Microencapsulation of extract containing shikonin using gelatin-acacia coacervation method: a formaldehyde-free approach

The application of microcapsule for pharmaceutical dosage form for various drugs has received considerable attention in recent years due to its multiple advantages. The most frequently used crosslinking agent formaldehyde in the gelatin–acacia microencapsulation process was altered by glycerol in this study. The effect of various parameters such as the concentration of surfactant, concentration of gelatin and continuous phase pH condition on the microcapsule particle size distribution was experimentally investigated. It was shown that the optimum concentration for surfactant/oil ratio is 1/10 and gelatin/oil ratio is 1/5 in the pH condition of approximately 4–6 for the coacervation process. Results obtained from microscopy observation revealed that one core microcapsule prepared by 6% glycerol was no different from formaldehyde. Hence, glycerol was demonstrated to be a good potential non-toxic crosslinking material for the applications of encapsulated extract containing shikonin.