Aims: Conventional chitosan nanoparticles (CSNPs) exhibit high encapsulation efficiency for hydrophilic drugs but lack substantial payload capacity for lipophilic drugs. This study explores fabrication of a novel lipid/chitosan nanocomposite suitable for combination therapy using hydrophilic and lipophilic drugs. Methodology: Lipid coating of prefabricated CSNPs that were prepared by ionotropic gelation with tripolyphosphate (TPP) was accomplished in 0.1 M acetate buffer, pH 5.3, using an equimolar mixture of 1, 2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and L-α-dipalmitoylphosphatidyl glycerol (DPPG) or DPPC only. Dynamic laser light scattering (DLS) was used to monitor particle size distribution and zeta potential. Results: Rapid addition of TPP to chitosan (CS) solution prepared in acetate buffer at a final TPP/CS = 0.3:1 (g/g) reproducibly resulted in CSNPs with a mean hydrodynamic diameter of 82.8±1.7 nm and a zeta potential of +20.5±1.2 mV. Hydration of dried phospholipid films using this CSNP suspension progressively increased mean particle size of colloids up to 613.5±13 nm depending on lipid composition and lipid concentration applied. Zeta potential of DPPC/CS nanocomposites was significantly reduced to +8.7±0.1 mV, whereas surface charge of (DPPC/DPPG, 50:50)/CS nanocomposites remained unchanged between +18.8 and +21.6 mV, respectively. Conclusion: Physicochemical assessment of lipid/CS nanocomposites prepared by thin film hydration suggests successful surface immobilization of zwitterionic DPPC on prefabricated CSNPs. The presence of this additional lipid layer surrounding the hydrophilic CS core is predicted to facilitate effective encapsulation of lipophilic drugs enabling combination therapy with hydrophilic and hydrophobic payloads using a single nanodelivery system.

Aims: Conventional chitosan nanoparticles (CSNPs) exhibit high encapsulation efficiency for hydrophilic drugs but lack substantial payload capacity for lipophilic drugs. This study explores fabrication of a novel lipid/chitosan nanocomposite suitable for combination therapy using hydrophilic and lipophilic drugs. Methodology: Lipid coating of prefabricated CSNPs that were prepared by ionotropic gelation with tripolyphosphate (TPP) was accomplished in 0.1 M acetate buffer, pH 5.3, using an equimolar mixture of 1, 2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and L-α-dipalmitoylphosphatidyl glycerol (DPPG) or DPPC only. Dynamic laser light scattering (DLS) was used to monitor particle size distribution and zeta potential. Results: Rapid addition of TPP to chitosan (CS) solution prepared in acetate buffer at a final TPP/CS = 0.3:1 (g/g) reproducibly resulted in CSNPs with a mean hydrodynamic diameter of 82.8±1.7 nm and a zeta potential of +20.5±1.2 mV. Hydration of dried phospholipid films using this CSNP suspension progressively increased mean particle size of colloids up to 613.5±13 nm depending on lipid composition and lipid concentration applied. Zeta potential of DPPC/CS nanocomposites was significantly reduced to +8.7±0.1 mV, whereas surface charge of (DPPC/DPPG, 50:50)/CS nanocomposites remained unchanged between +18.8 and +21.6 mV, respectively. Conclusion: Physicochemical assessment of lipid/CS nanocomposites prepared by thin film hydration suggests successful surface immobilization of zwitterionic DPPC on prefabricated CSNPs. The presence of this additional lipid layer surrounding the hydrophilic CS core is predicted to facilitate effective encapsulation of lipophilic drugs enabling combination therapy with hydrophilic and hydrophobic payloads using a single nanodelivery system.

In a novel attempt, nalidixic acid was formulated in different topical 1%(w/w) gel and cream bases. The viscosity, pH and drug content of preparations were investigated. The highest in vitro release was achieved by (Na-CMC) gel base. The presence of isopropanol as a cosolvent and nalidixic acid sodium benzoate solid dispersion (1: 8) in the selected formulae had enhanced both the in vitro release and antibacterial activity of nalidixic acid. Both DSC and FTIR spectroscopy had shown that the drug is compatible with selected excepients. All cream formulations had shown weaker antibacterial activity therefore only gel bases were further investigated for their stability. No significant change in pH or drug content had been observed in stored gel formulations. The best clinical result in impetigo was achieved after 4-7 days with treatment by gel containing isopropanol and nalidixic acid sodium benzoate solid dispersion (1:8).

In a novel attempt, nalidixic acid was formulated in different topical 1%(w/w) gel and cream bases. The viscosity, pH and drug content of preparations were investigated. The highest in vitro release was achieved by (Na-CMC) gel base. The presence of isopropanol as a cosolvent and nalidixic acid sodium benzoate solid dispersion (1: 8) in the selected formulae had enhanced both the in vitro release and antibacterial activity of nalidixic acid. Both DSC and FTIR spectroscopy had shown that the drug is compatible with selected excepients. All cream formulations had shown weaker antibacterial activity therefore only gel bases were further investigated for their stability. No significant change in pH or drug content had been observed in stored gel formulations. The best clinical result in impetigo was achieved after 4-7 days with treatment by gel containing isopropanol and nalidixic acid sodium benzoate solid dispersion (1:8).

In a novel attempt, nalidixic acid was formulated in different topical 1%(w/w) gel and cream bases. The viscosity, pH and drug content of preparations were investigated. The highest in vitro release was achieved by (Na-CMC) gel base. The presence of isopropanol as a cosolvent and nalidixic acid sodium benzoate solid dispersion (1: 8) in the selected formulae had enhanced both the in vitro release and antibacterial activity of nalidixic acid. Both DSC and FTIR spectroscopy had shown that the drug is compatible with selected excepients. All cream formulations had shown weaker antibacterial activity therefore only gel bases were further investigated for their stability. No significant change in pH or drug content had been observed in stored gel formulations. The best clinical result in impetigo was achieved after 4-7 days with treatment by gel containing isopropanol and nalidixic acid sodium benzoate solid dispersion (1:8).

In a novel attempt, nalidixic acid was formulated in different topical 1%(w/w) gel and cream bases. The viscosity, pH and drug content of preparations were investigated. The highest in vitro release was achieved by (Na-CMC) gel base. The presence of isopropanol as a cosolvent and nalidixic acid sodium benzoate solid dispersion (1: 8) in the selected formulae had enhanced both the in vitro release and antibacterial activity of nalidixic acid. Both DSC and FTIR spectroscopy had shown that the drug is compatible with selected excepients. All cream formulations had shown weaker antibacterial activity therefore only gel bases were further investigated for their stability. No significant change in pH or drug content had been observed in stored gel formulations. The best clinical result in impetigo was achieved after 4-7 days with treatment by gel containing isopropanol and nalidixic acid sodium benzoate solid dispersion (1:8).

In a novel attempt, nalidixic acid was formulated in different topical 1%(w/w) gel and cream bases. The viscosity, pH and drug content of preparations were investigated. The highest in vitro release was achieved by (Na-CMC) gel base. The presence of isopropanol as a cosolvent and nalidixic acid sodium benzoate solid dispersion (1: 8) in the selected formulae had enhanced both the in vitro release and antibacterial activity of nalidixic acid. Both DSC and FTIR spectroscopy had shown that the drug is compatible with selected excepients. All cream formulations had shown weaker antibacterial activity therefore only gel bases were further investigated for their stability. No significant change in pH or drug content had been observed in stored gel formulations. The best clinical result in impetigo was achieved after 4-7 days with treatment by gel containing isopropanol and nalidixic acid sodium benzoate solid dispersion (1:8).

Objective: To enhance 5-fluorouracil (5-FU) permeability through the skin by loading onto gold nanoparticles (GNPs) capped with two cationic ligands, benzalkonium chloride (BC) or poly (ethylene imine) (PEI). Whereas 5-FU has excellent efficacy against many cancers, its poor permeability through biological membranes and several adverse effects limit its clinical benefits. BC and PEI were selected to stabilize GNPs and to load 5-FU through ionic interactions. Methods: 5-FU/BC-GNPs and 5-FU/PEI-GNPs were prepared at different 5-FU/ligand molar ratios and different pH values and were evaluated using different techniques. GNPs stability was tested as a function of salt concentration and storage time. 5-FU release from BC- and PEI-GNPs was evaluated as a function of solution pH. Ex vivo permeability studies of different 5-FU preparations were carried out using mice skin. Results: 5-FU-loaded GNPs size and surface charge were dependent on the 5-FU/ligand molar ratios. 5-FU entrapment efficiency and loading capacity were dependent on the used ligand, 5-FU/ligand molar ratio and solution pH. Maximum drug entrapment efficiency of 59.0 ± 1.7% and 46.0 ± 1.1% were obtained for 5-FU/BC-GNPs and 5-FU/PEI-GNPs, respectively. 5-FU-loaded GNPs had good stability against salinity and after storage for 4 months at room temperature and at 4°C. In vitro 5-FU release was pH- and ligand-dependent where slower release was observed at higher pH and for 5-FU/BC-GNPs. 5-FU permeability through mice skin was significantly higher for drug-loaded GNPs compared with drug-ligand complex or drug aqueous solution. Conclusion: Based on these results, BC- and PEI-GNPs might find applications as effective topical delivery systems of 5-FU.

Objective: To enhance 5-fluorouracil (5-FU) permeability through the skin by loading onto gold nanoparticles (GNPs) capped with two cationic ligands, benzalkonium chloride (BC) or poly (ethylene imine) (PEI). Whereas 5-FU has excellent efficacy against many cancers, its poor permeability through biological membranes and several adverse effects limit its clinical benefits. BC and PEI were selected to stabilize GNPs and to load 5-FU through ionic interactions. Methods: 5-FU/BC-GNPs and 5-FU/PEI-GNPs were prepared at different 5-FU/ligand molar ratios and different pH values and were evaluated using different techniques. GNPs stability was tested as a function of salt concentration and storage time. 5-FU release from BC- and PEI-GNPs was evaluated as a function of solution pH. Ex vivo permeability studies of different 5-FU preparations were carried out using mice skin. Results: 5-FU-loaded GNPs size and surface charge were dependent on the 5-FU/ligand molar ratios. 5-FU entrapment efficiency and loading capacity were dependent on the used ligand, 5-FU/ligand molar ratio and solution pH. Maximum drug entrapment efficiency of 59.0 ± 1.7% and 46.0 ± 1.1% were obtained for 5-FU/BC-GNPs and 5-FU/PEI-GNPs, respectively. 5-FU-loaded GNPs had good stability against salinity and after storage for 4 months at room temperature and at 4°C. In vitro 5-FU release was pH- and ligand-dependent where slower release was observed at higher pH and for 5-FU/BC-GNPs. 5-FU permeability through mice skin was significantly higher for drug-loaded GNPs compared with drug-ligand complex or drug aqueous solution. Conclusion: Based on these results, BC- and PEI-GNPs might find applications as effective topical delivery systems of 5-FU.

Objective: To enhance 5-fluorouracil (5-FU) permeability through the skin by loading onto gold nanoparticles (GNPs) capped with two cationic ligands, benzalkonium chloride (BC) or poly (ethylene imine) (PEI). Whereas 5-FU has excellent efficacy against many cancers, its poor permeability through biological membranes and several adverse effects limit its clinical benefits. BC and PEI were selected to stabilize GNPs and to load 5-FU through ionic interactions. Methods: 5-FU/BC-GNPs and 5-FU/PEI-GNPs were prepared at different 5-FU/ligand molar ratios and different pH values and were evaluated using different techniques. GNPs stability was tested as a function of salt concentration and storage time. 5-FU release from BC- and PEI-GNPs was evaluated as a function of solution pH. Ex vivo permeability studies of different 5-FU preparations were carried out using mice skin. Results: 5-FU-loaded GNPs size and surface charge were dependent on the 5-FU/ligand molar ratios. 5-FU entrapment efficiency and loading capacity were dependent on the used ligand, 5-FU/ligand molar ratio and solution pH. Maximum drug entrapment efficiency of 59.0 ± 1.7% and 46.0 ± 1.1% were obtained for 5-FU/BC-GNPs and 5-FU/PEI-GNPs, respectively. 5-FU-loaded GNPs had good stability against salinity and after storage for 4 months at room temperature and at 4°C. In vitro 5-FU release was pH- and ligand-dependent where slower release was observed at higher pH and for 5-FU/BC-GNPs. 5-FU permeability through mice skin was significantly higher for drug-loaded GNPs compared with drug-ligand complex or drug aqueous solution. Conclusion: Based on these results, BC- and PEI-GNPs might find applications as effective topical delivery systems of 5-FU.