LAUSR

BACKGROUND Helicobacter pylori infection is a common cause of peptic ulcer disease and dyspepsia. In addition, it may result in gastric cancer and gastric mucosa associated lymphoid tissue lymphoma. First-line therapy usually is consisted of triple therapy containing Clarithromycin or Amoxicillin, one of the proton pump inhibitors and Metronidazole or Tinidazole. In addition to the triple therapy, an analgesic is required to relieve the pain such as; Naproxen. OBJECTIVE A sensitive and selective method need to be developed and validated for simultaneous determination of four drugs (Amoxacillin, Tinidazole, Naproxen and Lansoprazole) used for treating Helicobacter pylori in their combined dosage forms. METHODS With the aid of experimental design, the cited drugs were separated and quantified. HPLC with diode array detector was used and metronidazole was the internal standard which is one of the drugs used for that case also. A thermo Scientific BDS Hypersil C18 column (5 µm, 250 mm x 4.6 mm) with mobile phase composed of acetonitrile: water (40:60, v/v), pH = 5 adjusted with phosphoric acid at 30° C was used for the separation of the cited drugs. RESULTS The method was linear over concentration ranges 10-500 µg/mL for Amoxacillin, 10-350 µg/mL for Tinidazole, 10-250 µg/mL for Naproxen and 2-20 μg/mL for Lansoprazole. The proposed method was fully validated according to ICH guidelines. Statistical analysis revealed no significant difference between the results obtained and the four reference methods for investigated drugs. CONCLUSION The method can be easily implemented in quality control studies of the cited drugs in their dosage forms. HIGHLIGHTS Experimental design was applied using Plackett-Burman design for preliminary screening of factors followed by Box-Behnken design for chromatographic method optimization.