Effect of PEG2000 on drug delivery characterization from solid lipid nanoparticles

The purpose of this work is to develop a PEG2000-modified solid lipid nanoparticles (SLN) intended to encapsulate a drug within their matrix and to study their characteristics. In the present report, drug-loaded SLN were prepared by a novel solvent diffusion method in an aqueous system. Monostearin and PEG2000 were used as carrier material and modifying agent, respectively. The model drug salbutamol sulphate was incorporated to study the characterization of entrapment efficiency, size, zeta potential (charge) and drug delivery characterization. In the test solution of pH 7.2 phosphate buffer, drug-release behavior from SLN suspension exhibited a biphasic pattern. With the monoastearin-based SLN, a distinctly prolonged release over a monitored period of 14 days was observed after a burst drug release in the first 8 hours. Over the monitored period of prolonged release, there was delayed release in the first 5 days with nearly 2.51% of the drug released each day, following which a slightly higher release rate (8.14% per day) appeared in the last 9 days. In contrast, the drug release rate from PEG2000-modified SLN was faster. Nevertheless, further work is required in order to optimize the release behavior of various entrapped drugs. These results also demonstrate that modification with PEG2000 can accelerate release of hydrophilic small molecule drugs from SLN.