Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Raebareli, 229010, India.
Department of Pharmaceutics, College of Pharmacy, University of Florida, Gainesville, FL32611, United States.
Curr Pharm Des. 2018;24(43):5129-5146. doi: 10.2174/1381612825666190215121148.
Approximately 40 % drugs in the market are having poor aqueous solubility related problems and 70 % molecules in discovery pipeline are being practically insoluble in water. Nanocrystals is a prominent tool to solve the issue related to poor aqueous solubility and helps in improving the bioavailability of many drugs as reported in the literature. Nanocrystals can be prepared by top down methods, bottom up methods and combination methods. Many patented products such as Nanocrystals®, DissoCubes®, NANOEDGE® and SmartCrystals ®, etc., are available, which are based on these three preparation methodologies. The particle size reduction resulted into unstable nanocrystalline system and the phenomenon of Ostawald ripening occurs. This instability issue could be resolved by using an appropriate stabilizers or combination of stabilizers. The nanosuspensions could be transformed to the solid state to prevent particle aggregation in liquid state by employing various unit operations such as lyophilisation, spray drying, granulation and pelletisation. These techniques are well known for their scalability and continuous nanocrystal formation advantages. Nanocrystals can be characterized by using scanning electron microscopy, transmission electron microscopy, atomic force microscopy, differential scanning calorimetry, fourier transform infrared spectroscopy, powdered x- ray diffraction and photon correlation spectroscopy. The downscaling of nanocrystals will enable rapid optimization of nanosuspension formulation in parallel screening design of preclinical developmental stage drug moieties. One of the most acceptable advantages of nanocrystals is their wide range of applicability such as oral delivery, ophthalmic delivery, pulmonary delivery, transdermal delivery, intravenous delivery and targeting (brain and tumor targeting). The enhancement in market value of nanocrystals as well as the amount of nanocrystal products in the market is gaining attention to be used as an approach in order to get commercial benefits.
约 40%的市售药物存在与较差的水溶性相关的问题，而在发现管道中的 70%的分子实际上在水中难溶。纳米晶体是解决与较差的水溶性相关的问题的重要工具，并有助于提高许多药物的生物利用度，这在文献中有报道。纳米晶体可以通过自上而下的方法、自下而上的方法和组合方法来制备。许多专利产品，如 Nanocrystals®、DissoCubes®、NANOEDGE®和 SmartCrystals®等，都是基于这三种制备方法。粒径减小会导致不稳定的纳米晶体系统，并且会出现奥斯特瓦尔德熟化现象。通过使用适当的稳定剂或稳定剂组合，可以解决这种不稳定性问题。通过使用各种单元操作，如冷冻干燥、喷雾干燥、造粒和制粒，可以将纳米混悬液转化为固态，以防止在液态中颗粒聚集。这些技术以其可扩展性和连续纳米晶体形成的优势而闻名。纳米晶体可以通过扫描电子显微镜、透射电子显微镜、原子力显微镜、差示扫描量热法、傅里叶变换红外光谱、粉末 X 射线衍射和光子相关光谱来表征。纳米晶体的细化将能够在临床前药物部分的平行筛选设计中快速优化纳米混悬剂配方。纳米晶体最被广泛接受的优点之一是其广泛的适用性，如口服给药、眼部给药、肺部给药、透皮给药、静脉内给药和靶向（脑和肿瘤靶向）。纳米晶体市场价值的提高以及市场上纳米晶体产品的数量增加，引起了人们的关注，将其作为一种获得商业利益的方法。
