Nanoemulsions — Advances in Formulation, Characterization and Applications in Drug Delivery | InTechOpen, Published on: 2014-07-25. Authors: S.A. Chime, F.C. Kenechukwu and A.A. Attama

Objective: To formulate and evaluate solid-reversed-micellar-solution (SRMS)-based solid lipid microparticles (SLMs) for intramuscular administration of gentamicin. Methods: SRMS formulated with Phospholipon® 90G and Softisan® 154 were used to prepare gentamicin-loaded SLMs. Characterizations based on size and morphology, stability and encapsulation efficiency (EE%) were carried out on the SLMs. In vitro release of gentamicin from the SLMs was performed in phosphate buffer while in vivo release studies were conducted in rats. Results: Maximum EE% of 90.0, 91.6 and 83.0% were obtained for SLMs formed with SRMS 1:1, 1:2 and 2:1, respectively. Stable, spherical and smooth SLMs of size range 9.80 ± 1.46 µm to 33.30 ± 6.42 µm were produced. The release of gentamicin in phosphate buffer varied widely with the lipid contents. Moreover, significant (p < 0.05) amount of gentamicin was released in vivo from the SLMs. Conclusion: SRMS-based SLMs would likely offer a reliable means of delivering gentamicin intramuscularly.

Oral delivery of insulin provides a good alternative because it is non-invasive and patient-friendly. However, multiple challenges affected this route. To overcome barriers for oral delivery of insulin, we aimed to develop a novel insulin-loaded microemulsion system based on snail mucin for oral administration. The strategy in the novel system of using mucin loading insulin into the inner core of prepared water in oil microemulsion to provide sustained released, increased in vivo stability and enhanced drug absorption in the gastrointestinal tract. We report how microemulsion composed of varying ratios of snail mucin and Tween® 80 (1:9-9:1) using oil/water emulsion preparation method influenced insulin performance after oral administration. The results obtained include an encapsulation efficiency of above 70 %; in vitro release was sustained over 10 h and in vivo evaluations in diabetic rat model shows that insulin-loaded microencapsulation effectively reduced blood glucose levels over a period >8 h after oral administration. Therefore, we suggest that the developed formulation for oral insulin can be a promising alternative dosage form for oral protein delivery.