Medicine tablets same as capsules are considered as more convenient than liquid oral forms. Tablets are easy to carry around without any worries of breaking or spilling. They are easier to take without the unpleasant taste- a common complaint of most patients for syrups and suspensions. And more to this, some tablets can be taken without water.
Tablet dosage forms appear in various colors and shapes. They have many forms too. These types can be based on each tablets use or mode of action.
The following are facts about the different tablet forms:
- Based on use
Antacids and most vitamin tablets are designed as chewable types. These forms are agreeable tasting that no water is necessary for a follow up. While chewable tablets are applicable for antacids for fast relief, these types are also beneficial for people and younger individuals who are incapable in swallowing a regular tablet type.
This form is placed under the tongue for immediate effect. An example is Isordil sublingual 5mg. This drug is normally administered for minor heart palpitation attacks.
Image by the author
Same as sublingual, the use of a buccal tablet is to make a drug work faster. However, instead of placing the tablet under the tongue, a buccal tablet is placed at the side of the cheek or between the lip gums. Like the sublingual type, a buccal tablet also contains active ingredients that should be absorbed through the oral mucosa to avoid being destroyed by the GIT.
Fentanyl (Fentora) tablet for cancer pain is a buccal tablet type.
Implantation tablets are also known as pellets. These types are without excipients or additives (disintegrants, colorants, lubricants etc.) Implantations tablets must be sterile because they are inserted into the body tissues by surgical procedures. An example is testosterone hormone and stilbestrol. Implantation is designed to be more compact thus, has slow solubility into the body tissues. However, these tablets have been replaced by other dosage form such as diffusion controlled silicone tubes filled with drug or biodegradable polymers that contain entrapped drug in assortment of forms.
Vaginal tablets are also referred to as inserts. These are specially formulated and shaped tablets intended to be placed into the vagina for localized effect. Canesten tablet, a drug for vaginal infections is an example of vaginal tablet.
Special oral tablet
Special oral tablets are categorized into two: the multilayered and the coated tablet.
- Multilayered tablet
Ever notice a tablet with different color layers? The cold medicine Neozep tablet has the white and green color layers. Multilayered tablets are intended to separate two or more different inert substances with the colored layers as the distinction these inert components. These colored layers have different weight adjustment meaning they do not dissolve at the same time.
Multilayered types are normally intended when two or more active ingredients are incompatible with one another.
- Coated tablet
Coated tablets are smooth and they can have a sweet taste (sugar coated) ideal for individuals who have difficulty in swallowing. But, like the multilayered types, a coated form is also used as a scheme to separate two incompatible active constituents. More to this, not only that coated forms shields the inert component being destroyed in the gastro intestinal tract as it dissolves completely in the stomach, it also protects the patient from undergoing gastric discomfort.
An example is a film-coated erythromycin stearate. This drug causes stomach upsets at the same time its active component is acid-sensitive. Aspilet aspirin is another one, although it is not acid sensitive. There are two tablet types of Aspilet- the regular and the enteric coated form. While its ordinary type tablet can cause stomach irritation, the enteric coated Aspilet is not likely to cause such discomfort.
- Based on mode of action
Effervescent tablets are those employed to produce carbon dioxide by chemical reaction of the components upon addition of water. Examples of effervescent tablets are Alka-seltzer and acetylcysteine (Fluimucil). These types provide fast relief, good stomach and intestinal tolerance and consistent response than other forms of tablets and capsules.
A soluble tablet is prepared by mixing powders and then moistening the mixture by alcohol solution. It is formed into molds then dried.
Examples are hypodermic tabs and tablet triturates especially used in antibiotics for administration in infant formulas or in other suitable liquids.
Sustained released tablet
Sustained released tablets are intended to provide immediate release of the drug by producing the desired effect but then has also the capacity to gradually release continually the other amounts of drug to maintain the level of effect over an extended period usually from 8 to 12 hours. An example of this is Feosol spansule- anti-anemia drug.
Most drug outlets are non-strict nowadays. In some countries, medications except for the regulated or dangerous ones can be bought without any prescription. And with the free choice of people to buy generic equivalents, there are some inexperienced pharmacy employees who may recommend an unsuitable drug alternative. Drug forms as capsules, tablets and its subtypes play a major role on how a drug works. If you are going to let a pharmacy personnel change your medicine brand, consider the dosage form too. For one thing, switching from an enteric coated to a regular tablet may seem harmless, but now you know.
© Phoenix Montoya @ January 31, 2011
Compiled Notes in Manufacturing Pharmacy by Emma G. Pena MS Pharmacy and Imelda G. Pena Industrial Pharmacy 2010
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