title: Development of a nanoprecipitation method for the entrapment of a very water soluble drug into Eudragit RL nanoparticles.
abstract: Rivastigmine hydrogen tartrate (RHT), one of the potential cholinesterase inhibitors, has received great attention as a new drug candidate for the treatment of Alzheimer's disease. However, the bioavailability of RHT from the conventional pharmaceutical forms is low because of the presence of the blood brain barrier. The main aim of the present study was to prepare positively charged Eudragit RL 100 nanoparticles as a model scaffold for providing a sustained release profile for RHT. The formulations were evaluated in terms of particle size, zeta potential, surface morphology, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Drug entrapment efficiency andin vitrorelease properties of lyophilized nanoparticles were also examined. The resulting formulations were found to be in the size range of 118 nm to 154 nm and zeta potential was positive (+22.5 to 30 mV). Nanoparticles showed the entrapment efficiency from 38.40 ± 8.94 to 62.00 ± 2.78%. An increase in the mean particle size and the entrapment efficiency was observed with an increase in the amount of polymer. The FTIR, XRD, and DSC results ruled out any chemical interaction between the drug and Eudragit RL100 polymer. RHT nanoparticles containing low ratio of polymer to drug (4:1) presented a faster drug release and on the contrary, nanoparticles containing high ratio of polymer to drug (10:1) were able to give a more sustained release of the drug. The study revealed that RHT nanoparticles were capable of releasing the drug in a prolonged period of time and increasing the drug bioavailability.
authors.affiliation: Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Science, Tabriz, I.R. Iran; Student Research Committee, Tabriz University of Medical Science, Tabriz, I.R. Iran.
authors.forename: Sara
authors.initials: S
authors.lastname: Salatin
authors.affiliation: Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Science, Tabriz, I.R. Iran; Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, I.R. Iran.
authors.forename: Jaleh
authors.initials: J
authors.lastname: Barar
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, I.R. Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Barzegar-Jalali
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, I.R. Iran; Drug Applied Research Center and Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, I.R. Iran.
authors.forename: Khosro
authors.initials: K
authors.lastname: Adibkia
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, I.R. Iran; Zahravi pharmaceutical company, Tabriz, I.R. Iran.
authors.forename: Farhad
authors.initials: F
authors.lastname: Kiafar
authors.affiliation: Department of Pharmaceutics, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, I.R. Iran; Drug Applied Research Center and Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, I.R. Iran.
authors.forename: Mitra
authors.initials: M
authors.lastname: Jelvehgari
keywords: Eudragit RL100; Nanoparticles; Nanoprecipitation; Rivastigmine hydrogen tartrate