Tonicity agents dextrose

Tonicity agents are added to injectable preparations to prevent osmotic shock at the site of injection upon administration, and thereby reduce local irritation. Typical excipients used for tonicity adjustment include saline, glycerin, mannitol, dextrose, and trehalose. Tonicity is a colligative property that depends primarily on the number of dissolved particles in solution. Hence, the amount of tonicity agent to be added depends on the specific formulation. Typically, osmolality of 280 to 320mOsm is considered iso-osmotic. 

Dextrose is widely used in solutions to adjust tonicity and as a sweetening agent. Dextrose is also used as a wet granulation diluent and binder, and as a direct-compression tablet diluent and binder, primarily in chewable tablets. Although dextrose is comparable as a tablet diluent to lactose, tablets produced with dextrose monohydrate require more lubrication, are less friable, and have a tendency to harden. The mildly reducing properties of dextrose may be used when tableting to improve the stability of active materials that are sensitive to oxidation. 

Hypotonic ophthalmic solutions or suspensions can be rendered isotonic by the addition of tonicity agents such as sodium chloride, potassium chloride, dextrose, glycerol and buffering salts. As with other adjuvants, the formulator should give due consideration to possible interactions between the tonicity agent and other components of the formulation, including the drug itself. 

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