Quality assessment for tramadol in pharmaceutical preparations with thin layer chromatography and densitometry

• Published in: Biomedical chromatography 2004-10, Vol.18 (8), p.589-599
• Main Authors: Krzek, Jan, Starek, Małgorzata
• Format: Article
• Language: English
• Subjects: Analgesics, Opioid - analysis; Chromatography, Thin Layer - methods; densitometric detection; Densitometry - methods; Drug Stability; drugs analysis; Hydrogen-Ion Concentration; impurity; Pharmaceutical Preparations - chemistry; Quality Control; Sensitivity and Specificity; Solutions; Temperature; thin-layer chromatography; Time Factors; tramadol; Tramadol - analysis
• ISSN: 0269-3879; 1099-0801
• DOI: 10.1002/bmc.361

Research studies have been carried out to develop a chromatographic and densitometric method suitable for identification and determination of tramadol and impurities. In addition, the stability of tramadol in solutions was investigated, including an effect of solution pH, temperature and incubation time. In the first instance the conditions for identification and quantitative determination of tramadol and impurities in pharmaceutical preparations were established. The separation was performed on silica gel‐coated chromatographic plates (HPTLC) using two mobile phases: (I) chloroform–methanol–glacial acetic acid (9:2:0.1, v/v/v); (II) chloroform–toluene–ethanol (9:8:1, v/v/v). The UV densitometry was carried out at λ = 270 nm. The developed method is of high sensitivity and low detection and determination limits ranging from 0.044 to 0.35 µg. For individual constituents the recovery ranges from 93.23 to 99.66%. The next step was to evaluate the stability of tramadol and determine a method of decomposition under various experimental conditions. It was found that tramadol decomposes in various ways in acidic and basic environments producing (1RS)‐[2‐(3‐methoxyphenyl)cyclohex‐2‐enyl]‐N,N‐dimethylmethanamine (imp. B) and (1RS, 2RS)‐2‐[(dimethylamino)methyl]‐1‐(3‐methoxyphenyl)cyclohexanol (imp. cis‐T) or imp. cis‐T, respectively. Copyright © 2004 John Wiley & Sons, Ltd.