Controlled release of Capreomycin sulfate from pHresponsive nanocapsules

Abstract

The synthesis of polymeric nanocapsules loaded with the antituberculosis drug Capreomycin sulphate is presented in this work. The pHresponsive polymeric nanocapsules were successfully synthesized using the RAFT-based vesicle templating approach in the presence of Capreomycin sulphate. Anionic small polyelectrolytes comprising randomly distributed butyl acrylate and acrylic acid units were adsorbed on cationic vesicles of dimethyldioctadecyl ammonium bromide (DODAB). N,N-(dimethylamino)ethyl methacrylate (DMAEMA) and methyl methacrylate (MMA) or tertiary butyl methacrylate (tBMA) and MMA were used for the formation of the polymeric shells. Subsequently the tBMA was hydrolyzed to obtain negatively charged nanocapsules. The nanocapsule morphology for both approaches was characterized by DLS and TEM. The most stable hollow latex particles were obtained with the monomer composition of DMAEMA:MMA = 1:1. These nanocapsules were found to be colloidally stable and pH-responsive. The entrapment efficiency of drug determined by UV-Vis-spectroscopy was 70 %. The drug release rate from nanocapsules at pH 6.5 was found to be relatively fast (substantial release within one hour already), however we believe slower release can be achieved by using a thicker polymer shell.

Polymeric Nanocapsules as Nanotechnological Alternative for Drug Delivery System: Current Status, Challenges and Opportunities

“…For example, pH sensitive polymeric nanocapsules were formulated by using RAFT/emulsion polymerization. A random copolymer consisting of butyl acrylate and acrylic acid was pre-synthesized as macroRAFT agent [ 105 , 106 ]. N,N-(dimethylamino)ethyl methacrylate or tertiary butyl methacrylate with methyl methacrylate were used to preform nanocapsules.…”

Synthesis and Comparative Study of Nanoparticles Derived from Bovine and Human Serum Albumins

“…Commonly, glutaraldehyde is used as a cross-linking agent [22][23][24][25][26][27][28]. Previously with the glutaraldehyde we prepared the albumin nanoparticles with a size of 182 ± 8 nm and a polydispersity of 0.14; then such particles have been loaded with various antitumor drugs [29].…”

Morphology Control of Liposome - RAFT Oligomer Precursors to Complex Polymer Nanostructures

“…This so-called RAFT oligomer contained hydrophobic butyl acrylate (BA) and hydrophilic, anionic acrylic acid (AA) units, which could ″attach″ to the cationic dimethyldioctadecylammonium bromide (DODAB) vesicle surface. These RAFT oligomers were then chain-extended to achieve the desired shell thickness. − This process was found to result in several different final morphologies, including capsules, protruded capsules, parachute-like, and necklace-like structures. − In previous work, where we studied the effect of cross-linking during the chain extension step, we found that a significant part of the capsules showed protrusions, with about 20% of the capsules showing a protrusion when we did not use any cross-linker . This result suggested that the final morphology may actually be ″predefined″ by the morphology of the oligomer-vesicle precursors, and the fact that the oligomers have a molar mass and chemical composition distribution makes it very conceivable that indeed different morphologies of the oligomer-vesicle precursors exist …”