Department of Pharmaceutics, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
Pharm Dev Technol. 2011 Jun;16(3):237-42. doi: 10.3109/10837451003610829. Epub 2010 Feb 11.
Radiation is efficient for terminal sterilization. Unfortunately, its use for liquid pharmaceuticals is difficult. This work investigated the potential radioprotective effect of self-microemulsifying (SMEDDS), microemulsions and their phase transition systems which were reported to enhance ocular drug delivery. Prednisolone solutions were prepared in SMEDDS, W/O microemulsions containing, 5% w/w (ME 5%) or 10% w/w (ME 10%) water, liquid crystalline system with 25% water (LC) and coarse emulsion containing 80% water (EM). These were subjected to gamma irradiation with aqueous solution and suspension being used as control. The physical properties of the formulations were monitored and the chemical potency of the drug was determined using a stability indicating HPLC method. The phase behavior of the formulations was not affected by irradiation but the viscosity of LC was significantly reduced. The SMEDDS, ME 5% and ME 10% showed excellent radiation protection as indicated by no change in the chemical potency. The LC retained 84% and the EM retained 39.8% of the chemical potency after exposure to 20 KGy. The aqueous solution was extensively degraded with the suspension retaining only 73.5% of the potency at 20 KGy. SMEDDS and W/O microemulsion can thus protect prednisolone from degradation by ionizing radiation.
辐射对于终端灭菌是有效的。不幸的是，它在液体药物中的应用较为困难。本工作研究了自微乳（SMEDDS）、微乳液及其相转变系统的潜在辐射防护作用，这些系统被报道可以增强眼部药物传递。将泼尼松龙溶液制备于 SMEDDS、含 5%w/w（ME5%）或 10%w/w（ME10%）水的 W/O 微乳液、含 25%水的液晶系统（LC）和含 80%水的粗乳剂（EM）中。将这些制剂用水溶液和混悬液进行γ射线照射，以水溶液和混悬液作为对照。监测制剂的物理性质，并使用稳定性指示 HPLC 方法测定药物的化学效力。制剂的相行为不受辐照影响，但 LC 的粘度显著降低。SMEDDS、ME5%和 ME10%表现出优异的辐射防护作用，表明化学效力没有变化。LC 在暴露于 20 kGy 后保留了 84%的化学效力，EM 保留了 39.8%的化学效力。水溶液在辐照下严重降解，混悬液在 20 kGy 时仅保留了 73.5%的效力。因此，SMEDDS 和 W/O 微乳液可以保护泼尼松龙免受电离辐射的降解。
