Bala Indu, Hariharan Sarita, Kumar M N V Ravi
Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Punjab, India.
Crit Rev Ther Drug Carrier Syst. 2004;21(5):387-422. doi: 10.1615/critrevtherdrugcarriersyst.v21.i5.20.
Nanoparticles represent drug delivery systems suitable for most administration routes. Over the years, a variety of natural and synthetic polymers have been explored for the preparation of nanoparticles, of which Poly(lactic acid) (PLA), Poly(glycolic acid) (PGA), and their copolymers (PLGA) have been extensively investigated because of their biocompatibility and biodegradability. Nanoparticles act as potential carries for several classes of drugs such as anticancer agents, antihypertensive agents, immunomodulators, and hormones; and macromolecules such as nucleic acids, proteins, peptides, and antibodies. The options available for preparation have increased with advances in traditional methods, and many novel techniques for preparation of drug-loaded nanoparticles are being developed and refined. The various methods used for preparation of nanoparticles with their advantages and limitations have been discussed. The crux of the problem is the stability of nanoparticles after preparation, which is being addressed by freeze-drying using different classes of lyoprotectants. Nanoparticles can be designed for the site-specific delivery of drugs. The targeting capability of nanoparticles is influenced by particle size, surface charge, surface modification, and hydrophobicity. Finally, the performance of nanoparticles in vivo is influenced by morphological characteristics, surface chemistry, and molecular weight. Careful design of these delivery systems with respect to target and route of administration may solve some of the problems faced by new classes of active molecules.
纳米颗粒代表适用于大多数给药途径的药物递送系统。多年来，人们探索了多种天然和合成聚合物来制备纳米颗粒，其中聚乳酸（PLA）、聚乙醇酸（PGA）及其共聚物（PLGA）因其生物相容性和可生物降解性而受到广泛研究。纳米颗粒可作为多种药物的潜在载体，如抗癌剂、抗高血压剂、免疫调节剂和激素；以及核酸、蛋白质、肽和抗体等大分子。随着传统方法的进步，可用的制备方法有所增加，并且正在开发和完善许多制备载药纳米颗粒的新技术。已经讨论了用于制备纳米颗粒的各种方法及其优缺点。问题的关键在于制备后纳米颗粒的稳定性，这可通过使用不同种类的冻干保护剂进行冷冻干燥来解决。纳米颗粒可设计用于药物的靶向递送。纳米颗粒的靶向能力受粒径、表面电荷、表面修饰和疏水性的影响。最后，纳米颗粒在体内的性能受形态特征、表面化学和分子量的影响。针对靶点和给药途径对这些递送系统进行精心设计，可能会解决新型活性分子面临的一些问题。
