Target fishing reveals PfPYK-1 and PfRab6 as potential targets of an antiplasmodial 4-anilino-2-trichloromethylquinazoline hit compound

We present investigations about the mechanism of action of a previously reported 4-anilino-2-trichloromethylquinazoline antiplasmodial hit-compound (Hit A), which did not share a common mechanism of action with established commercial antimalarials and presented a stage-specific effect on the erythrocytic cycle of P. falciparum at 8 < t < 16 h. The target of Hit A was searched by immobilising the molecule on a solid support via a linker and performing affinity chromatography on a plasmodial lysate. Several anchoring positions of the linker (6,7 and 3') and PEG-type linkers were assessed, to obtain a linked-hit molecule displaying in vitro antiplasmodial activity similar to that of unmodified Hit A. This allowed us to identify the PfPYK-1 kinase and the PfRab6 GTP-ase as potential targets of Hit A.

Stability Studies of Antipyocyanic Beta-Lactam Antibiotics Used in Continuous Infusion

In intensive care, beta-lactams can be reconstituted in 50 mL polypropylene syringes with NaCl 0.9 % and administered for 8 to 12 h at various concentrations with motor-operated syringe pumps. The feasibility and/or the stability of these antibiotic therapies are often poorly known by clinicians. The purpose of this study was to determine the stability of seven antipyocyanic beta-lactam antibiotics and cilastatin under real-life conditions. Stability indicating HPLC methods allowing quantification in pharmaceutical preparations and subsequent stability studies were performed. The stability studies showed that continuous infusion of piperacillin/tazobactam 80/10 mg/mL, of cefepime 20 and 40 mg/mL and of aztreonam 40 and 120 mg/mL can be used over 12 h. Moreover, continuous infusion of cefepime 120 mg/mL can be used over 10 h, whereas meropenem 10 and 20 mg/mL and ceftazidime 40 mg/mL remained stable only over 8 h, and meropenem 40 mg/mL was significantly degraded after 6 h. Finally, imipenem/cilastatin 5/5 mg/mL and piperacillin/tazobactam 320/40 mg/mL should not be used as continuous infusion. These data allow the establishment of protocols of administration of antipyocyanic beta-lactams by continuous infusion. Some of them are not appropriate to this mode of administration (imipenem/cilastatin, piperacillin/ tazobactam 320/40 mg/mL) or must be avoided if possible (ceftazidime 40 mg/mL).

Stability studies of five anti-infectious eye drops under exhaustive storage conditions

Several ocular infections require anti-infectious eye drops prepared by hospital pharmacy. Stability of these preparations is described in the literature, but studies do not always adequately consider physico-chemical parameters or storage conditions. We describe herein a complete study conducted on five anti-infectious eye drops containing vancomycin, gentamicin, ceftazidime, amphotericin B and voriconazole. We looked for significant changes in active pharmaceutical ingredient content, pH, osmolality and subvisible particles. Our study was designed to monitor stability at ambient temperature, at 2-8 °C, and also at 2-8 °C after various freezing periods. Under ambient storage conditions, eye drops were stable for 15 days, except for ceftazidime, which was stable for less than 1 day only. Under refrigeration conditions (2-8 °C), amphotericin B and voriconazole were stable for 60 days, vancomycin and gentamicin were stable for 30 days while ceftazidime was only stable for 15 days. After 90 days freezing and thawing, voriconazole remained stable at 2-8 °C for 60 days, vancomycin and amphotericin B for 30 days and gentamicin only for 21 days. Ceftazidime eye drops were stable for only 7 days at 2-8 °C after 60 days freezing. Our results are compared to the most relevant publications. Results of this study allow the compounding of large batches of harmonized anti-infectious eye drops.