Dexamethasone is practically insoluble in water and sparingly soluble in alcohol.
Oral solutions containing 5 - 30% ethanol are commercially available in many countries.
Some tablet formulations disperse readily in water and are often scored allowing administration of fractional doses. The use of the injection (dexamethasone sodium phosphate) diluted in flavoured syrup has been suggested.1 However, the oral bioavailability of dexamethasone sodium phosphate may be less than that of dexamethasone.2
If an oral liquid is required Formula A is preferred but Formula B is a suggested alternative.
Formula A3
Dexamethasone 1mg per mL |
| |
| Dexamethasone powder |
100 |
mg |
| Ethanol 95% |
15 |
mL |
| Propylene glycol |
20 |
mL |
| Glycerol |
50 |
mL |
| Rasberry essence |
0.5 |
mL |
| Saccharin sodium B.P. |
300 |
mg |
| Water |
to 100 |
mL |
| |
|
Expiry: 30 days |
| |
|
Stability: Chemically stable for 26 weeks. |
| |
|
Storage: Amber container (glass used in the study) at a temperature not exceeding
25°C. |
| |
|
Shake well before use |
| |
|
|
|
NOTE
- A similar preparation made from tablets may be less stable due to the effects of tablet excipients.
Formula B
Dexamethasone Mixture |
| |
| Dexamethasone tablets |
qs |
|
| Ethanol 95% |
15 |
mL |
| Glycerol |
50 |
mL |
| Parabens |
0.1 |
% |
| Water |
to 100 |
mL |
| |
|
Expiry: 7 days |
| |
|
Storage: Refrigerate |
| |
|
Shake well before use |
| |
|
|
|
REFERENCES
- Canadian Society of Hospital Pharmacists. Extemporaneous oral liquid dosage
preparations. Toronto, Ontario: CSHP; 1988.
- Fleisher D, Johnson KC, Stewart BH, Amidon GL. Oral absorption of 21-corticosteroid
esters: A function of aqueous stability and intestinal enzyme activity and distribution.
J Pharm Sci 1986; 75(1): 934-39.
- Accordino A., Chambers R., Thompson B. A short-term stability study of an oral solution
of dexamethasone. Aust J Hosp Pharm 1994, 24(4); 312-316.
|