A proof of principle study using radiopharmaceuticals to quantify and localize container-content interactions in medical syringes.

The sorption of drugs onto their contents is a known phenomenon that is difficult to analyse precisely. The purpose of this study was to present a non-invasive method for locating and quantifying sorption phenomena using radiopharmaceuticals. Radiopharmaceutical are medicines armed with a radionuclide enabling quantification and imaging using dedicated scanners. The sorption of nine different radiopharmaceuticals on 2- and 3-part syringes was investigated. These syringes were filled with the studied radiopharmaceutical solutions and stored immobile for 3 h. At different times ranging from 0 to 180 min, 10 µL were taken from the syringes and the radioactivity of these samples was determined by a gamma counter. 5 radiopharmaceuticals exhibited no significant sorption at any time point in both 2 and 3-parts syringes, but 4 radiopharmaceuticals exhibited sorption losses varying from 20 to 33% after 3 h contact with 3-part-syringes, but no sorption on 2-part syringes at any time point. [99mTc]Tc-tetrofosmine Single Photon Emission Computed Tomography/Computed Tomography imaging indicated clearly that the interactions were located on the rubber plunger of the 3-part-syringes. The specific nature of radiopharmaceuticals allowed their use as an innovative method to quantify and localize drug sorption phenomena.

Environmental contamination with cytotoxic drugs in healthcare using positive air pressure isolators.

Occupational exposure to cytotoxic drugs of hospital personnel involved in their preparation and administration is a major issue: ever since the introduction of protective measures in recent decades, the handling of these drugs has always been referred to as an occupational health hazard. Isolator technology was one of the protective equipments aimed at providing safe handling, but it has not yet been studied regarding contamination. The present study evaluates surface contamination with four cytotoxic drugs [cyclophosphamide (CP), ifosfamide (IF), 5 fluorouracil (5FU) and methotrexate (MTX)] by wipe sampling in two hospital pharmacies. Wipe samples were taken from work surfaces both located inside and outside the isolators. In addition, working gloves, the surface of infusion bags filled with 5FU or CP, and gloves used in simulation of drug administration were analyzed. Contamination was routinely found inside the isolators but rarely outside the isolators, indicating that the isolator technology is offering good protection of the cytotoxic drug handlers as well as the environment during preparation. On the other hand, contamination was found on the surfaces of infusion bags and gloves in contact with infusion bags filled with cytotoxic drugs. Consequently, personal protective equipment is still recommended during the manipulation and administration of the drugs because of potentially contaminated drug vials and final products.

Carboplatin and oxaliplatin decomposition in chloride medium, monitored by XAS.

The stability of carboplatin and oxaliplatin aqueous solutions has been studied under different chloride ions concentration and pH conditions. For both compounds, we demonstrate the chloration of the platinum first coordination shell.

Cefpodoxime-proxetil hydrolysis and food effects in the intestinal lumen before absorption: in vitro comparison of rabbit and human material.

The luminal and mucosal deesterification of the prodrug ester cefpodoxime-proxetil was studied in human duodenal washings in vitro. Enzymatic hydrolysis of the ester, releasing the active third generation cephalosporin, was observed in luminal washing in the same way as it had previously been observed in the rabbit. Eserine and PMSF and HgCl(2) were potent inhibitors of cefpodoxime-proxetil hydrolysis in luminal washing, suggesting the participation of a cholinesterase in the hydrolysis of cefpodoxime-proxetil. These results are in agreement with our previous findings performed in the rabbit. Moreover, cefpodoxime-proxetil directly decreases the acetylcholinesterase activity when tested by a specific enzymatic method. These observations support the hypothesis that the partial oral bioavailability of cefpodoxime-proxetil results from hydrolysis by luminal cholinesterases. In vitro experiments run with rabbit duodenal washing with food components were compared with the pharmacokinetics of cefpodoxime-proxetil in humans. Amino acids, trace elements and vitamins were potent inhibitors for cefpodoxime-proxetil hydrolysis in duodenal washings. Otherwise, lipids (LTC and mixed LCT/MCT) did not interact. In the human, cefpodoxime-proxetil bioavailability is significantly enhanced when tablets are administered with food. The correlation found between animal results and human results in vitro for prospective investigation of a new prodrug ester could be very useful. An in vitro hydrolysis in intestinal animal washings could allow the potentially degraded condition and the food effect of the luminal tract to be assessed before absorption.