Depth Profiling of 4-Acetamindophenol-Doped Poly(lactic acid) Films Using Cluster Secondary Ion Mass Spectrometry

• Published in: Analytical chemistry (Washington) Vol. 76; no. 11; pp. 3199 - 3207
• Main Authors: Mahoney, Christine M, Roberson, Sonya V, Gillen, Greg
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.06.2004
• Subjects: Acetaminophen - analysis; Acetaminophen - chemistry; Analytical chemistry; Biopolymers; Chemistry; Delayed-Action Preparations - chemistry; Exact sciences and technology; Ions; Lactic Acid - chemistry; Lactic Acid - metabolism; Mass spectrometry; Polyesters; Polymers - chemistry; Polymers - metabolism; Spectrometric and optical methods; Spectrometry, Mass, Secondary Ion - methods; Thin films; Drug; Lactic acid polymer; Drug delivery systems; Ionic cluster; Ion irradiation; Biodegradability; Depth profile; Doped materials; Polymer films; Secondary ion mass spectrometry; Feasibility; Theophylline
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac035532n

The feasibility of using cluster secondary ion mass spectrometry for depth profiling of drug delivery systems is explored. The behavior of various biodegradable polymer films under dynamic SF5 + primary ion bombardment was investigated, including several films doped with model drugs. The SF5 + depth profiles obtained from these biodegradable polymer films showed very little degradation in secondary ion signal as a function of increasing primary ion dose, and it was discovered that the characteristic ion signals for the polymers remained constant for ion doses up to ∼5 × 1015 ions/cm2. These results suggest that the polyester structure of the biodegradable polymers studied here allows for a greater ability to depth profile due to ease of main chain scission. Attempts were also made to depth profile through a series of poly(lactic acid) (PLA) films containing varying concentrations of the drug 4-acetamidophenol. The depth profiles obtained from these films show very little decrease in both the 4-acetamidophenol molecular ion and PLA fragment ion signals as a function of increasing SF5 + primary ion dose. Similar results were obtained with theophylline-doped PLA films. These results show that, in some drug delivery devices, it is possible to monitor the distribution of a drug as a function of depth by using cluster primary ion beams.