Method for enantiomeric purity of a quinuclidine candidate drug by capillary electrophoresis.
A chiral procedure based on EKC was developed and validated for determination of the enantiomeric purity of PHA-543613, a drug candidate that was under development for treatment of the cognitive deficits of Alzheimer's disease and schizophrenia. Separation of enantiomers is accomplished via differential, enantiospecific complexation with a single-isomer, precisely sulfated beta-CD and heptakis-6-sulfato-beta-CD (HpS-beta-CD). Both neutral and sulfated CDs were screened before selecting HpS-beta-CD as the chiral selector. The separation is conducted in a 61 cm x 50 microm uncoated fused silica capillary with 25 mM HpS-beta-CD in pH 2.50, 25 mM lithium phosphate as the separation buffer with detection at 220 nm. Application of reverse polarity at -30 kV results in an elution time of about 12 min for PHA-543613 and 13 min for the undesired S-enantiomer. Quantification is versus an authentic reference S-enantiomer as an external standard in combination with an internal standard. The procedure was validated over the range 0.1-2.0% w/w. The detection limit is 0.01-0.02%. The amount of distomer intrinsic to the drug substance is about 0.1% or less. The developed method was used to generate stability data on multiple lots: in one case for up to 3 years.
Ramstad
Tore
T
Pharmaceutical Sciences, Pfizer Corporation, Kalamazoo, MI 49001, USA. donna.s.socha@pfizer.com
Johnson
Rebecca L
RL
D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry / Q000302:isolation & purification* / Q000592:standards; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000379:methods / Q000592:standards / Q000706:statistics & numerical data; D019075:Electrophoresis, Capillary / Q000379:methods* / Q000592:standards / Q000706:statistics & numerical data; D018722:Nicotinic Agonists / Q000737:chemistry / Q000302:isolation & purification / Q000592:standards; D018697:Nootropic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000592:standards; D011812:Quinuclidines / Q000737:chemistry / Q000302:isolation & purification* / Q000592:standards; D012015:Reference Standards; D013237:Stereoisomerism
D019086:Bridged Bicyclo Compounds, Heterocyclic; C513163:N-(1-azabicyclo(2.2.2)oct-3-yl)furo(2,3-c)pyridine-5-carboxamide; D018722:Nicotinic Agonists; D018697:Nootropic Agents; D011812:Quinuclidines