Purpose Adefovir dipivoxil (AD), a nucleoside reverse transcriptase inhibitor is effective against Hepatitis B virus. Its poor oral bioavailability leads to frequent administration causing severe adverse effects. Thereby the entrapment of AD within lipid nanoparticulate systems is a way of increasing AD oral bioavailability as a result of improving intestinal permeability with efficient liver-targeted delivery together with higher drug stability during storage. Methods AD-loaded nanostructured lipid carriers (AD-NLCs) were prepared via solvent emulsification diffusion technique adopting 2 4 full factorial design to study the effect of lipid percentage, presence of egg yolk lecithin, surfactant type and percentage on entrapment efficiency (E.E.%), particle size and percent in-vitro drug released after 8 h (Q8hrs). Results Formula (F12) showed E.E.% of 90.5 ± 0.2%, vesicle size of 240.2 ± 2.5 nm and Q8hrs of 58.55 ± 9.4% was selected as the optimum formula with desirability value of 0.757 based on highest EE%, lowest P.S. and Q8hrs. Further evaluation of the optimized formula using radioiodinated rose bengal (RIRB) in thioacetamide induced liver damage in Swiss Albino mice revealed a higher liver uptake of 22 ± 0.01% ID/g (percent injected dose/g organ) and liver uptake/Blood (T/B) ratio of 2.22 ± 0.067 post 2 h of I.V injection of RIRB compared to 9 ± 0.01% ID/g and 0.64 ± 0.017 in untreated group, respectively. Conclusion NLCs could be successfully used as oral drug delivery carriers of the antiviral drug Adefovir Dipivoxil to the liver with higher stability and oral bioavailability.

The research objective is to design intranasal (IN) brain targeted CLZ-loaded polymeric nanomicellar systems (PNMS) aiming to improve central systemic CLZ bioavailability. Direct equilibrium method was used to prepare CLZ-PNMS using two hydrophobic poloxamines; Tetronic V R 904 (T904) and Tetronic V R 701 (T701) and one hydrophilic poloxamer; Synperonic V R PE/F127 (F127). Optimization is based on higher percent transmittance, solubilizing efficiency, and in vitro release after 24 h with smaller particle size was achieved using Design-Expert V R software. The optimized formula was further evaluated via TEM, ex vivo nasal permeation in addition to in vivo biodistribution using radiolabeling technique of the optimized formula by Technetium-99m ( 99m Tc). The optimized formula M5 has small size (217 nm) with relative high percentage of transmittance (97.72%) and high solubilization efficacy of 60.15-fold following 92.79% of CLZ released after 24 h. Ex vivo nasal permeation showed higher flux of 36.62 lg/ cm 2 .h compared to 7.324 lg/cm 2 .h for CLZ suspension with no histological irritation. In vivo biodistribution results showed higher values of radioactivity percentage of the labeled optimized formula ( 99m Tc-M5) in brain and brain/blood ratio following IN administration of 99m Tc-M5 complex which were greater than their corresponding values following intravenous route. It is obvious that nasal delivery of CLZ-PNMS could be a promising way to improve central systemic CLZ bioavailability.

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Scandium-47 is one of the most useful radioisotopes which is gaining great importance in cancer theranostics applications due to its favorable nuclear and chemical properties. MCNPX2.7.0 code was used to simulate the neutron activation of natural calcium target positioned at a thermal neutron flux of 1.8 × 1014 n cm−2 s−1 in the Egypt Second Research Reactor (ETRR-2). The burn card was used to calculate 47Ca and 47Sc radioactivities during 3 days irradiation and 20 days post-irradiation. The undesirable impurities generated during this period were also calculated. The obtained calculations were found to be in agreement with the experimental measurements. The distribution coefficient value (Kd) of 47Sc(III) as well as 47Ca(II) ions was determined using the commercially available ion-exchanger Chelex 100 in HNO3 and/or HCl media. Radiochemical separation of 47Sc(III) from 47Ca(II) was studied using HNO3 and HCl solutions and the results showed that HNO3 is a better medium than HCl for complete retention and recovery of 47Sc(III), where the recovery yields were 85 ± 1.2 and 95 ± 0.87 % using 1 M HCl and 1 M HNO3 solutions, respectively. The recovery yield obtained in our work was higher than in the reported procedures. Radionuclidic, radiochemical and chemical purities were investigated to ensure the suitability of 47Sc(III) for nuclear medicine applications.

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