Nanoscience and Molecular Nanotechnology

Biography

Biography: Mazita Mohd Diah

Abstract

Nanoparticulate drug delivery systems refer to systems in which drugs are physically incorporated into nanoparticles or nano entities. Nanoparticles, being small with a large specific surface area, increase solubility, enhance bioavailability, improve controlled release and enable precision targeting of the entrapped compounds. In this study, carboxymethyl-oligochitosan (CMoligochitosan) as polymeric permeation enhancer was conjugated to a polar pro-drug, carboxymethyl-5-fluorouracil (CMFU) through succinate linker, to increase the skin drug permeation. CM-oligochitosan-CMFU conjugate was then transformed into nanoparticles (NP) via spray drying technique. Skin drug permeation was profiled through treating the Sprague Dawley rat’s skin (in vitro) with CM-oligochitosan-CMFU NP and CMFU and, had the skin characterized using ATR-Fourier transform infra-red (ATRFTIR)
spectroscopy, differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) techniques. The nanoparticles were characterized by particle size: 229.10±57.05 nm, polydispersity index: 0.60±0.15, zeta potential: -55.92±24.48 mV and drug content: 2.29±0.27% w/w. The level of skin drug permeation of CM-oligochitosan-CMFU NP was higher than CMFU, which had no conjugation to CM-chitosan and nanoparticulation, following 24 hours of study. ATR-FTIR spectra of the untreated skin showed characteristic CH stretching vibrational peaks (asymmetric and symmetric CH2) associated with the lipid alkyl chains of epidermis at 2918.63±0.02 and 2850.56±0.15 cm-1. Similar peaks were not obtainable in skin samples treated with CM-oligochitosan-CMFU NP, while CH peak of lipid was noted in epidermis treated with CMFU. The interaction of CM-oligochitosan-CMFU NP with CH
regime of epidermis could have disrupted and loosened the lipid packing thus facilitating skin drug permeation. Through treating the skin with CM-oligochitosan-CMFU NP, the amide I band of skin was shifted to lower wavelength from 1646.83±1.08 cm-1 to 1642.40±3.72 cm-1 unlike cases of CMFU. The band shift indicated that corneocytes perhaps dehydrated and shrunk, thereby leading to the formation of larger intercellular aqueous pores and better nanoparticles permeation. The ATR-FTIR outcome was furthersupported by thermal and morphological analysis. DSC analysis showed that the melting temperature and enthalpy of endotherm at 65.92±0.570C related to lamellar lipid structure were reduced when the skin was treated with CM-oligochitosan-CMFU NP. The skin lipid packing became disordered and this was not observable in study using CMFU. Using SEM, the skin treated with CMoligochitosan-CMFU NP was characterized with pore formation, while the surfaces of skin remained intact when it was treated with CMFU.