing,
- (frequently) Coating
Tablet manufacturing process Flow chart
Dispensing (weighing and measuring)
−Dispensing is the first step in any pharmaceutical manufacturing process.
−Dispensing is also one of the most critical steps in pharmaceutical manufacturing: during this step, the weight of each ingredient in the mixture is determined according to dose.
- weighing accuracy,
- dust control (laminar air flow booths, glove boxes), during manual handling,
- lot control of each ingredient,
- material movement into and out of dispensary should be considered during dispensing.
−The sizing (size reduction, milling, crushing, grinding, pulverization) is an impotent step (unit operation) involved in the tablet manufacturing.
−In manufacturing of compressed tablet, the mixing or blending of several solid ingredients of pharmaceuticals is easier and more uniform if the ingredients are approximately of same size.
Advantages associated with size reduction in tablet manufacturing:
i.It increases surface area, which may enhance an actives dissolution rate and hence bioavailability.
ii.Improved the tablet-to-tablet content uniformity by virtue of the increased number of particles per unit weight.
iii.Improved flow properties of raw materials.
iv.Improved color and/or active ingredient dispersion in tablet excipients.
−Drying is an important step in the formulation and development of pharmaceutical product.
|•Over drying (bone dry)
•Possible fire hazard
|• Fluidized bed dryer,
• Vacuum tray dryer,
• Microwave dryer,
• Spray dryer,
• Freeze dryer,
• Turbo – tray dryer,
• Pan dryer, etc.
|•To keep the residual moisture low enough (preferably as a range) to prevent product deterioration
•Ensure free flowing properties
Stages of Tablet Formation (Compaction Cycle)
1- Die filling
Gravitational flow of the powder from hopper via the die table into the die . (The die is closed at its lower end by the lower punch).
2- Tablet formation
The upper punch descends, enters the die, the powder is compressed until a tablet is formed.
-after maximum applied force is reached, the upper punch leaves the powder i.e. compression phase.
3- Tablet ejection
The lower punch rises until its tip reaches the level of the top of the die.
The tablet is subsequently removed from the die and die table by a pushing device.