Supercritical Fluid Extraction Combined with Ultrahigh Performance Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry for Determination of Extractables to Evaluate Compatibility of Drugs with Rubber Closures.

Biological activity and pharmacological efficacy of protein drugs may be affected by the compatibility between drug and packaging materials. The compatibility of rubber closures seal cap has become the focus of many studies due to its complicated formulation. Despite of the significance of the issue, currently, there is little available data about organic leachables in drugs which is also not comprehensive. Since the concentration of migrants in drug is usually low and the matrix is complicated, the establishment of overall profile of extractables is crucial for the characterization of leachables. Herein, the supercritical fluid extraction (SFE) method was used because of its great extraction capacity and efficiency for low to medium polar extractables in rubber stoppers. The SFE conditions were optimized by response surface methodology (RSM). Experimental results of the extract yield were close to the predicted values (R2 = 0.95). Then the extractables were qualitatively and quantitatively analyzed with ultrahigh performance liquid chromatography quadrupole time-of-flight mass spectrometry (UHPLC-QTOF MS). Finally, risk assessment was made by comparing predicted exposure with injection permitted daily exposure (pPDE) limit or threshold recommended by threshold of toxicological concern (TTC). The results showed that there are many extractables such as glyceride, fatty acids and derivatives, antioxidants, and degradation products. Among them degradation products were in the majority and content of 17 substances exceeded corresponding limits. Considering their unknown toxicology, more experiments are therefore needed to provide information on their toxicology and risk assessment. The study provides a reference for the compatibility of drugs, and quality supervision of pharmaceuticals packaging.