|
Trimethoprim is practically insoluble in water (0.004mg
per mL, at room temperature).
The current recommendation using a base of methylcellulose and syrup is
based on the only published stability study.1
At present there are no data to support the use of Ora-Blend
or Ora-Plus/Ora-Sweet to prepare trimethoprim suspension.
Formula
1
Trimethoprim 10mg per mL |
|
| Trimethoprim
Tablets 100mg |
10 |
|
| Methylcellulose
1% |
50 |
mL |
| *Syrup
BP or NF |
50 |
mL |
|
Prepare 100mL of a mixture of equal parts methylcellulose
1% and syrup. Crush the trimethoprim
tablets and then slowly add the base whilst mixing. Make
up to volume. |
|
| *
A suspending base of methylcellulose 1 - 2%
without syrup can be used if preferred. |
|
| Expiry: 30
days from preparation. |
|
| Stability: 6
weeks at 25°C; 3 months at 4°C.1 |
|
| Storage: Amber,
plastic bottles. |
| |
|
|
|
Reference
Nahata M.C. Stability
of trimethoprim in an extemporaneous liquid dosage form. J
Ped Pharm Pract 1997; 2 (2): 82-4. |