The purpose of this research was to prepare acyclovir niosomes in a trial to improve its poor and variable oral bioavailability. The nonionic surfactant vesicles were prepared by the conventional thin film hydration method. The lipid mixture consisted of cholesterol, span 60, and dicetyl phosphate in the molar ratio of 65:60:5, respectively. The percentage entrapment was~11% of acyclovir used in the hydration process. The vesicles have an average size of 0.95 μm, a most probable size of 0.8 μm, and a size range of 0.4 to 2.2 μm. Most of the niosomes have unilamellar spherical shape. In vitro drug release profile was found to follow Higuchi's equation for free and niosomal drug. The niosomal formulation exhibited significantly retarded release compared with free drug. The in vivo study revealed that the niosomal dispersion significantly improved the oral bioavailability of acyclovir in rabbits after a single oral dose of 40 mg kg −1 . The average relative bioavailability of the drug from the niosomal dispersion in relation to the free solution was 2.55 indicating more than 2-fold increase in drug bioavailability. The niosomal dispersion showed significant increase in the mean residence time (MRT) of acyclovir reflecting sustained release characteristics. In conclusion, the niosomal formulation could be a promising delivery system for acyclovir with improved oral bioavailability and prolonged drug release profiles.

A B S T R A C TThe aim of this study was to design a controlled release vehicle for insulin to preserve its stability and biological activity during fabrication and release. A modified, double emulsion, solvent evaporation, technique using homogenisation force optimised entrapment efficiency of insulin into biodegradable nanoparticles (NP) prepared from poly (DL-lactic-co-glycolic acid) (PLGA) and its PEGylated diblock copolymers. Formulation parameters (type of polymer and its concentration, stabiliser concentration and volume of internal aqueous phase) and physicochemical characteristics (size, zeta potential, encapsulation efficiency, in vitro release profiles and in vitro stability) were investigated. In vivo insulin sensitivity was tested by diet-induced type II diabetic mice. Bioactivity of insulin was studied using Swiss TO mice with streptozotocin-induced type I diabetic profile. Insulin-loaded NP were spherical and negatively charged with an average diameter of 200-400 nm. Insulin encapsulation efficiency increased significantly with increasing ratio of co-polymeric PEG. The internal aqueous phase volume had a significant impact on encapsulation efficiency, initial burst release and NP size. Optimised insulin NP formulated from 10% PEG-PLGA retained insulin integrity in vitro, insulin sensitivity in vivo and induced a sustained hypoglycaemic effect from 3 h to 6 days in type I diabetic mice..

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The recorded results highlighted the potential for SMEDDS and niosomes for widening the absorption window of acidic drugs after oral administration.

Aim: Herein, tumor-targeted quantum dots (QDs)-based theranostic nanocapsules (NCs) coloaded with celecoxib and honokiol were developed. Materials & methodology: The anionic CD44-targeting chondroitin sulfate and cationic low density lipoprotein (LDL)-targeting lactoferrin (LF) were sequentially assembled onto the surface of the positively charged oily core. As an imaging probe, highly fluorescent mercaptopropionic acid-capped cadmium telluride QDs were coupled to LF. Results: In vitro, fluorescence of QDs was quenched (OFF state) due to combined electron/energy transfer-mediated processes involving LF. After intracellular uptake of NCs, fluorescence was restored (ON state), thus enabled tracing their internalization. The NCs demonstrated enhanced cytotoxicity against breast cancer cells as well as superior in vivo antitumor efficacy. Conclusion: We propose these multifunctional nanotheranostics for imaging and targeted therapy of breast cancer.