Berggren Jonas, Alderborn Göran
Department of Pharmacy, Uppsala University, Box 580, SE-751 23 Uppsala, Sweden.
Pharm Res. 2003 Jul;20(7):1039-46. doi: 10.1023/a:1024462306941.
The aim was to investigate the influence of polymer content and molecular weight on the morphology and heat- and moisture-induced transformations, as indicators of stability, of spray-dried composite particles of amorphous lactose and poly(vinylpyrrolidone) (PVP).
Amorphous lactose and composite particles of amorphous lactose with different contents and molecular weights of PVP were prepared by spray drying. The nanostructure of the particles was analyzed by x-ray powder diffractometry, the morphology by light microscopy and SEM, the glass transition temperatures (Tg), crystallization temperatures (Tc), heats of crystallization and melting temperatures by differential scanning calorimetry, and moisture-induced crystallizations gravimetrically and by microcalorimetry.
All the types of particles prepared were amorphous. The Tg was unchanged or only marginally increased as a result of the inclusion of PVP. However, crystallization temperature, time to moisture-induced crystallization, and particle morphology were affected by both content and molecular weight of PVP.
Increased content and molecular weight of PVP may have the potential to increase the physical stability of amorphous lactose. However, Tg seems not to be a relevant indicator for the stability of this type of amorphous composite materials.
旨在研究聚合物含量和分子量对喷雾干燥的无定形乳糖与聚（乙烯基吡咯烷酮）（PVP）复合颗粒的形态以及热和水分诱导转变（作为稳定性指标）的影响。
通过喷雾干燥制备无定形乳糖以及具有不同PVP含量和分子量的无定形乳糖复合颗粒。通过X射线粉末衍射分析颗粒的纳米结构，通过光学显微镜和扫描电子显微镜分析形态，通过差示扫描量热法分析玻璃化转变温度（Tg）、结晶温度（Tc）、结晶热和熔点，并通过重量法和微量热法分析水分诱导的结晶。
制备的所有类型颗粒均为无定形。由于加入PVP，Tg不变或仅略有增加。然而，结晶温度、水分诱导结晶的时间以及颗粒形态受PVP的含量和分子量影响。
PVP含量和分子量的增加可能具有提高无定形乳糖物理稳定性的潜力。然而，Tg似乎不是这类无定形复合材料稳定性的相关指标。
