Influence of Chitosan Concentration on Characteristic of Microspheres Delivery System Prepared from Eleutherine palmifolia (L.) Merr. Extract, Mutiah, Roihatul, Ardania Wirda, Suryadinata Arief, Megawati Dewi Sinta, Listiyana Anik, Wafi Abdul, and Annisa Rahmi , Pharmacognosy Journal, December 2022, Volume 14, Issue 6, p.702-709, (2022)