Forced Swim Alters the Radiolabeling of Blood Constituents from Wistar Rats

The present study investigated the effects of forced swimming on the technetium-99m (99mTc) labeling of blood constituents (BloCs). Rats (Wistar) were submitted to forced swim. In previous experiments, swimming animals would recover for different periods of time. Animals not submitted to swimming were used as control. Blood samples were obtained and the 99mTc labeling of BloCs was carried out. Blood cells (BCs), plasma (P), insoluble fractions (IF-P and IF-BCs), and soluble fractions (SF-P and SF-BC) were isolated. Radioactivity was determined, and the percentage of 99mTc incorporated (%ATI) was calculated in each fraction. Results showed that forced swimming decreased the percentage of 99mTc incorporated (%ATI) in IF-P (p < 0.05). It is suggested that the 99mTc labeling of BloCs could be used to verify the effects of the stress conditions on BloCs and that the radionuclide fixation on plasma proteins might be altered in rats submitted to acute stress induced by forced swimming, returning to control levels after recovery.

Determination of the worst case for cleaning validation of equipment used in the radiopharmaceutical production of lyophilized reagents for 99mTc labeling

ABSTRACT Cleaning validation, a requirement of the current Good Manufacturing Practices (cGMP) for Drugs, consists of documented evidence that cleaning procedures are capable of removing residues to predetermined acceptance levels. This report describes a strategy for the selection of the worst case product for the production of lyophilized reagents (LRs) for labeling with 99mTc from the Instituto de Pesquisas Energéticas e Nucleares (IPEN-CNEN/São Paulo). The strategy is based on the calculation of a "worst case index" that incorporates information about drug solubility, cleaning difficulty, and occupancy rate in the production line. It allowed a reduction in the required number of validations considering the possible manufacturing flow of a given product and the subsequent flow, thus facilitating the process by reducing operation time and cost. The products identified as "worst case" were LRs PUL-TEC and MIBI-TEC.