Formulation and characterization of chloramphenicol gelatin microspheres

Chloramphenicol loaded gelatin microspheres, as a specific oral drug delivery system, were prepared by two different methods. The effects of drug payload, and cross-linking with formaldehyde at different concentration levels on the size of microspheres and drug release from microspheres were studied. The results revealed that by increasing the drug payload, the diameter of microspheres was increased and also a faster drug release rate was obtained. However, the amounts of drug released were decreased. The kinetics of drug release from gelatin microspheres were found to conform with the Higuchi diffusion model. The results of in vivo studies in human volunteers showed that the peak urinary excretion of chloramphenicol gelatin microspheres occurred at 9 hours post-dosing and sustained over a period of 9 to 30 hours as compared with the control [7 hours]. So, the objectives of this study were achieved through improving both bioavailability of chloramphenicol. In addition, the frequency of administration and undesired systemic side effects were also reduced

Preparation and characterization of chloramphenicol starch microspheres

Soluble starch microspheres containing chloramphenicol were prepared by interfacial cross-linking technique using terephthaloyl chloride. The effects of various emulsification conditions such as initial drug loading, pH of the aqueous phase, speed of agitation and concentration of cross-linking agent on the characteristics of microspheres were investigated. For comparison, commercial Sephadex microspheres containing chloramphenicol were also prepared by lyophilization. The in vitro release studies indicated that soluble starch microspheres caused chloramphenicol release profiles to be sustained longer than those prepared with Sephadex. The degradation behavior, hydrophilic and bioadhesive properties of the formulated chloramphenicol microspheres were compared with gelatin and albumin microspheres previously prepared in the laboratories. Sephadex microspheres exhibited the highest hydrophilic property, while albumin microspheres showed the best bioadhesive behavior when compared with other tested microspheres. On the other h and, polysaccharides microspheres had a certain resistance to digested by pancreatin and pepsin enzymes solutions. The release kinetics of chloramphenicol from polysaccharides microspheres was found to conform with Higuchi model