Faculty of Pharmacy
Department of Pharmaceutical Technology
Pharmacy Practice Lab III
1. To prepare tablets by direct compression a powder formulation.
2. To practice using reliable sources of information to find out products from the identification markings on the tablets.
3. To practice using JFDA website (In-lab assignment)
Tablets are the common dosage form available in the market due to its desirable advantages which include the following:
n Patient acceptability:
n Hard to tamper with tablets
n Easy to swallow, especially if coated.
n Relatively easy to manufacture and package
n Provide accurate dosing
n Increased stability of the drug when compared to liquid dosage forms.
n Product identification is easy especially with use of imprints.
n Can be enteric coated or designed for delayed release.
However tablets have few disadvantages which include the following:
n Formulation difficulties, if drug resist compression.
n Some drugs have poor wetting or poor water solubility or poor dissolution which might affect the drug’s bioavailability.
n Bitter taste of the drug might require coating.
n There are 3 main methods of producing tablets:
n Direct compression
n The drug itself is compressible and/or it can be mixed with a filler that is compressible (e.g. lactose).
n Wet granulation
n The powder mixture of the drug and excipients is granulated by wet methods prior to compression.
n Dry granulation
n The powder mixture of the drug and excipients is granulated by dry methods prior to compression.
n In all of these methods the active ingredient is usually mixed with other inactive ingredients (excipients).
n Excipients improve the physical properties of the tablet.
n Excipients are components of tablets that that have a role other than the therapeutic effect, they include:
n Fillers (diluents)
n Lubricants, and glidants
n Flavoring agents
n Film formers
n Opacifiers and colors
In addition to color, size, and shape products can be identified from their tablets using a unique marking. These markings can be embossed engraved or printed on the tablet surface. The following websites can be used to identify a product from the markings on the tablet:
- Lexi-comp online:
Tablet preparation by direct methods:
Tablet ingredients are weighed according to formulation need, blended then compressed. This process is suitable for moisture and heat sensitive drugs.
Direct compression of aspirin tablets:
Ingredients quantity per tablet (mg) quantity for 100 tab (gm)
Aspirin 425 42.5
Aerosil 14 1.4
Dry starch 56 5.6
Magnesium stearate 2.5 0.25
Talc 7.5 0.75
1. Screen each powder ingredient in the mixture to remove any lumps or aggregates.
2. Weigh the proper amount of each ingredient to prepare a total of 100 tablets.
3- Blend the pre-weighed powder to make a homogenous powder mixture.
4- Compress the powder mixture using the single punch press machine available in the lab.