Proposal of an identification test for MIBI-TEC® lyophilized reagent using infrared spectroscopy

Abstract

Quality Control is part of the Good Manufacturing Practices (GMP) responsible for the evaluation and release of pharmaceutical components, including active ingredients and excipients, to assure compliance with the specifications in pharmacopoeias. GMP for radiopharmaceuticals is regulated by RDC N. 17/2010 and RDC N. 63/2009 (ANVISA) establishing the minimum quality standards in industrial manufacture. Pharmacopoeias have the specifications for lyophilized reagents (LR) labeled with 99mTc regarding radiochemical purity, biodistribution and, in case of parenteral use, bacterial endotoxins and sterility tests must be performed. In radiopharmaceutical monographs, the necessity of non radioactivity assays for releasing lyophilized reagents are not well described, but ANVISA requires assays to assure the quality of the lyophilized powder, as active ingredient quantification and identification assays, stannous ion quantification and moisture determination. Infrared (IR) spectroscopy is widely used for identification of substances, mainly raw materials. The aim of this work is to propose an identification assay for MIBI-TEC® LR powder using IR spectroscopy. MIBI-TEC® batches were produced at IPEN/CNEN-SP and about 2 mg of the LR powder were mixed with 200 mg KBr, pressed at 80 kgf during 5 minutes into the holder to obtain a transparent pellet. The pellet was placed in ABB IR spectrometer, FTLA 2000 model, and a spectrum in the medium infrared region of 450 to 4000 cm-1 was acquired using Grams software. Tetramibi cuprous tetrafluoroborate, stannous chloride dihydrate, cysteine hydrochloride monohydrate, sodium citrate and mannitol had their respective IR spectrum recorded and the main characteristic absorptions were established for each formulation component. In the MIBI-TEC® spectrum, it was possible to observe a well characterized absorption in 2193 cm-1 which represents the presence of C≡N binding of tetramibi cuprous tetrafluoroborate active ingredient, free of interference, indicating that IR spectrum can be used as identification assay of the LR.