Pectin-gelatin complex coacervates II: Effect of microencapsulated sulfamerazine on size, morphology, recovery, and extraction of water-dispersible microglobules.
Spherical medicated microglobules were prepared by complex coacervation of Type A gelatin with pectin, having nominal diameters of 5, 10, and 25 micron and containing 37.3, 44.9, and 45.2% (w/w) sulfamerazine, respectively. They were recovered as water-insoluble powders and were spontaneously revertible to highly disperse systems when reconstituted in water or physiological electrolyte solution. The conditions affecting microglobule formation were studied. For complete formation, the crystals must be dispersed at greater than or equal to pH 5. The effect of the sulfamerazine mass added on microglobule morphology, yield, and contents were investigated. As much as 37.3, 44.5, and 69.1% (w/w) sulfamerazine in 5-, 10- and 25-micron microglobules could be formed without loss of spherical shape. The microglobule yield versus drug-to-colloid ratio curves were nonlinear below the critical drug-to-colloid ratio for loss of sphericity. Addition of sulfamerazine suppressed coacervation by 10-15% but it had no significant effect on microglobule size. The extraction of medicated microglobules in various media demonstrated the existence of a porous matrix that required hydration to facilitate extraction of the microglobular drug. Fifteen percent of the encapsulated sulfamerazine was extracted from 25-micron microglobules as opposed to 9% from 10-micron microglobules after equilibration for 24 h in replacement electrolyte solution.
D002214:Capsules; D002626:Chemistry, Pharmaceutical; D005780:Gelatin; D006863:Hydrogen-Ion Concentration; D010368:Pectins; D012996:Solutions; D013416:Sulfamerazine / Q000008:administration & dosage; D013535:Suspensions
D002214:Capsules; D012996:Solutions; D013535:Suspensions; D010368:Pectins; D005780:Gelatin; D013416:Sulfamerazine