Title:Poloxamer based Urapidil Loaded Chitosan Microparticle in Approach to
Improve the Mechanical Strength by Tensile Strength and Entrapment
Determination
Volume: 17
Issue: 1
Author(s): Harekrishna Roy, Bhabani Shankar Nayak and Sisir Nandi*
Affiliation:
- Department of Pharmaceutical Chemistry, Global
Institute of Pharmaceutical Education and Research, Kashipur, 244713, India
Keywords:
Mechanical strength, chitosan microparticle, poloxamer-188, texture analyzer, microparticles, entrapment efficiency, chitosan-based hydrogels.
Abstract:
Background: The literature review has highlighted the issues related to the poor mechanical
strength of chitosan-based microparticles. In an attempt to resolve the drawbacks, the microparticles
were prepared with a suitable combination of poloxamer-188 (pluronic) and chitosan-based hydrogels.
Objective: The current study dealt with urapidil-loaded chitosan microparticles incorporating chitosanbased
hydrogels and small polyanionic electrolytes. The mechanical strength was ascertained by entrapment
efficiency and texture analyzer.
Methods: Chitosan-based hydrogels and the combination of poloxamer and further microparticles
were prepared by the counter-ion aggregation technique in a polyanionic electrolyte medium (20 %
w/v). During the preparation, poloxamer was incorporated to improve the mechanical strength, which
was ascertained in terms of adhesive strength (tensile strength) by texture analyzer and entrapment efficiency.
The prepared microparticles were also subjected to micrometric studies, swelling index, surface
morphology study, drug-polymer interaction study, and zeta analysis.
Results: A remarkable increase in entrapment efficiency (maximum of 78.56 % from SSP4) was observed
with the progressive increase in poloxamer-188. In addition to that, the adhesive strength was
also studied by a texture analyzer for all microparticles. Sodium citrate-based products exhibited superior
adhesive strength values than sodium sulfate- and sodium tripolyphosphate-based products, indicating
the significance of incorporating poloxamer-188. A significant finding was also recorded for the
swelling properties at microenvironmental pH attributed to polyanions. It was observed that sodium
TPP microparticles continued to swell in a phosphate buffer of pH 6.8. Zeta value was found to be
maximum with -5.2 mV; however, it could further be improved by adding electrolytes. TPP4 showed a
comparatively larger particle size of 8.07 μm. Polydispersity index value revealed homogenous dispersion
of microparticles. SEM study revealed prominent porous surfaces for sodium tripolyphosphate
microparticles.
Conclusion: The study revealed that the addition of poloxamer-188 improved the mechanical
strength, identified by entrapment efficiency and texture analysis. SCP4 microparticle was found to be
the best formulation among all.
