Nitrazepam is practically insoluble in water and slightly soluble in alcohol. Most brands of nitrazepam tablets are scored and disperse in water. Simple suspensions of tablets in vehicles of syrup and methylcellulose have been described but there are no formal stability studies. Formula A is based on a published study.1 Formula B is an alternative suggestion intended for short term use.
Formula A1
Nitrazepam Solution 1mg per mL |
| |
| Nitrazepam powder BP |
100 |
mg |
| Ethanol 95% |
15 |
mL |
| Propylene glycol |
20 |
mL |
| Glycerol |
50 |
mL |
| Water |
to 100 |
mL |
| |
|
Expiry: 30 days |
| |
|
Stability:
Chemical stability was confirmed for at least nine months. |
| |
Storage: Refrigerate. Protect from light.
Amber glass bottles were used in the study. |
| |
|
Note: If nitrazepam tablets are used instead of powder, the preparation may not be
as stable due to the possible effects of tablet excipients. |
| |
|
|
|
Formula B
Nitrazepam Suspension 1mg per mL |
| |
| Nitrazepam tablets 5mg |
20 |
|
| Glycerol |
20 |
mL |
| Methylcellulose 1% |
50 |
mL |
| Parabens |
0.1 |
% |
| *Ethanol 95 % |
5 |
mL |
| Water |
to 100 |
mL |
| |
|
*The inclusion of ethanol is optional but addition will dissolve some or all of the nitrazepam
and may improve dose uniformity. |
| |
|
Expiry: 30 days. |
| |
|
Storage: Refrigerate. Protect from light. |
| |
|
Shake well before use. |
| |
|
|
|
REFERENCE
- Amadio M, Chambers R, McDonald C. The development of a paediatric nitrazepam oral
solution. Aust J Hosp Pharm 1993; 23 (1): 82 (Abstract).
|