A Chemical Characterization Workflow for Nontargeted Analysis of Complex Extracts from Polymer Based Medical Device Using High Resolution LC/MS.

The chemical characterization of extractables and leachables (E&Ls) is an important aspect of biosafety and biocompatibility assessment in medical device industry. The advent of the body-contact use of medical devices in patient treatment has introduced a potential source for extractables and leachables as these medical devices are comprised of various polymeric materials. Several industry working groups, the FDA and USP, have recognized the guidance for chemical characterizations and nontargeted analysis of medical device extracts, such as ISO 10993-18:2020. The MS application of nontargeted analysis has played a critical role in understanding the E&Ls from medical device extracts. However, there have been very few reports about the MS based workflow with nontargeted analysis for medical device extracts and there is little guidance about the exact methodologies which should be used, even though there is an urgent need for a clearly defined process for the identification of medical device extracts. In this study, we demonstrated an analytical LC/MS (liquid chromatography/mass spectrometry) workflow using high resolution Exploris120 Orbitrap instrument for data acquisition and Compound Discoverer 3.3 intelligent software for data processing to profile the polymer related E&Ls from a balloon dilation catheter device extracted with 40% ethanol. An E&L ID workflow combining LC separation, data-informed MS acquisition strategy, MS information mining (including adduct ions, MS information from both electrospray ionization (ESI) (+) and ESI (-), in-source fragmentation, common fragment ions (CFIs), common neutral losses (CNLs), and in silico MS simulation was described with intelligent software processing and manual data interpretation. The workflow developed in this study was proven to be effective to provide a comprehensive profile of polymer related degradation products, polymer impurities and additives including surfactants, UV curing agent, antioxidants, and plasticizers for the device analyzed. The classification of E&L compounds using CFIs and CNLs was very effective to facilitate the identification of polymer related impurities and extract the polymer related impurities with common structures in a large data result set.

Chemical Characterization of Leachables in Catheter Device.

Extractables or leachables of biomaterials or residues of additives used in the manufacturing process that are potentially released from a medical device may have an adverse effect on a patient. Chemical characterization of leachable chemicals and degradation products in a medical device is an important aspect of its overall biocompatibility assessment process, which helps to ensure that the therapeutical benefits exceed the potential biological risks associated with the use of the device or its components or materials. By evaluating the types and amounts of chemicals that may migrate from a device to a patient during clinical use, potential toxicological risks can be assessed. A semipolar solvent, 40% ethanol in water (v/v), an appropriate surrogate for blood and blood related substances, was used as an extraction medium to mimic the body fluid in contact with a medical device. The extraction was conducted at 37 °C for 24 h for limited exposure medical devices per ISO 10993-12:2021. From gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS) analysis, leachable chemicals of polylactams, linear polyamides, cyclic polytetramethylene ether (PTME), poly(tetramethylene ether) glycol (PTMEG), cyclic and linear poly(tetramethylene ether) glycol adipate (PTMEGA), cyclic and linear poly(tetramethylene ether) glycol adipamide (PTMEGAA) were structurally elucidated. The workflow presented in this study was proven to be a successful approach for rapid extractable and leachable profiling and identification with confidence.

UV-visible spectroscopy as an alternative to liquid chromatography for determination of everolimus in surfactant-containing dissolution media: a useful approach based on solid-phase extraction.

High-throughput 96-well solid phase extraction (SPE) plate with C-18 reversed phase sorbent followed by UV-visible (UV-Vis) microplate reader was applied to the analysis of hydrophobic drugs in surfactant-containing dissolution media, which are often used to evaluate the in-vitro drug release of drug eluting stents (DES). Everolimus and dissolution medium containing Triton X-405 were selected as representatives, and the appropriate SPE conditions (adsorption, washing and elution) were investigated to obtain a practical and reliable sample clean-up. It was shown that the developed SPE procedure was capable of removing interfering components (Triton X-405 and its impurities), allowing for an accurate automated spectrophotometric analysis to be performed. The proposed UV-Vis spectrophotometric method yielded equivalent results compared to a classical LC analysis method. Linear regression analysis indicated that both methods have the ability to obtain test results that are directly proportional to the concentration of analyte in the sample within the selected range of 1.0-10 µg/ml for everolimus, with a coefficient of correlation (r(2)) value of >0.998 and standard deviation of the residuals (Syx) of <2%. The individual recoveries of everolimus ranged from 97 to 104% for the UV-Vis spectrophotometric method and from 98 to 102 for the HPLC method, respectively. The 95% CI of the mean recovery for the UV-Vis spectrophotometric method was 99-102% and for the HPLC method was 99-101%. No statistical difference was found between the mean recoveries of the methods (p=0.42). Hence the methods are free from interference due to Triton and other chemicals present in the dissolution medium. The variation in the amount of everolimus estimated by UV-Vis spectrophotometric and HPLC methods was ≤3.5%, and the drug release profiles obtained by both methods were found to be equivalent by evaluation with two-one-sided t-test (two-tailed, p=0.62; mean of differences, 0.17; 95% CI, 0.62-0.96) and similarity factor f2 (f2 value, 87). The excellent conformity of the results makes UV-Vis spectrophotometer an ideal tool for analyzing the drugs in the media containing surfactants, after SPE. The 96-well SPE plates in combination with UV-Vis microplate reader provide a high throughput method for the determination of in-vitro drug release profile of DES. Switching from HPLC to UV-Vis spectrophotometer microplate reader assay reduces the solvent consumption and labor required for the sample analyses. This directly impacts the profitability of the laboratory.