Development of Oral Sustained Release Rifampicin Loaded Chitosan Nanoparticles by Design of Experiment

Objective. The main objective of the present investigation was to develop and optimize oral sustained release Chitosan nanoparticles (CNs) of rifampicin by design of experiment (DOE). Methodology. CNs were prepared by modified emulsion ionic gelation technique. Here, inclusion of hydrophobic drug moiety in the hydrophilic matrix of polymer is applied for rifampicin delivery using CN. The 23 full-factorial design was employed by selecting the independent variables such as Chitosan concentration ( ), concentration of tripolyphosphate ( ), and homogenization speed ( ) in order to achieve desired particle size with maximum percent entrapment efficiency and drug loading. The design was validated by checkpoint analysis, and formulation was optimized using the desirability function. Results. Particle size, drug entrapment efficiency, and drug loading for the optimized batch were found to be 221.9？nm, 44.17 ± 1.98% W/W, and 42.96 ± 2.91% W/W, respectively. In vitro release data of optimized formulation showed an initial burst followed by slow sustained drug release. Kinetic drug release from CNs was best fitted to Higuchi model. Conclusion. Design of Experiment is an important tool for obtaining desired characteristics of rifampicin loaded CNs. In vitro study suggests that oral sustained release CNs might be an effective drug delivery system for tuberculosis. 1. Introduction In spite of the absolute number of incident TB cases falling globally, tuberculosis (TB) continues to be the leading cause of mortality worldwide and has also been considered to be an occupational disease in the health care setup [1]. One of the major problems in the current treatment of tuberculosis is the noncompliance to prescribed regimens, primarily because treatment of TB involves continuous, frequent multiple drug dosing. Adherence to treatment and the outcome of therapy could be improved with the introduction of long-duration drug formulations releasing the antitubercular agents in a slow and sustained manner [2]. Polymer-based drug delivery systems like polymeric nanoparticles have achieved a potential position in the controlled release of therapeutic agents [3]. Polymeric nanoparticles are solid colloidal particles with diameters ranging from 1 to 1000？nm [4]. They consist of macromolecular materials in which the active ingredient is dissolved, entrapped, encapsulated, and adsorbed or chemically attached. The fate of nanoparticles in the gastrointestinal tract has extensively been investigated [5–7]. Sustained release cross-linked polymeric nanoparticles enable improvement of drug