Intramuscular injection, design effects

Intravenous aqueous injections provide an excellent means of achieving a rapid therapeutic response. Parenteral product design, eg, vehicle and other excipient selection, as well as choice of route of adrninistration, can prolong therapeutic activity and increase onset times. Thus, oily solutions, suspensions, or emulsions can be adrninistered by subcutaneous or intramuscular routes to create prolonged effect, ie, depot injection (28). 

Route of Exposure. A toxin may enter the body in several ways. It may be ingested or inhaled, it may come into contact with the skin or eyes, or it may be administered by injection (typically intravenous, intramuscular, or subcutaneous injection). In occupational settings, the major routes of exposure which are of most concern are inhalation and contact. The lungs have an extensive blood supply designed for efficient absorption of oxygen and, therefore, toxins which enter the lungs by inhalation may easily reach the body s blood supply such toxins may, of course, also have local effect on the respiratory system. Similarly, the eyes have an extensive blood supply and may be a source of concern for systemic absorption as well as local effect. 

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