What is the difference between depot and aqueous preparations?

Answer 1

When drugs administered intramuscular route, absorption of drugs in a aqueous solution is fast,whereas that from depot preparations is slow.Specialized depot preparations-often a suspension of drug in a non aqueous vehicle such as polyethylene glycol.As the vehicle diffuses out of the muscle drug precipitates at the site of injection drug then dissolves slowly,providing a sustained-release dose-over an extended period of time.