Solid lipid nanoparticles of diethylcarbamazine citrate for enhanced delivery to the lymphatics: in vitro and in vivo evaluation

Objectives: The major objective is to target diethylcarbamazine citrate (DEC) to the lymphatics and to increase its retention time. The effect of various excipients on the physicochemical characteristics of the nanoparticles was also studied. Materials and methods: Solid lipid nanoparticles (SLNs) of DEC were prepared by ultrasonication by varying the concentrations of compritol 888 ATO, poloxamer 188 and soya lecithin. The SLNs were evaluated for size, shape, texture, surface charge, physical nature of the entrapped drug, entrapment efficiency and in vitro drug release. In vivo animal studies were carried out to estimate the pharmacokinetic parameters in blood and drug concentration in lymph after oral administration. Results: The size of the spherical particles was in the range of 27.25 +/- 3.43 nm to 179 +/- 3.08 nm and a maximum entrapment efficiency of 68.63 +/- 1.53% was observed. In vitro release studies in pH 7.4 PBS displayed a rapid release and the maximum time taken for the complete drug to release was 150 min. In vivo studies indicated an enhancement in the amount of drug that reached lymphatics when administered via SLNs. Conclusion: Targeting of DEC to the lymphatics is possible through SLNs and the retention time in the lymphatics can also be enhanced.