Valproic acid syrup

M. Veerman, Excipients in valproic acid syrup may cause diarrhea A case report, DICP Ann. Pharmacother, 24, 832 (1990). 

The United States Pharmacopoeia [12] describes two tests for the identification of valproic acid in its formulations (capsules or syrup). 

Place a portion of capsules contents or place a volume of syrup, equivalent to about 250 mg of valproic acid, in a separator. Add 20 mL of 1.0 M sodium hydroxide shake and allow the layers to separate. Transfer the aqueous layer to a second separator, add 4.0 mL of hydrochloric acid, mix, and extract with 40 mL -heptane. Filter the w-heptane layer through glass wool into a beaker, and evaporate the... 

Procedure. Separately inject about 2.0 pL each of the standard preparation and the assay preparation, record the chromatograms, and measure the peak responses, for valproic acid and biphenyl peaks. Calculate the quantity, in mg, of C8H1602 in each mL of the syrup taken using the following formula ... 

Valproic acid syrup or capsule dosing The following table is a guide for the initial... 

Valproic Acid Syrup and Capsule Initial Dosing Guide ... 

Brand Name(s) (valproic acid) Depakene Brand Name(s) (valproate sodium) Depakene syrup... 

The sodium salt of valproate is marketed in Europe as a tablet and is quite hygroscopic. In Central and South America, the magnesium salt is available, which is considerably less hygroscopic. The free acid of valproate was first marketed in the USA in a capsule containing corn oil the sodium salt is also available in syrup, primarily for pediatric use. An enteric-coated tablet of divalproex sodium is also marketed in the USA. This improved product, a 1 1 coordination compound of valproic acid and sodium valproate, is as bioavailable as the capsule but is absorbed much more slowly and is preferred by many patients. Peak concentrations following administration of the enteric-coated tablets are seen in 3-4 hours. Various extended-release preparations are available not all are bioequivalent and may require dosage adjustment. 

Valproic acid is a carboxylic acid designated as 2-propyl-pentanoic acid. It is also known as dipropylacetic acid. Capsules and syrup are antiepileptics for oral administration. Each soft elastic capsule contains 250 mg valproic acid. 

Lithium carbonate (generic, Eskalith) (Note 300 mg lithium carbonate = 8.12 meq Li+.) Oral 150, 300, 600 mg capsules 300 mg tablets 8 meq/5 mL syrup Oral sustained-release 300, 450 mg tablets Valproic acid (generic, Depakene)... 

Valproic Acid Syrup Vitamin E Borosilicate glass, 2M X 4mm I.D. 2-5% liquid G2/S1AB 80-10 mesh) Nitrogen 245-265 EID Hexadecyl Hexadecanoate USP (24, pp. 1747 and 1749)... 

Pharmacokinetics. Valproic acid appears to be absorbed completely from available oral dosage forms when administered on an empty stomach. However, the rate of absorption differs among preparations. Peak concentrations occur in 0.5 to 1 hour with the syrup, 1 to 3 hours with the capsule, and 2 to 6 hours with the enteric-coated tablet. The extended-release formulation (Depakote-ER) is FDA approved for use in both patients with migraine headache and epilepsy. It should be noted, however, that the bioavailability of this formulation is approximately 15% less than that of enteric-coated divalproex sodium (Depakote). 

Valproic acid is available as a soft gelatin capsule, an enteric-coated tablet, a syrup, a sprinkle, an extended-release formulation... 

When nausea and vomiting occur in patients with any illness, a chronic oral medication may be temporarily replaced by the same active substance in a rectal dosage form so a hydrocortisone suppository may replace hydrocortisone in tablet or capsule a carbamaze-pine suppository may replace carbamazepine and a valproic acid suppository sodium valproate in syrup, tablet or capsule. 

---