Topical administration

The topical application of medicines has obvious advantages in the management of localised disease. The drug can be made available almost directly at the intended site of action, and because the systemic circulation is not reached in great concentration, the risk of systemic side-effects is reduced. For example:

The use of eye drops containing beta blockers in the treatment of glaucoma;

The application of topical steroids in the management of dermatitis;

The use of inhaled bronchodilators in the treatment of asthma;

The insertion of pessaries containing clotrimazole in the treatment of vaginal candidiasis.

Topical administration has also become a popular way of introducing drugs into the systemic circulation through the skin. The development of transdermal patches that contain drugs began with the introduction of a hyoscine-based product for the treatment of nausea in the early 1980s.

The market for such products has since grown to include a wide range of disease management areas including the prophylaxis of angina (glyceryl trinitrate), the treatment of chronic pain (fentanyl) and hormone replacement (oestrogens). While the use of transdermal drug administration is not without its problems - for example, some preparations can cause local skin reactions - many patients find it a welcome alternative to taking tablets.

Internal

Enteral: sublingual, per os, per rectum.

Powders, tablets, dragee, drops, mixtures, pills.

Current system shortcomings are:

1. long absorbtion in the intestine.

2. negative action of gastric, intestine juices, bile on the medicine.

3. not complete absorption of the medicine into the blood, hard to establish dosage.

Sublingual method is good – medicine is absorb and don’t ruined. Pass in the blood aside liver and digestive tractus. Quick acting medicine – pills, tablets, solutions. (validol, nitroglycerine).

Per rectum – resorbtive action on the organism and localized.

Date: 2014-12-29; view: 1219