SPME–GC Determination of an Inhalation Anesthetic, Isoflurane in Bulk and Nanoemulsion Dosage Form

Abstract

A stability-indicating gas chromatographic (GC) method was developed and validated for quantitative determination of an halogenated volatile anesthetic isoflurane (ISO) in the presence of degradation products generated under stress conditions. The sample concentration was carried out by means of solid-phase microextraction (SPME) using a 100-μm polydimethylsiloxane (PDMS) fiber, desorbed inside the GC inlet port and analyzed using a GS-Gaspro (30 m × 0.32 mm) capillary column with flame ionization detection (FID). The response was linear over a range of 3.75 to 30.04 μg mL−1 (r = 0.9996). The specificity and stability-indicating capability of the method was verified subjecting ISO to hydrolytic, oxidative, photolytic, and thermal stress conditions. The method showed good recovery (99.54%) with low intra- and inter-day relative standard deviation (RSD) (≤2.5%). A considerable degradation occurred under stress conditions evidenced by an ISO peak area reduction while the degradation product was not detectable. There was no interference of the excipients in the determination of the drug. Thus, the proposed method was found to be stability-indicating and can be used for routine analysis for quantitative determination of ISO liquid anesthetic.