The necessity for long-term treatments of chronic diseases has encouraged the development of novel long-acting parenteral formulations intending to improve drug pharmacokinetics and therapeutic efficacy. Lately, one of the novel approaches has been developed based on lipid-based liquid crystals. The lyotropic liquid crystal (LLC) systems consist of amphiphilic molecules and are formed in presence of solvents with the most common types being cubic, hexagonal and lamellar mesophases. LC injectables have been recently developed based on polar lipids that spontaneously form liquid crystal nanoparticles in aqueous tissue environments to create the in-situ long-acting sustained-release depot to provide treatment efficacy over extended periods. In this manuscript, we have consolidated and summarized the various type of liquid crystals, recent formulation advancements, analytical evaluation, and therapeutic application of lyotropic liquid crystals in the field of parenteral sustained release drug delivery.

慢性疾病长期治疗的必要性促进了旨在改善药物药代动力学和治疗效果的新型长效肠胃外制剂的开发。最近，一种基于脂质液晶的新方法被开发出来。溶致液晶 (LLC) 系统由两亲分子组成，在溶剂存在下形成，最常见的类型是立方、六方和层状中间相。最近开发了基于极性脂质的 LC 注射剂，它们在水性组织环境中自发形成液晶纳米颗粒，以原位产生长效缓释药库，可在较长时间内提供治疗效果。在这篇手稿中，我们对各种类型的液晶、最近的制剂进展、分析评估和溶致液晶在肠外缓释给药领域的治疗应用进行了总结和总结。