A mixture is a liquid preparation intended for oral administration, in which the drug is dissolved, suspended or dispersed in a suitable vehicle. In general, several doses are contained in a bottle. A simple mixture contains only soluble ingredients. Advantages of a simple mixture are as follows:

1.  It can be given to children and geriatric patients having difficulty in swallowing tablets and capsules.
2. It has a faster onset of action.
3. The uniformity of dose is maintained.
4. It provides pleasant appeal to the patients.

However, a simple mixture suffers from the following drawbacks:

1. It has lesser stability than solid dosage forms.
2. It is difficult to mask the unpleasant taste of some drugs.
3. It is difficult to carry due to the bulk and weight.
4. Accidental breakage leads to complete loss.

Example

Weak iodine solution or tincture of iodine I.P.

 

	Iodine	2.0 g
	Potassium iodide	2.5 g
	Alcohol (50% v/v in water) (q.s.)	100 ml

Potassium iodide and iodine react together to form polyiodides, which enhance the solubility and provide a more stable solution. Potassium iodide and iodine are triturated in a pestle and mortar with sufficient quantity of 50% alcohol. After complete solubilization of iodine, more vehicle is added to make up the volume to the required level.