Amorphous solid dispersion (ASD) is one of the most effective formulation approaches to enhance the water solubility and oral bioavailability of poorly water-soluble drugs. However, maintenance of physical stability of amorphous drug is one of the main challenges in the development of ASD. Crystallization is a process of nucleation and crystal growth. The nucleation is the key factor that influences the physical stability of the ASD. However, a theoretical framework to describe the way to inhibit the nucleation of amorphous drug is not yet available. We reviewed the methods and theories of nucleation for amorphous drug. Meanwhile, we also summarized the research progress on the mechanism of additives influence on nucleation and environmental factors on nucleation. This review aims to enhance the better understanding mechanism of nucleation of amorphous drug and controlling over the crystal nucleation during the ASD formulation development.

Adult ; Female ; Humans ; Hypertension, Portal ; diagnosis ; etiology ; genetics ; Liver Cirrhosis ; complications ; diagnosis ; genetics ; Male ; Middle Aged ; Models, Statistical ; Nitric Oxide Synthase ; genetics ; Polymorphism, Genetic ; Prognosis ; Prospective Studies

ObjectiveTo investigate the effect of Jingangwan on the expression of osteoclast， c-Jun N-terminal kinase（JNK）， p38 mitogen-activated protein kinase（p38 MAPK）， and interleukin-1（IL-1） in the osteoporosis model rats， explore the mechanism of Jingangwan in the treatment of osteoporosis， and determine the optimal dosing concentration of Jingangwan. MethodFifty-six rats of SPF grade were randomized into a blank group，a sham operation group，a model group， model group，high-， medium-， and low-dose Jingangwan groups （0.72， 0.36， 0.18 g·kg^-1·d^-1， ig），and an estradiol valerate group （0.009 g·kg^-1·d^-1， ig）， with eight rats in each group. The rats in the model group， the blank group， and the sham operation group received 3 mL of normal saline， respectively. Samples were collected 12 weeks after drug administration. The number of osteoclasts was observed by tartrate-resistant acid phosphatase （TRAP） staining. Serum levels of JNK， p38 MAPK， and IL-1 were detected by enzyme-linked immunosorbent assay （ELISA）. The mRNA expression levels of p38 MAPK and JNK were detected by real-time quantitative polymerase chain reaction （Real-time PCR）. ResultThe TRAP staining results showed that compared with the model group， the estradiol valerate group and the Jingangwan groups could inhibit the formation of osteoclasts to different degrees. As revealed by ELISA results， compared with the model group and the sham operation group， the model group showed increased serum levels of p38 MAPK， JNK， and IL-1 （P<0.01）， while compared with the model group， all the groups with drug intervention showed decreased levels of p38 MAPK， JNK， and IL-1 （P<0.01）. The serum levels of JNK and IL-1 in the high-dose Jingangwan group were lower than those in the estradiol valerate group （P<0.05）. Real-time PCR results showed that compared with the blank group， the model group showed increased relative mRNA expression of p38 MAPK and JNK in the thighbone （P<0.01）， while compared with the model group， all the groups with drug intervention showed decreased relative mRNA expression of p38 MAPK and JNK in the thighbone （P<0.01）. ConclusionJingangwan can inhibit the formation of osteoblasts，reduce the diameter of the bone marrow cavity，improve bone quality，suppress the production of inflammatory factors，affect the metabolism of the MAPK signaling pathway，and blunt p38 MAPK and JNK activities to inhibit the differentiation and proliferation of osteoblasts and regulate bone metabolism， thereby preventing osteoporosis. Therefore，Jingangwan may be of application value in maintaining bone health and treating osteoporosis.