Lamotrigine oral liquid suspension and use thereof

1. A method for treating at least one of a neurological disorder and a mental disorder in a subject, the method comprising administering to a subject suffering from the disorder, 0.1 to 25.0 mL of an oral liquid suspension comprising:

(a) 3,5-diamino-6-(2,3-dichlorophenyl)-as-triazine (lamotrigine), present in 10±1 mg/mL;

(b) water;

(c) glycerin;

(d) propylene glycol;

(e) polyethylene glycol;

(f) methylparaben;

(g) sodium benzoate;

(h) sorbitol;

(i) saccharin;

(j) sucralose;

(k) xanthan gum;

(l) carboxymethyl cellulose;

(m) sodium phosphate; and

(n) microcrystalline cellulose and colloidal silicon dioxide.

2. The method of claim 1 , wherein the neurological disorder comprises epilepsy.

3. The method of claim 1 , wherein the mental disorder comprises bipolar disorder.

4. The method of claim 1 , wherein the at least one of a neurological disorder and a mental disorder comprises at least one of (a)-(c):

(a) epilepsy for a subject aged 2 years or older in adjunctive therapy for the treatment of:

A partial-onset seizures,

primary generalized tonic-clonic seizures,

generalized seizures of Lennox-Gastaut syndrome;

(b) epilepsy for a subject aged 16 years and older, undergoing conversion to monotherapy, with partial-onset seizures who are receiving treatment with carbamazepine, phenytoin, phenobarbital, primidone, or valproate as the single antiepileptic drug; or

(c) bipolar disorder for a subject, being treated for acute mood episodes with standard therapy, to delay the time to occurrence of mood episodes.

5. The method of claim 1 , wherein the lamotrigine present in the oral liquid suspension has the following particle size distribution (PSD):

D 90 of not more than 200 microns,

D 50 of not more than 100 microns, and

D 10 of not more than 30 microns.

6. The method of claim 1 , wherein the lamotrigine present in the oral liquid suspension has the following particle size distribution (PSD):

D 90 of not more than 140 microns,

D 50 of not more than 63 microns, and

D 10 of not more than 26 microns.

7. The method of claim 1 , wherein the oral liquid suspension has a viscosity at 25° C. of 100-200 mPs.

8. The method of claim 1 , wherein the oral liquid suspension has a viscosity at 25° C. of 117.5±10 mPs.

9. The method of claim 1 , wherein the oral liquid suspension has a pH of 6.5-8.0.

10. The method of claim 1 , wherein the oral liquid suspension has a pH of 7.1-7.2.

11. The method of claim 1 , wherein the oral liquid suspension has a specific gravity of not more than 1.2.

12. The method of claim 1 , wherein the oral liquid suspension has a specific gravity of not more than 1.03.

13. The method of claim 1 , wherein the oral liquid suspension further comprises a flavoring agent.

14. The method of claim 1 , wherein the oral liquid suspension further comprises cherry flavor as a flavoring agent.

15. The method of claim 1 , wherein the oral liquid suspension further comprises a coloring agent.

16. The method of claim 1 , wherein the oral liquid suspension further comprises FD&C red #40 and FD&C yellow #6 as a coloring agent.

17. The method of claim 1 , wherein the oral liquid suspension comprises:

1±0.1% w/v 3,5-diamino-6-(2,3-dichlorophenl)-as-triazine (lamotrigine)

84.75±8.5% w/v water

3.25 ±0.33% w/v glycerin (99% natural)

2.25 ±0.23% w/v propylene glycol

3.00 ±0.3% w/v polyethylene glycol 400

0.1 ±0.01% w/v methylparaben

0.03 ±0.003% w/v sodium benzoate powder

3.0 ±0.3% w/v 70% solution of sorbitol

0.08 ±0.008% w/v saccharin sodium dihydrate powder

0.75 ±0.08% w/v sucralose

0.20 ±0.02% w/v xanthan gum

0.10 ±0.01% w/v sodium carboxymethyl cellulose (medium viscosity, 2% aqueous solution at 25° C. 400-800 cPs)

0.03 ±0.01% w/v sodium phosphate dibasic (dried)

1.26 ±0.15% w/v microcrystalline cellulose and colloidal silicon dioxide

0.2 ±0.02% w/v cherry flavor

0.002 ±0.0002% w/v FD&C red #40

0.0002 ±0.00002% w/v FD&C yellow #6.

18. The method of claim 1 , wherein the oral liquid suspension has a volume of 0.2 mL, 0.5 mL, 2.5 mL, 10 mL, 15 mL, or 20 mL.

19. The method of claim 1 , wherein the oral liquid suspension, while packaged in a container, is essentially free from microbial growth for at least 24 months under ambient conditions.

20. The method of claim 1 , wherein the oral liquid suspension, while packaged in a container, is essentially free from Escherichia coli ( E. coli ) for at least 24 months under ambient conditions.

21. The method of claim 1 , wherein the oral liquid suspension, while packaged in a container, is essentially free from Burkholderia cepacia complex (BCC) for at least 24 months under ambient conditions.

22. The method of claim 1 , wherein the oral liquid suspension is an immediate release dosage form.

23. The method of claim 1 , wherein the oral liquid suspension is an immediate release dosage form that exhibits in-vitro dissolution rate more than 85% of drug release within 15 minutes, when said dosage form is placed in a dissolution vessel filled with 900 ml of 0.1N HCL, pH 1.2 maintained at 37±0.5° C. and stirred at a paddle speed of 50 rpm using a USP Type II (paddle) apparatus.

24. The method of claim 1 , wherein the oral liquid suspension is administered, such that

2±0.2 mg lamotrigine in 0.2 mL of the oral liquid suspension, or

5±0.5 mg lamotrigine in 0.5 mL of the oral liquid suspension, or

25±2.5 mg lamotrigine in 2.5 mL of the oral liquid suspension, or

100±10.0 mg lamotrigine in 10 mL of the oral liquid suspension, or

150±15.0 mg lamotrigine in 15 mL of the oral liquid suspension, or

200±20.0 mg lamotrigine in 20 mL of the oral liquid suspension is delivered to the subject.

25. The method of claim 1 , wherein upon administration under fasted conditions of a healthy adult subject with epilepsy taking no other medications, the oral liquid suspension exhibits a single-dose administration pharmacokinetic (PK) profile including:

AUC, 0→24 (micrograms per hour per ml) of 142;

Cmax (micrograms per ml) steady state of 7.93;

T max (h) of 2.79;

t 1/2 (h) of 32.8 (single dose); and

t 1/2 (h) of 25.4 (multiple dose).

26. The method of claim 1 , wherein relative to oral tablets or chewable dispersible tablets containing an equivalent amount of lamotrigine, administration of the oral liquid suspension results in a lower incidence, severity, and/or duration of adverse reactions including at least one of dizziness, headache, diplopia, ataxia, nausea, blurred vision, somnolence, rhinitis, pharyngitis, rash, vomiting, infection, fever, accidental injury, diarrhea, abdominal pain, tremor, backpain, fatigue, and xerostomia.