A Multi-Platform Strategy Applied to the Detection and Characterization of Falsified Artemisinin Combination Therapies

P. DWIVEDI; M.J. CULZONI; M. EL-SHERBINY; O. ONWUJEKWE; P. EZEOKE; N. MALIK; I. FADEYI; H. KAUR; F.M. FERNÁNDEZ

Congreso; 61st ASMS Annual Conference; 2013

Introduction (116/120 words) Malaria is a serious public health problem with an estimated 216 million cases per year. However, production, distribution, and sale of falsified drugs are widespread and pose an immense regulatory challenge, potentially increasing antimalarial drug-resistance. Consequently, assessment of the prevalence of poor quality drugs is essential to understand the reasons for success or failure of frontline malaria treatment programs. To confirm the quality of Artemisinin Combination Therapies (ACTs) acquired through a pilot study in Enugu (Nigeria), liquid chromatography (LC), ambient mass spectrometry (MS), ion mobility spectrometry (IMS), X-ray diffraction (XRD), and nuclear magnetic resonance (NMR) were applied, allowing the detection of falsified medicines containing previously unseen ?wrong? ingredients instead of the stated active pharmaceutical ingredients (APIs). Methods (117 words) Two hundred ACTs and 10 mono-therapies were collected from pharmacies, market vendors, hospitals and a market stall through a convenience sampling strategy in Enugu city (Nigeria), in June 2012. Liquid chromatography results were confirmed using direct analysis in real time mass spectrometry (DART-MS) performed on a Bruker micrOTOF-Q I mass spectrometer equipped with a DART-100 source (IonSense, Saugus). Suspected falsified drugs were further characterized using 1) high-resolution proton and DOSY nuclear magnetic resonance (NMR) on a Bruker DMX 400 system, 2) X-ray powder diffraction (XRD), and 3) high resolution tandem MS analysis on a high definition Synapt G2 TOF MS system (Waters Corporation) with ultrahigh performance liquid chromatography (UHPLC) and/or travelling wave ion mobility spectrometry (TWIMS) separation. Preliminary data (255/300 words) High throughput DART-MS analysis of drug samples was performed to screen for the presence or absence of the stated APIs on the packaging of ACT samples collected in Enugu, Nigeria. Small amounts of the solid drug sample were coated on the surface of a melting point capillary which was introduced between the MS inlet and the DART ion source for sample desorption and ionization. Approximately 95% of the samples examined by LC, DART-MS and DART-MS/MS analyses confirmed the presence of the correct API(s). Detected API were artemether, artesunate, dihydroartemisinin, lumefantrine, piperaquine, amodiaquine, and naphthoquine. However, ~ 5% of the samples analyzed by LC and then DART-MS showed the absence of the correct API, even at various DART gas temperatures. MS and MS/MS analysis indicated the presence of other active/inactive pharmaceuticals such as acetaminophen, ciprofloxacin and plasticizers. Absence of the API in these potentially falsified medicines was confirmed by 1H NMR analysis with deuterated dimethyl sulfoxide (DMSO-d6) as solvent. In addition, preliminary examination of the Diffusion Ordered Spectroscopy (DOSY) NMR analysis of suspected drugs suggested the presence of various polymeric materials in the falsified drugs. Additional NMR experiments using deuterated water and deuterated chloroform are underway to characterize sample components that did not dissolve in DMSO-d6. UHPLC separation and/or TWIMS separation prior to ultrahigh resolution TOF-MS/MS analysis are also being performed to overcome matrix interferences in DART and to identify additional unknown chemicals/excipients in the samples. Through this study, the need and applicability of this multi-platform strategy for the analysis of pharmaceutical drug quality was demonstrated. Novel aspect (20 words) The ability of a multi-platform strategy to demonstrate the detection of falsified Artemisinin Combination Therapies (ACTs) is reported for the first time.