Synthesis and pharmaceutical properties of N-acyloxymethyl prodrugs of Allop with potential anti-trypanosomal activity

An Injectable Oil-Based Depot Formulation of N-Acyloxymethyl Prodrug of Ropivacaine for Long-Acting Local Analgesia: Formulation Development and In Vitro/In Vivo Evaluation

Objectives: The development of novel long-acting injectables for local anesthetics is necessary to effectively manage the acute postoperative pain. The aim of this study was to prepare an injectable oil-based formulation of ropivacaine (ROP) prodrug (ropivacaine stearoxil, ROP-ST) and to investigate the pharmacokinetics and pharmacodynamics after injectable administration. Methods: A novel N-acyloxymethyl prodrug of ROP, i.e., ROP-ST, was synthesized and its physicochemical properties such as log P, solubility and stability characterized. A soybean oil-based depot of ROP-ST was prepared, and the in-vitro release of ROP-ST was evaluated using an "inverted-cup" method. Pharmacokinetic profiles and tissue retention properties were investigated after intramuscular administration of the formulation in rats. The analgesic efficacy was assessed via a von Frey monofilaments test by measuring the paw withdrawal thresholds. Results: The structure of ROP-ST was ascertained with clear 1H NMR assignment and accurate mass-to-charge ratio. The high Log P value of ROP-ST (9.16) demonstrated extremely low aqueous solubility, but the prodrug is biolabile when in contact with plasma or liver esterase. Intramuscular injection of ROP-ST oil solution in rats provided a significantly higher mean residence time without a very clear plasma peak of ROP. In a postoperative pain model of rats, the injection of ROP-ST oil solution into the vicinity of the sciatic nerve in the right ankle effectively controlled the postoperative pain for at least 72 h. Conclusions: The injectable oil-based depot formulation of N-acyloxymethyl prodrug of ROP may provide a new opportunity of long-acting local analgesia for postoperative pain.

A comprehensive review on potential candidates for the treatment of chagas disease

Twenty different infectious disorders induced by bacteria, viruses, and parasites are categorized as neglected tropical diseases (NTDs) by WHO. The severity of chagas disease remains a major concern in endemic areas and an emerging public health hazard in nonendemic countries. Trypanosoma cruzi, the etiological agent of this NTD, is mostly transmitted by triatomine vectors and comprises a range of epidemiologically significant variants. Current chemotherapeutics are obsolete, and one of the primary reasons for treatment cessation is their poor safety and effectiveness. Due to the aforementioned challenges, researchers are now focusing on discovering alternative novel safe, and economically reachable therapies for the treatment of trypanosomiasis. Certain target-based drugs that target specific biochemical processes of the causative parasites have been described as potential antichagasic agents that possesses various types of heterocyclic scaffolds. These flexible molecules have a wide range of biological actions, and various synthesized compounds with strong activity have been documented. This review aims to discuss the available literature on synthetic anti-T. cruzi drugs that will give a food for thought to medicinal chemists thriving to design and develop such drugs. Furthermore, some of the studies discussed herein are concerned with the potential of novel drugs to block new viable sites in T. cruzi.

New uses for old complexes: The very first report on the trypanocidal activity of symmetric trinuclear ruthenium complexes

This work reports on the trypanocidal activity of a series of symmetric triruthenium complexes combined with azanaphthalene ligands of general formula [Ru₃O(CH₃COO)₆(L)₃]PF₆ (L=(1) quinazoline (qui), (2) 5-nitroisoquinoline (5-nitroiq), (3) 5-bromoisoquinoline (5-briq), (4) isoquinoline (iq), (5) 5-aminoisoquinoline (5-amiq), and (6) 5,6,7,8-tetrahydroisoquinoline (thiq)). All complexes within the series presented in vitro trypanocidal activity against both the trypomastigote and amastigote forms of T. cruzi. The IC₅₀ values obtained for complexes 1-6 ranged from 1.39 to 165.9μM for the trypomastigote form and from 1.06 to 53.16μM for the amastigote form. These values were lower than the values observed for the metallic core [Ru₃O(CH₃COO)₆(CH₃OH)₃]⁺ itself and for the free ligands in all cases. Remarkably, complex 6 displayed lower IC₅₀ values than the reference drug (benznidazole) for the acute (trypomastigote form) and chronic (amastigote form) phases of Chagas disease. These findings, combined with the low toxicity against healthy cells (LLK-MK₂ strain) and a high SI value (Selectivity Index >10) make complex 6 an excellent candidate for in vivo tests.