Myrtle Oil Enteric Capsule

In this paper, myrtle oil (MO) was as the model medicine.Do the research on the different methods (spray-drying, simple coacervation, complex coacervation) which were used to preparaing the MO-enteric microcapsules. Inspected the impact of various methods over the MO-enteric microcapsules preparation, optimized the prescription and handicraft, and evaluated the microcapsules which was preparaed by the optimization process prescription. With a view to preparation MO-enteric microcapsules with high drug loading capability (LC) and encapsulation efficiency (EE). The specific content is divided into the following sections:Established in vitro analysis of the MO-enteric microcapsules. The HS-GC method was developed for the assay of MO in vitro. The stability, specificity and reproducibility of the method were good. The solubility of MO in different pH was determined. The solubility of MO at the physiological pH range was very slightly soluble. The saturation vapor pressure of MO was measured, the linear equation:lnP=-2898.3/T+17.244, r=0.9967.The emulsion-spray drying method was applied to prepare MO-enteric microcapsules. Emphasizing the research on on the prescription factors, such as:the kind of emulsifier and plasticizer, the ratio of MO with eudragitⅡ, the concentration of eudragitⅡand the usage of anti-adhesive. In the procedure study, based on these monofactorial investigations, the optimization of the preparation parameters, such as:inlet temperature, spray pressure, MO/ eudragitⅡand concentration of eudragitⅡ, were performed by using orthogonal design and Z-score method which employed three indices including powder yield, LC and EE. The optimization preparation condition as follow:MO/eudragitⅡwas 0.3, the concentration of eudragitⅡwas 0.04 kg-mL-1,the usage of SiO2 was 0.01 kg·mL-1, the inlet temperature was 110℃, the outlet temperature was 80℃, spray pressure was 4M3·min-1, injection rate was 4mL·min-1.The results of three batches of validation test showed that:microcapsule surface was smooth, but had much splinter; the mean diameter was(2.54±0.32)μm; poor mobility; LC was (8.6±0.3)%, EE was(58.8±2.8)%.The adsorption-spray drying method was applied to prepare MO-enteric microcapsules. Single-factor study showed thatβ-CD had better adsorption ability to the MO compared to Mg, Al-hydrotalcite aluminum and magnesium silicate; in the further research, the results showed that when MO/β-CD ratio was 1:3, the LC and EE of microcapsules were good. The results of three batches of validation test showed that:microcapsules were spherical, the surface was folds; the mean diameter was (2.37±0.22)μm; poor mobility; LC was (8.2±0.4)%, EE was (45.3±2.3)%.The simple coacervation method was applied to prepare MO-enteric microcapsules. Evaluated the advantages and disadvantages of the prescription and technology mainly in LC, EE indicators for the inspection. In the procedure study was performed by using orthogonal design. The optimization preparation condition was:the concentration of wall material was 0.1 kg·L-1, the ratio of capsule material with MO was 6:1, cohesion time was 6 h and stirring speed was 200 rpm. Through three validation test, the results show that:microcapsules with smooth surface, less debris; the mean diameter was (4.51±0.44)μm; better mobility; LC was (10.7±0.6)%, EE was (82.4±4.6)%.The complex coacervation method was applied to prepare MO-enteric microcapsules. The conditions of the preparation parameters, such as:sodium alginate (SA) types, concentration of SA and concentration of chitosan(Ch), were performed by using single-factor test. In the procedure study, based on the monofactorial investigation, the optimization of the preparation parameters, such as:the concentration of sodium alginate and chitosan, the speed and time of cohesion, were performed by using orthogonal design. Final optimization prescription and process are as follows:the concentration of SA was 0.025 kg·L-1, concentration of Ch was 0.3 % kg·L-1, the cohesion speed was 5 ml·min-1 and the cohesion time was 60min. Through three batches of validation test, the results show that:the microcapsules with fold surface; particle size distribution more uniform, with an the mean diameter of (14.23±1.45)μm; poor mobility; LC was (11.3±0.4)%, EE was (73.6±2.5)%.Evaluated the stability of the three batches of MO-enteric microcapsules which preparaed through emulsion-spray drying method. The results show that in the factors test and accelerated test, there were no significant changes in LC and EE, only the color of microcapsules changed from white to light yellow or yellow. At room temperature for six months, the microcapsulations were no obvious changed. All the results prompted to pay attention to the preservation of antioxidant.