Hybrid Nannoparticles Case Study

The objective of the present work was to formulate, characterize and optimize the preparations of hybrid nanoparticles containing dapsone which is finally converted into gel for topical drug delivery. The formulations were characterized for particle size, zeta potential and entrapment efficiency and were optimized by applying factorial design of experiment (23). The results showed that the optimal formulation (HN 4) of dapsone loaded hybrid nanoparticles had average particle size of 277nm, zeta potential of 26.7 mV, entrapment efficiency of 75.81%, and polydispersity index of 0.502. Transmission electron microscopy (TEM) indicated that hybrid nanoparticles were spherical in shape and polymer core was coated by lipid shell. The stability studies
First step involved preparation of lipidic nanoparticles and second step was the preparation of hybrid particles (coating of lipid nanoparticles over polymer) following ultrasonication which ultimately yielded core shell type lipid polymer hybrid nanoparticles.

Experimental factorial design
Three different variables and their influence over physicochemical properties of hybrid nanoparticles were evaluated using a 23 factorial design composed of 3 variables which were set at 2-levels each. The independent variables were X1: amount of polymer (mg), X2: lipid concentration (%w/w) and X3: emulsifier concentration (%w/w). The established dependent variables were the mean Y1: particle size, Y2: zeta potential and Y3: entrapment efficiency. The experimental design required a total of 9 experiments. The data were analyzed using Design Expert® software (Trial Version 7.1.6, Stat-Ease Inc., MN).
Preparation of Nanostructured Lipid Carriers (NLCs)
Melt-Emulsification and
A weighed amount of solid lipid and liquid oil were blended and melted at 70◦C to form a uniform and clear oil phase. Meanwhile, the aqueous phase consisted of Tween 80, dispersed in distilled water was kept on stirrer at 2000 rpm at same temperature. After that oil phase was slowly added to the hot aqueous phase and stirred for 15 min. The coarse emulsion was further treated by probe-type sonicator for 15 min. Subsequently the dispersion was cooled in ice water bath to room temperature and stored at 4◦C.
Preparation of Hybrid Nanoparticles
Modified nanoprecipitation method
HPMC (polymer) and drug were dissolved in 1:1 mixture of methanol and dichloromethane. The organic polymer solution was then added drop by drop to the prepared NLC dispersion placed on magnetic stirrer at 70 ̊ C. The resultant dispersion was further stirred for 60 minutes at 70 ̊ C. The mixture was then ultrasonicated to reduce the particle size to nanometer range.
CHARACTERIZATION
3.3.1 Particle Size and Size Distribution
To analyze the size and a width of size distribution, dynamic light scattering (DLS) was performed for all the batches using Malvern Zetasizer Nano ZS (Malvern Instruments, UK). The nanoparticles were dispersed in double distilled water (DDW) and the system was set at