Validacija ITLC metode za određivanje sadržaja radiohemijske nečistoće C u 99mTc-MIBI injekciji

Prisustvo radiohemijske nečistoće C u 99mTc-MIBI injekciji utiče na kvalitet skena, jer se radiofarmaceutik nedovoljno nakuplja u organu od interesa, dok je aktivnost okolnih organa i tkiva velika. Zbog toga je i doza zračenja koju prime okolni organi i tkiva iznad propisanih granica. Da bi se obezbedilo da je planirano izlaganje zračenju pacijenata svedeno na minimum, farmakopeja zahteva ispitivanje sadržaja radiohemijske nečistoće C u 99mTc-MIBI injekciji neposredno pre primene radiofarmaceutika u pacijenta. Za ova ispitivanja se koriste metode hromatografije. U radu je predstavljena brza i osetljiva ITLC metoda namenjena za rutinsko ispitivanje sadržaja radiohemijske nečistoće C u 99mTc-MIBI injekciji. ITLC metoda je validirana, a ispitivani su pogodnost sistema, tačnost, preciznost, ponovljivost, specifičnost, limit detekcije, limit kvantifikacije, linearnost, robustnost i osetljivost metode. Dobre "recovery" vrednosti i niska relativna standardna devijacija potvrđuju da je predložena ITLC metoda pogodna za rutinsko određivanje nečistoće C u 99mTc-MIBI u injekciji.
The European Pharmacopoeia mandates that all radiopharmaceuticals used in nuclear medicine for diagnostic and therapeutic purposes must be of the correct radiochemical and radionuclidic purity and have the correct radioactivity present at the stated time of injection to ensure that the intended radiation exposure of patients is kept to a minimum. These factors have an effect on the overall radiation dose to the patient, as impurities of the radionuclide and/or its chemical composition may affect the biodistribution of the injected radiopharmaceutical and consequently the radiation dose to any one particular organ or the whole body dose. The presence of radiochemical impurity C in 99mTc-MIBI injection affects the quality of the image, because 99mTc-MIBI accumulates insufficiently in the organ of interest, while the activity of the surrounding organs and tissues is high. Therefore, the radiation dose received by the surrounding organs and tissues is above the permitted level. In order to avoid unnecessary irradiation of surrounding organs and tissues, the pharmacopoeia requires examination of the content of radiochemical impurity C immediately before administering of 99mTc-MIBI to the patient. Chromatographic methods are used for these tests. The paper presents a fast and sensitive ITLC method intended for routine examination of the content of radiochemical impurity C in 99mTc-MIBI injection. The ITLC method was validated, and the suitability of the system, accuracy, precision, repeatability, specificity, limit of detection, limit of quantification, linearity, robustness and sensitivity of the method were examined. Good "recovery" values and low relative standard deviation confirm that the proposed ITLC method is suitable for routine determination of impurity C in 99mTc-MIBI in injection.