Aim: Preparation and Evaluation of Paracetamol Tablets
References
1. Aulton, M.E., & Taylor, K. (2017). Aulton’s Pharmaceutics: The Design and Manufacture of Medicines. Elsevier Health Sciences.
2. Indian Pharmacopoeia Commission (2022). Indian Pharmacopoeia.
3. Lachman, L., Lieberman, H.A., & Kanig, J.L. (2009). The Theory and Practice of Industrial Pharmacy. CBS Publishers.
Objective
To prepare Paracetamol tablets using the wet granulation method and evaluate the tablets for various quality parameters like hardness, friability, weight variation, disintegration time, and dissolution profile.
Materials Required
Active Pharmaceutical Ingredient (API): Paracetamol
Excipients: Lactose (Diluent), Microcrystalline Cellulose (Binder), Starch Paste (Disintegrant), Magnesium Stearate (Lubricant), Talc (Glidant)
Solvents: Purified Water
Equipment Required: Mortar and pestle, Tablet compression machine, Hardness tester, Friabilator, Disintegration test apparatus, Dissolution test apparatus, Analytical balance, Sieves, Oven
Quantities of Ingredients (for 100 Tablets)
Paracetamol: 500 mg per tablet x 100 = 50 g
Lactose: 150 mg per tablet x 100 = 15 g
Microcrystalline Cellulose: 30 mg per tablet x 100 = 3 g
Starch (for Paste): 10 mg per tablet x 100 = 1 g
Magnesium Stearate: 5 mg per tablet x 100 = 0.5 g
Talc: 5 mg per tablet x 100 = 0.5 g
Purified Water: q.s. (quantum satis) to form a paste for granulation
Procedure
1. Weighing of Ingredients: Weigh 50 g of Paracetamol, 15 g of lactose, 3 g of microcrystalline cellulose, 1 g of starch, 0.5 g of magnesium stearate, and 0.5 g of talc using an analytical balance.
2. Granulation:
- Mix Paracetamol, lactose, and microcrystalline cellulose uniformly in a mortar.
- Prepare a starch paste by dispersing 1 g of starch in a small amount of purified water and heating it until it forms a smooth paste.
- Add the starch paste gradually to the powder mixture while stirring to form a cohesive wet mass.
- Pass the wet mass through a sieve (No. 10 or 12) to obtain granules.
- Dry the granules in an oven at 60-70°C until a constant weight is achieved.
3. Mixing:
- After drying, pass the granules through a sieve (No. 20) to break any large aggregates.
- Mix the granules thoroughly with magnesium stearate and talc to ensure proper lubrication and flow properties.
4. Compression: Compress the granules into tablets using a tablet compression machine. Each tablet should weigh approximately 700 mg (500 mg Paracetamol + 200 mg excipients).
5. Evaluation of Tablets: Perform the following tests to evaluate the quality of the tablets:
a. Weight Variation Test:
- Weigh 20 tablets individually and calculate the average weight.
- Ensure that no more than two tablets deviate by more than 5% from the average weight and none deviates by more than 10%.
b. Hardness Test: Measure the hardness of 10 tablets using a hardness tester. The hardness should be within the range of 4-6 kg/cm².
c. Friability Test:
- Weigh 10 tablets and place them in a friabilator.
- Rotate the friabilator at 25 rpm for 4 minutes.
- Reweigh the tablets and calculate the percentage weight loss.
- The friability should not exceed 1%.
d. Disintegration Test:
- Place six tablets in the disintegration test apparatus.
- Record the time taken for the tablets to disintegrate completely.
- The disintegration time should be less than 15 minutes for uncoated tablets.
e. Dissolution Test:
- Place a tablet in the dissolution apparatus and test using phosphate buffer (pH 5.8) at 37°C.
- Withdraw samples at regular intervals (5, 10, 15, 30, 45, and 60 minutes) and measure the absorbance using a UV spectrophotometer at 243 nm.
- Calculate the percentage of drug release.
Calculations
1. Weight Variation:
Percentage Deviation = 
2. Friability:
Percentage Friability = 
3. Dissolution Profile:
Calculate the percentage drug release at each time point using the standard calibration curve of Paracetamol.
Sample Data Table
| Parameter | Tablet No. 1 | Tablet No. 2 | Tablet No. 3 | Tablet No. 4 | Tablet No. 5 | Tablet No. 6 | Tablet No. 7 | Tablet No. 8 | Tablet No. 9 | Tablet No. 10 | Average |
| Weight (mg) | 700 | 702 | 698 | 701 | 699 | 700 | 703 | 699 | 702 | 700 | 700.3 |
| Hardness (kg/cm²) | 5 | 5.2 | 4.8 | 5.1 | 5 | 4.9 | 5.3 | 4.9 | 5.2 | 5.0 | 5.04 |
| Friability (%) | 0.7 | – | – | – | – | – | – | – | – | – | 0.7 |
| Disintegration Time (min) | 10 | 11 | 9 | 12 | 10 | 10 | 11 | 9 | 10 | 11 | 10.3 |
| Dissolution (%) at 60 min | 92 | 95 | 93 | 94 | 96 | 93 | 95 | 94 | 92 | 93 | 93.7 |
Conclusion
The prepared Paracetamol tablets meet the required quality specifications for weight variation, hardness, friability, disintegration time, and dissolution profile. The tablets are suitable for further studies or for therapeutic use.
