Assessment of drug permeation from lipid nanoparticles formulated with a novel structured lipid matrix through artificial skin construct bio-engineered from HDF and HaCaT cell lines

The permeation of three drugs from solid lipid nanoparticles (SLN) was assessed using artificial skin construct (ASC) bio-engineered from human dermal fibroblast (HDF) and keratinocytes of HaCaT cell line (human adult keratinocytes, low calcium condition, elevated temperature). SLN containing diclofenac sodium, timolol hydrogen maleate and hydrocortisone were formulated with a novel structured lipid matrix composed of 1:1 mixture of beeswax and goat fat by melt emulsification with high pressure homogenization and characterized. In vitro release studies and drug permeation studies through ASC were carried out using a modified Franz diffusion cell. Differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD) results showed low crystalline nanoparticles. Particle size analysis indicated very low growth in particle size with time. Zeta potential measurement showed high negative potentials after three months. Encapsulation efficiencies of the SLN batches were high and in vitro release profiles revealed sustained release of all the incorporated drugs in phosphate buffer (pH 7.4). Permeation of the drugs through the ASC was high compared with free drug dispersions. The novel structured lipid matrix containing phospholipid could be used to overcome low drug encapsulation efficiency encountered in SLN. The structured lipid used in this study could be used in preparation of SLN for topical or transdermal delivery.