Preparation and Quality Control of Some Formulated Anticancer Radiopharmaceuticals

Abstract

umors are considered one of the most serious and widespread diseases in the world. World Health Organization (WHO) has reported that tumors affecting one-third of the world's population, where there is one person suffering from tumor for each three persons. Recent studies have shown that tumor is the second largest cause of death after heart disease, which caused a quarter of total deaths in 2000. The tumor cells are cells that have lost normal regulatory mechanisms that control the growth and reproduction leading to a high rate of proliferation of these cells which are spread excessively to be localized tumor invades surrounding healthy tissue. When tumor grows outside the blood vessels less oxygen required for the supply of these cells, leading to creation of diseased tissues that lack oxygen needed for them to carry out their functions which is expressed as (Hypoxia). Early detection of tumors helps to choose the appropriate treatment and the development of positive results for the patient. In the last decades a number of available invasive imaging methods have been used to determine the location of the tumor, however such methods were not suitable for routine use, prompting the researchers to the discovery of other methods such as the use of radiation for imaging pharmaceuticals compounds labelled with radioisotopes. The evolution of the use of these compounds a major development in the field of nuclear medicine at both diagnosis and treatment, and it became clear the impact of the use of these compounds in the study of radiological diagnosis, which included all human diseases, especially tumors, and due to its image of giving kinetics to most parts of the body, but also, and more to infer the density of receptors in the biological organs. Radiopharmaceuticals consist of radioactive isotope and pharmaceutical ligand reliable as a carrier the radioactive isotope through their accumulation in a specific organ of the body depending on the pharmacological properties. The radioisotope, which in turn will emits the radiation required for the diagnosis or treatment process depending on the nuclear properties. Diagnostic radiopharmaceuticals require some of the characteristics to show high efficiency in diagnosis, including: ease of preparation, and the short half-life, and only gamma rays emission and the efficiency of their accumulation in the organ of interest (high T/NT ratio). It have been approved that the use of radiopharmaceuticals high efficiency in nuclear imaging compared to conventional means of magnetic resonance imaging (MRI) and CT scans, on which imaging depends on anatomical differences between healthy tissue and infected tumorized tissues, which cannot distinguish any differences in many cases, while the use of radiopharmaceuticals depends on differences in functional activities between healthy tissue and infected tissue cancer, leading to the detection of deviations in the biochemical and physiological processes in the early stages of diagnosis before experienced any anatomical changes. The use of modern techniques such as positron emission tomography (PET) and single photon emission computed tomography (SPECT), which it is known their sensitivity to follow up and imaging tumors. In radiopharmaceutical preparation, the search for an ideal formulation that has a high uptake in the tumor and good stability in vivo requires considerable effort. In the past radiolabelled monoclonal antibodies was used for imaging tumor, but they did not give the desired results because of their large molecular size, so they cannot effectively penetrate of tumors, in addition to its survival in the circulation for a long time and their accumulation in the liver, prompting the researchers to provide alternatives to the radiolabelled monoclonal antibodies, which have the same applications, but without those disadvantages.