These tablets are formed by the process of pressing powdered, crystalline or granular materials, alone or in combination with excipients to form a compact adherent mass of predetermined shape.
The tablet is a vehicle for conveying the medication to the patient and therefore, the formulator should be aware of the limitations of the raw materials and equipment since these affect the bioavailability of the medicament.
Basic parts of Tableting Machines
This is consist of a hopper, feed shoe, weight adjustment, collar (which when turned clockwise, reduces the fill weight and when turned counter clockwise increases the fill weight), one set of the cavity and punches (upper and lower), discharge chute, cam and an upper adjustment collar (which determines the position of the lower punch at the point of ejection of the finished tablet)
For increase production output, these machines offer great advantages. A head carrying a number of sets of dies and punches revolves continuously, while the tablet granulation runs from the hopper, through a feed frame and into the dies placed in a large steel plate revolving around it.
The rotary tablet machines have been developed into models capable of producing multiple-layered tablets. These machines are able to make one, two or three layered tablets.
— Also called Pre-compression; Double Compression Method
— This method is applicable to tablet ingredients that are/ have sensitive to moisture
Raw material arrow_forward weighing arrow_forward Screening arrow_forward Mixing arrow_forward Slugging arrow_forward Milling arrow_forward Screening arrow_forward Mixing arrow_forward Compression
A. Direct Compression
Raw material arrow_forward Weighing arrow_forward Screening arrow_forward Mixing arrow_forward Compression
B. Granulation by Compression
This method is adopted for tablets components that are sensitive to heat, moisture or both. It is further divided into two methods namely
A. Wet Granulation
Raw material arrow_forward Weighing arrow_forward Screening arrow_forward Wet massing arrow_forward Sieving/Milling arrow_forward Drying arrow_forward Screening arrow_forward Mixing arrow_forward Compression
Additives or Excipients furnish bulk or volume to the tablets and are classified according to their functions as follows:
These are substances that make up the major portion of the tablet, usually:
1.a. Lactose USP
Most often used because of the following advantages:
1.e. Microcrystalline Cellulose (Avicel)
1.f. Hydrolyzed starch with dextrose
Other common diluents
These Excipients are substances that “glue” powders together, and cause them to form granules. Binders are added in dry form to the powdered medicaments and activated by the addition of water or other solvents to form a slurry or paste.
Examples of raw materials employed as binders are:
These are substances or agents added to compressed tablets to cause them to “break apart” or disintegrate, when placed in an aqueous medium.
Examples of raw materials employed as disintegrants are:
Super disintegrants: Swells up to ten fold within 30 seconds when contact water.
These are substances which:
Examples of raw materials employed as lubricants are:
Coloring agents are added to tablet granulations for the following purposes:
These are substances added to tablet formulations mainly to “mask” the undesirable flavor of certain medicaments.
Examples of raw materials employed as flavoring agents:
These are substances capable of holding quantities of fluids or moisture in an apparently dry state.
Examples of raw materials employed as adsorbents:
Sugar coating machines are used for average coating and polishing of formed tablets and pills in pharmaceutical and food industry.
— traditional method; process is prone to coating faults eg, poor and uneven coverage, and variation in color from batch to batch
— Easier to use and permit comparatively fast color coating
Traditional panning equipment, capable of achieving impressive results in skilled hands but this technique is not easy to control in terms of modern GMP requirements
These control devices allow programmed variation in dose volume, rolling time, and drying time
specifications and any appropriate compendial requirements
The machine adopt advanced design concept, has compact structure, meet cGMP standard completely.
Modern techniques rely on water as a solvent because of the significant drawbacks that readily became apparent due to the use of organic solvents.