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. |
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|
Expiry: 30 days. |
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|
Storage: Refrigerate. Protect from light. |
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|
Shake well before use. |
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Notes
- If unpreserved syrup is used add 0.1% parabens.
- The formula was pleasant tasting with no after taste.
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| |
|
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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). |
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|
Expiry: 30 days. |
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|
Stability:
These preparations are chemically stable for 60 days but microbial testing and stability
under in use conditions were not evaluated. |
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|
Storage: Refrigerate. Protect from light. |
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|
Shake well before use. |
| |
Note
- The final pH of these formulations is 3.2 - 4.7.2
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| |
|
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|
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. |
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|
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.
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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.
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