Jordan University of Science and Technology

Faculty of Pharmacy

Department of Pharmaceutical Technology

Pharmacy Practice Lab III

Preparation of tablets

 

Objectives:

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)

 

Introduction:

 

Tablets are the common dosage form available in the market due to its desirable advantages which include the following:

 

n      Patient acceptability:

n      Noninvasive

n      Portability

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.

 

 

Tablet manufacturing:

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      Binders

n      Disintegrants

n      Lubricants, and glidants

n      Preservatives

n      Flavoring agents

n      Film formers

n      Opacifiers and colors

 

Identification markings:

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:

-         Drugs.com

-         Rxlist.com

 

 

 

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

 

 

 

 

 

 

 Method:

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.

 

Practical:

  1. Prepare the powder mixture for direct compression.
  2. Watch a demonstration on the operation of the tabeltting machine to produce aspirin tablet by direct compression.
  3. Turn in the in-lab assignment (identification markings & JFDA)