title: Evaluation of chemical and diastereoisomeric stability of S-adenosylmethionine in aqueous solution by capillary electrophoresis.
abstract: Capillary electrophoresis was used for monitoring the stability of S-adenosylmethionine in aqueous solution under different conditions of storage and incubation used for "in vitro" and "in vivo" experiments, by evaluating both the entity of degradation and the possibility of epimerization at the sulfonium group. The determination of S,S-S-adenosylmethionine in presence of its R,S-epimer and degradation products was performed in uncoated capillary of 50 microm ID using 150 mM sodium phosphate buffer at pH 2.5. The analyses were performed in short or long-end injection modes depending if a fast monitoring of the degradation products or the evaluation of the diastereoisomeric ratio were carried out, respectively. In the long-end injection mode the baseline separation of S-adenosylmethionine diastereoisomeric forms and degradation products was obtained in less than 10 min with efficiency values in the range of 172,520-311,439 number of theoretical plates per meter. The results showed that freezing was the optimum storage mode for S-adenosylmethionine aqueous solutions preserving from degradation and diastereoisomeric ratio alterations. Under incubation conditions at 38 degrees C during 14 days period S-adenosylmethionine showed a strong degradation and the formation of three main increasing degradation products. After 7 and 14 days only the 52% and 32% of the initial drug concentration were available and the active S,S-S-adenosylmethionine form was the most affected.
authors.affiliation: Istituto di Metodologie Chimiche, Consiglio Nazionale delle Ricerche, CNR, Area della Ricerca Roma 1, Via Salaria km 29,300, 00016 Monterotondo Stazione, Rome, Italy. claudia.desiderio@imc.cnr.it
authors.forename: Claudia
authors.initials: C
authors.lastname: Desiderio
authors.forename: Rosaria A
authors.initials: RA
authors.lastname: Cavallaro
authors.forename: Antonella
authors.initials: A
authors.lastname: De Rossi
authors.forename: Fabrizio
authors.initials: F
authors.lastname: D'Anselmi
authors.forename: Andrea
authors.initials: A
authors.lastname: Fuso
authors.forename: Sigfrido
authors.initials: S
authors.lastname: Scarpa
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004355:Drug Stability; D004356:Drug Storage / Q000379:methods; D019075:Electrophoresis, Capillary / Q000295:instrumentation / Q000379:methods*; D015203:Reproducibility of Results; D012436:S-Adenosylmethionine / Q000032:analysis* / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D013237:Stereoisomerism; D013678:Technology, Pharmaceutical / Q000379:methods; D013696:Temperature; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: D012996:Solutions; D014867:Water; D012436:S-Adenosylmethionine