In the preparation of powders, some special modifications are followed for incorporation of some of the substances. The modified procedures are as follows:

1. Hygroscopic and deliquescent powders: Substances such as sodium bromide, zinc chloride, etc., have strong affinity to absorb moisture from the atmosphere. When the moisture absorption crosses the limits, these substances even liquefy. Such substances are usually used in the granular form rather than powder form to expose the lower surface area to the atmosphere. These types of powders should be double wrapped.
2. Volatile substances: Agents containing volatile oils undergoes volatilization in the atmosphere upon incorporation in the powder. The examples of such agents are camphor, menthol, etc. These agents should be packed by double wrapping with an inner waxed paper and outer bond paper cover by using heat sealed plastic bags.
3. Eutectic powders: Substances having low melting point when triturated and mixed together will form a powder blend with low melting point as compared to individual melting points and whose temperature would be less than the room temperature and hence liquify. Examples of eutectic substances are thymol, menthol, camphor, phenol, aspirin, etc. The components of these powders should be dispensed separately with directions like powder of each kind should be taken as a dose. Another alternative method is by addition of double the proportion of an inert high melting point diluent such as magnesium carbonate, light magnesium oxide, kaolin or talc, etc., and mixing together with the eutectic substances without applying pressure.
4. Efflorescent powders: Crystalline substances, which liberate water of crystallization when present, cause a powder to liquefy. Examples of these substances are citric acid, ferrous sulfate, caffeine, etc. Employment of anhydrous salt of these substances is a remedy.
5. Liquids: Incorporation of liquids into a powder substance is done by trituration of the liquid (small concentration) with an equal volume of powder and then addition of the remaining powder in several portions with trituration.