Development and Characterization of A New Dimethicone Nanoemulsion and its Application for Electronic Gastroscopy Examination.

PURPOSE: Although the effective and safe medical defoamers, dimethicone (DM) and simethicone (SM) are widely used in electronic gastroscope examination (EGE), their preparations are presented in the form of suspensions or emulsions, these are untransparent or milk-like in appearance and can easily cause misdiagnosis as a result of an unclear field of vision if the doctor does not master the amount of defoamer or operates incorrectly. At the same time, it is also difficult to wash out the camera and pipeline, due to the large oil droplets of preparations. The purpose of this study was to develop a new clear and transparent oil in water (O/W) DM nanoemulsions (DMNs) and observe the effect of application in EGE. METHODS: The oil phase was chosen for its antifoaming activity and viscosity. The emulsifier and co-emulsifier were selected according to the solubility of the oil phase in them. The water titration method was used to make the pseudoternary phase diagrams of nanoemulsions and optimize the prescription composition. DM-in-water nanoemulsion was prepared by the low energy method and evaluated for appearance, antifoaming ability, droplet size, and stability. The effect of DMNs utilized in EGEs was also observed. RESULTS: The optimal formulation of DMNs contained CRH-40 as an emulsifier, PEG-400 as a co-emulsifier, DM as oil phase with the viscosity of 10 mPa.s, and their proportion was 4.5:4.5:1, respectively. DMNs obtained the average particle size of 67.98 nm with the polydispersity index (PDI) of 0.332, and 57.14% defoaming rate. The result of using an EGE showed that DMNs were superior in comparison to the emulsions with regard to the defoaming effect, visual clarity, and easy cleanup. CONCLUSION: DMNs were found to provide excellent visual clarity to its other preparations. The novel DMNs is a promising substitute for DM emulsions or suspensions in EGEs.

[Content comparison of pinoresinol diglucoside in original and reborn bark of Eucommia ulmoides].

OBJECTIVE: To evaluate the reborn barks quality, antihypertensive effective component of pinoresnol diglucoside (PDG) in three times reborn barks were determined. METHODS: A YWG C18 column (10 microm, 250 x 4.6 mm) was used with a mobile phase of methanol-water (30:75) and flow rate of 1.0 (ml/min). The detective wave-length was set at 277nm and the column temperature at room temperature. RESULTS: PDG in the first reborn barks are slightly higher than the original ones, and in the second reborn barks are similar with the barks before girdling (the fist reborn barks), but in the third reborn barks, PDG are much lower than the barks before girdling (the second reborn barks). CONCLUSION: In order to ensure reborn barks quality, we suggest that the girdling bark regeneration can be made two times, the time between the first and the second girdling is not less than five years. PDG in the third reborn barks should be enhanced.