Validation of an HPLC Assay Method for Routine QC Testing and Stability Study of Compounded Low-Dose Capsules of Acetylsalicylic Acid

Abstract Background The intolerance to Acetylsalicylic Acid (ASA) can be detected by conducting oral provocation testing (OPT), which is to gradually introduce low doses of ASA. To perform this test, hospital pharmacies compound small batches of different low-dosage ASA capsules. This work aims to validate a method for fast HPLC-UV assay that allows routine quality control and physicochemical stability studies of capsules. Methods The chromatographic separation is performed using a C18 column Kinetex (100 A, 50×4.6 mm, 2.6 µm) equipped with a precolumn C18. Separation is achieved using a mobile phase composed of water-acetonitrile-orthophosphoric acid (68:32:0.2 v/v/v) at a flow rate of 0.8 mL/min and UV detection at 237 nm. Results Validation shows that the method was suitable for routine analysis and could be used to perform stability studies. Conclusions The 5, 25, 100 and 250 mg dosed capsules show acceptable stability over 12 months, while the 1 mg dosed capsule show an unacceptable degradation of more than 15 % after 3 months. Therefore, hospital pharmacy can plan the manufacture of capsules and anticipate the requests of doctors.