A new lipid-based oral delivery system of erythromycin for prolong sustain release activity

Erythromycin-loaded solid lipid microparticles (SLM) based on solidified reverse micellar solution (SRMS) as an oral delivery formulation was studied. Hot homogenization technique was employed to prepare erythromycin stearate-loaded SLMs using blends of Softisan (R) 154 and Phospholipon (R) 90H or beeswax in the ratio of 1:2, and characterized in vitro. Antibacterial evaluation of the formulations was carried out by agar diffusion technique against some selected clinical isolates of bacterial. Preliminary pharmacokinetic study was performed after oral administration in male Albino rats. The results of matrix contain Softisa (R) 154 and phospholipon (R) 90H (1:2) showed that erythromycin-loaded SLM was smooth; particle size ranged from 10.3 +/- 11.24 pm to 18.1 +/- 10.11 pm and maximum encapsulation efficiency and loading capacity were 95.11 +/- 0.3% and 43.22 +/- 0.1 mg, respectively. While that of beeswax-containing matrix showed maximum particle size of 18.9 +/- 21.10 pm, maximum encapsulation efficiency of 89.01 +/- 0.11% and loading capacity of 39.02 +/- 0.12 mg. All the formulations had prolonged release and antibacterial activity. Significantly (p > 0.05), prolonged plasma erythromycin concentration was obtained in the optimized formulation (> 14 h) compared with commercial sample of erythromycin tablet (10h). Erythromycin stearate-loaded SLMs formulation could serve as an alternative to conventional oral formulation of erythromycin.