A New Zealand standardised formulation is available Formula
and Batch Sheet
This formula uses Ora-Blend/SF or Ora-Plus and Ora-Sweet/SF; 1:1, and has
been approved by the Extemporaneous Compounding Pharmacists' Group.
Alternatives are given below.
Baclofen has solubilities of 750mg
per 100mL in water and 2.4mg per 100mL in ethanol.
Baclofen liquid (Lioresal®) is available
in some countries.
Formulas A and B are based on published studies. Formula C is
based on published stability information and may be used if the commercial
suspending bases are not available or if a preparation with a syrup content
lower than formula A is preferred.
Formula
A1
Baclofen 5mg per mL |
|
| Baclofen
(Lioresal®)
tablets 20mg |
15 |
|
| Glycerol |
qs |
|
| Syrup |
to 60 |
mL |
|
|
Grind tablets, add sufficient glycerol to wet the
powder and form a fine paste. Gradually
add syrup to volume. |
|
| Expiry: 30
days. |
|
| Storage: Refrigerate. Protect
from light. |
|
| Shake
well before use. |
|
Notes
- If
unpreserved syrup is used add 0.1% parabens.
- The
formula was pleasant tasting with no after taste.
|
| |
|
|
|
Formula
B2
Baclofen Suspension 10mg per mL |
|
| Baclofen
tablets 10mg |
120 |
|
| *Vehicle |
to 120 |
mL |
|
*
Vehicle
A 1:1 mixture of Ora Sweet and Ora Plus, or a 1:1
mixture of Ora Sweet SF and Ora
Plus, or cherry syrup (cherry syrup concentrate
diluted 1:4 with simple syrup). |
|
| Expiry: 30
days. |
|
| Stability:
These preparations are chemically stable
for 60 days but microbial testing and stability
under in use conditions were not evaluated. |
|
| Storage: Refrigerate. Protect
from light. |
|
| Shake
well before use. |
|
Note
- The
final pH of these formulations is 3.2 - 4.7.2
|
| |
|
|
|
Formula
C
Baclofen Liquid |
| |
| Baclofen
tablets |
qs |
|
| Glycerol |
20 |
mL |
| Syrup |
10 |
mL |
| Methylcellulose
1% |
50 |
mL |
| Parabens |
0.1 |
% |
| *Citric
acid |
qs |
|
| Water |
to 100 |
mL |
|
| *
If possible check the final pH. If necessary
add a small amount of citric acid (50 - 100mg)
to bring the final pH approximately in the range
4 - 5. |
|
| Expiry: 30
days. |
|
| Storage: Refrigerate. Protect
from light. |
|
| Shake
well before use. |
|
Note
- If
the strength is less than 5 - 7.5mg per
mL the baclofen should be in solution
but a suspending agent is recommended as drug
may be bound to insoluble excipients. The
drug's solubility in this system has not been
evaluated.
|
| |
|
|
|
REFERENCES
- Johnson C.E., Hart S.M.
Stability of an extemporaneously compounded baclofen oral liquid.
Am J Hosp Pharm 1993; 50: 2353-55.
- Allen L. V., Erickson M.
A. Stability of baclofen, captopril, diltiazem hydrochloride,
dipyridamole, and flecainide acetate in extemporaneously compounded
oral liquids.
Am J Health-Syst Pharm 1996; 53 (Sep 15); 2179-2184.
|