Secobarbital Oral Solution
» Secobarbital Oral Solution contains, in each 100 mL, not less than 417 mg and not more than 461 mg of secobarbital (C12H18N2O3), in a suitable, flavored vehicle.
Packaging and storage— Preserve in tight containers.
Identification— Place 10 mL of Oral Solution in a separator containing 20 mL of water, add 5 mL of 1 N sodium hydroxide, and extract with two 10-mL portions of chloroform, discarding the chloroform extracts. Add 5 mL of 3 N hydrochloric acid, and extract with two 25-mL portions of chloroform, filtering the extracts through paper into a beaker. Remove the chloroform by evaporation on a steam bath, and dry the residue at 105 for 2 hours: the residue so obtained meets the requirements of the Identification test under Secobarbital.
Alcohol content 611: between 10.0% and 14.0% of C2H5OH.
Assay—
Internal standard— Butabarbital.
Internal standard solution— Dissolve an accurately weighed quantity of Butabarbital in chloroform, and quantitatively dilute with chloroform to obtain a solution having a known concentration of about 0.7 mg per mL.
Standard preparation— Dissolve accurately weighed quantities of USP Secobarbital RS and Butabarbital in chloroform, and quantitatively dilute with chloroform to obtain a solution that contains, in each mL, known amounts of about 1.2 mg of USP Secobarbital RS and about 0.9 mg of Butabarbital.
Assay preparation— Transfer an accurately measured volume of Oral Solution, equivalent to about 22 mg of secobarbital, to a separator, add 1 mL of dilute hydrochloric acid (1 in 5), and extract with four 10-mL portions of chloroform. Filter the extracts through about 15 g of anhydrous sodium sulfate that is supported on a funnel by a small pledget of glass wool. Collect the combined filtrate in a 50-mL volumetric flask, wash the sodium sulfate with 5 mL of chloroform, dilute with chloroform to volume, and mix. Combine 4.0 mL of this solution with 2.0 mL of Internal standard solution in a suitable container, and reduce the volume to about 1.5 mL by evaporation, with the aid of a stream of dry nitrogen, at room temperature.
Chromatographic system and System suitability— Proceed as directed for Chromatographic System and System Suitability under Barbiturate Assay 361, the resolution, R, between secobarbital and butabarbital being not less than 3.0. [note—Relative retention times are, approximately, 0.6 for butabarbital and 1.0 for secobarbital.]
Procedure— Proceed as directed for Procedure under Barbiturate Assay 361. Calculate the quantity, in mg, of secobarbital (C12H18N2O3) in each mL of the Oral Solution taken by the the formula:
25(RU)(QS)(Ci) / V(RS)
in which V is the volume, in mL, of Oral Solution taken; and the other terms are as defined therein.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/Question Contact Expert Committee
Monograph Ravi Ravichandran, Ph.D.
Senior Scientist
1-301-816-8330
(MDPP05) Monograph Development-Psychiatrics and Psychoactives
Reference Standards Lili Wang, Technical Services Scientist
1-301-816-8129
RSTech@usp.org
USP32–NF27 Page 3543
Pharmacopeial Forum: Volume No. 28(2) Page 364
Chromatographic Column—
Chromatographic columns text is not derived from, and not part of, USP 32 or NF 27.