Synthesis of pseudoboehmite from NaOH and AlCl3.6H2O for controlled release of drugs

Abstract

The sol-gel obtained pseudoboehmite is an aluminum compound [AlOOH].xH2O, a non-metallic synthetic inorganic nanomaterial with high purity and high specific surface area. Studies are currently being held to use it in the controlled release of drugs. Drugs of controlled delivery aim at offering a therapeutically dosage to a predetermined place in the body, keeping a desired drug concentration, thus controlling the speed release and how long it is retained in the body. The present work seeks to obtain pseudoboehmite as support to the controlled release of Acyclovir. The pseudoboehmite nanoparticles were obtained through sol-gel process using aluminum chloride hexahydrate in sodium chloride and sodium hydroxide solution. A 3.00 OH/Al molar ratio was kept and synthesis with a 0.4 and 0.5 [OH]- molar concentration at 20°C and 65°C were carried. The aging effect at 95°C/120h was also analyzed. For the Acyclovir in vitro analysis in the gastric medium, the acyclovir dissolution with pseudoboehmite was realized in a HCl 0,1 mol/L. For the in vitro analysis in plasmatic absorption, in the intestinal system, the release of Acyclovir in distilled water was analyzed. Pseudoboehmite showed a structure with high specific surface area, which remained stable in both environments used to emulate the Acyclovir liberation. The results made evident that the pseudoboehmite used as excipient to the controlled release of Acyclovir kept the drug’s chemical stability, without degrading it or the pseudoboehmite. The Acyclovir concentration curves shows that pseudoboehmite synthesis with low temperatures and not aged results in more uniform dissolution rates, a desired characteristic in the drug release. The experiments shows that there is also a correlation between these synthesis conditions and the pseudoboehmite superficial area and porosity.