Process Research On Preparation Of Enrofloxacin Gelatin Microcapsules By Single Coacervation

The purpose of the present study was to develop the new formulation of enrofloxacin of intestinal slow-release, highly effective, long term, safe, drinking water conveniently, and decreased dosing frequency and bitterness. Single-factor test, screening tests of microcapsules orthogonal conditions and microwave drying conditions, and optimization of glutaraldehyde conditions were used to study the preparation process of enrofloxacin gelatin microcapsules using gelatin as load material by single coacervation technique. The results showed as follows:(1) The ratio of wall material to core material, gelatin concentration, stirring speed and temperature were detected by single-factor test. The results showed that the ratio was in the range 1:2 to 1:7, and the change of yielding rate was not significant; along with the decrease of the ratio of wall material to core material, drug loading had a decreased trend, and the entrapment rate and cost increased and then decreased,the entrapment rate was the highest(61.90%)while the ratio of wall material to core material was 1:5, therefore, the optimum ratio range of wall material to core material was 1:4 to 1:6. Moreover, while gelatin concentration was in the range of 2 percent to 10 percent, yielding rate and entrapment rate increased and then decreased, the entrapment rate was the highest (80.06%) while gelatin concentration was 4 percent, therefore, the optimum gelatin concentration was 3 percent to 5 percent. While the stirring speed was in the range 400r/min to 600r/min, the yielding rate increased initially and then decreased, and the average particle size of microcapsules decreased initially and increased. When the stirring speed was 450r per min, yielding rate was highest (79.28%) and the average particle size of microcapsules was minimum (39.63(?m), therefore, the optimum stirring speed range was 400r/min to 500r/min. When the temperature range was 40 ? to 60 ?, the yielding rate increased initially and then decreased, and the average particle size of microcapsules decreased,in addition, the yielding rate was highest (80.58%) while 50?, therefore, the optimum temperature range was 45 ? to 55 ?.(2) Via the orthogonal test of four factors and three levels on enrofloxacin gelatin microcapsules, the results showed that from big to small the factors to the comprehensive influence on the preparation of enrofloxacin gelatin microcapsules are the ratio of wall material to core material (R 14.457), gelatin concentration (R5.130), stirring speed (R3.403), and temperature (R1.877). Among them, the comprehensive score of the ratio of wall material to core material B3, gelatin concentration A2, stirring speed C3, and temperature D1 was highest. Therefore, by preparation process of B3A2C3D1, enrofloxacin gelatin microcapsules of yielding rate 81.53%, entrapment efficiency 81.90%, and the average particle size 36.43?m were gained.(3) Via the orthorhombic test of three factors and three levels on glutaraldehyde concentration, glutaraldehyde dosage and curing time of enrofloxacin gelatin microcapsules, the results showed that from big to small the factors to the comprehensive influence on the curing conditions of glutaraldehyde of the preparation of enrofloxacin gelatin microcapsules are the glutaraldehyde concentration, glutaraldehyde content and curing time. Among them, swelling ratio was 124.55%and encapsulation efficiency was 82.16% while the crosslinking degree of glutaraldehyde concentration A2, curing time C3 and glutaraldehyde content B2 reached 85 percent. Therefore, by preparation process of A2C3B2, enrofloxacin gelatin microcapsules of crosslinking degree79.19%, swelling ratio 124.55% and entrapment efficiency 82.16% were gained.(4) Via the screening experiment of different microwave drying conditions, the results showed that while the microwave drying condition was low power (6min), middle power (lmin), and med-high power (lmin), the entrapment efficiency was 84.24%, and the fast release was 2.54%, and the minimum angle of repose was 26.25°, and the comprehensive score of dispersion, surface smoothness and looseness was 80.49, therefore, to develop the enrofloxacin gelatin microcapsules of high entrapment efficiency(84.24%), uniform, round dispersion, and no bitterness, the optimum drying conditions was low power (6min), middle power (1min), and med-high power (1min).