Abstract
The purpose of this study was to develop a system for sustained release of penicillin G (PenG) from alginate matrix microbeads for future application in subdermal implants. The beads containing penicillin G were prepared by extrusion method. Initially, different biopolymers were evaluated in combination with alginate. Sodium alginate (3 %,w/v) with different wall materials (maltodextrin, carboxymetilcellulose, pectin and octenyl succinic anhydride (OSA) modified starch at a concentration of 4 % (w/v) was dissolved in distilled water and a pre-calculated quantity of penicillin G was added (10 %, w/v). A 24-1 fractional factorial design was used to investigate the effects of alginate, OSA starch, CaCl2 concentration and times of gelation on retention percentage of penicillin in microspheres.
The retention percentage of penicillin was determined in the calcium chloride solution. The best results were obtained with alginate/OSA starch, with entrapment of 51.66 %. Experiments were designed to improve PenG entrapment in microbeads. The retention of PenG in alginate/ OSA starch matrix was optimized using a Central Composite Rotatable Design (23 full factorial design). The data indicates that high retention percentage of penicillin G (95.4 %) values was obtained when OSA starch concentration and gelation time were lower. The results obtained in the present study indicate that alginate with OSA starch are wall materials suitable for the microencapsulation of PenG.
