Nanomed. J., 3(4): 253-267, Autumn 2016 253 Optimization, preparation and characterization of rutin-quercetin dual drug loaded keratin nanoparticles for biological applications Selvaraj Kunjiappan 1* ; Anindita Chowdhury 2 ; Balasubramanian Somasundaram 1 ; Chiranjib Bhattacharjee 2 ; Selvam Periyasamy 1 1 Sir CV Raman- KS Krishnan International Research Centre, Kalasalingam University, Krishnankoil, India 2 Department of Chemical Engineering, Jadavpur University, Kolkata, India ABSTRACT Objective(s): Response surface methodology (RSM) by central composite design (CCD) was applied to statistically optimize the preparation of Rutin-Quercetin (Ru-Qr) dual drug loaded human hair keratin nanoparticles as well as evaluate the characteristics. Materials and Methods: The effects of three independent parameters, namely, temperature (X 1 :10-40 C), surfactant (X 2 : SDS (1), SLS (2), Tween-20 (3)), and organic solvents (X 3 : acetone (1), methanol (2), chloroform (3)) were investigated to optimize the preparation of dual drug loaded keratin nanoparticles, and to understand the effects of dependent parameters namely, drug releasing capacity, average particle size, total antioxidant power, zeta potential, and polydispersity index of Ru-Qr nanoparticles. Optimization was executed by CCD and RSM using statistical software (Design Expert, version 8.0.7.1, Stat-Ease, Inc., Minneapolis, MN, USA). The optimal Ru-Qr dual drug loaded keratin nanoparticles were obtained at temperature (X 1 ): 40ÚC, SDS (X 2 ), and acetone (X 3 ). Results: Under this conditions to achieve highest drug releasing capacity of 98.3%, average size of nanoparticles are 125 nm, total antioxidant power 98.68%, zeta potential 28.09 mV, and polydispersity index of 0.54. Although majority of the experimental values were relatively well matched with the predicted values. Conclusion: This optimization study could be useful in pharmaceutical industry, especially for the preparation of new nano-therapeutic formulations encapsulated with drug molecules. This nanotechnology based drug delivery system is to overcome multi drug resistance and site specific action without affecting other organs and tissues. The methodology adopted in this work shall be useful in improvement of quality of human health. Keywords: Keratin, Quercetin, Response surface methodology, Rutin *Corresponding Author Email: selvaraj.k@klu.ac.in Tel: (+91) 9994972108 Note. This manuscript was submitted on June 5, 2016; approved on July 29, 2016 INTRODUCTION Recently the exploration in drug delivery via nanoparticulate system has given rise to technological innovation in the field of biomedicine [1]. The development of nanomedicine has given a crucial impulse for the fabrication of various nanovehicles such as liposomes, nanoparticles, nanocapsules, etc., for the treatment of degenerative disorders [2]. Among the several nanovectors employed for drug delivery system, nanoparticles have gained interest in comparison to microspheres due to its high surface to volume ratio, small size and ease of penetrating into cells [3]. Nanoparticles are engineered from organic as well as inorganic source. Inorganic nanoparticles such as gold, silver, titanium, iron are widely explored for the fabrication of diagnostic and therapeutic tool [4]. On the other hand organic materials include natural biopoly- How to cite this article Kunjiappan S, Chowdhury A, Somasundaram B, Bhattacharjee Ch, Periyasamy S: Optimization, preparation and characterization of rutin-quercetin dual drug loaded keratin nanoparticles for biological applications. Nanomed J., 2016; 3(4): 253-267. DOI: 10.22038/nmj.2016.7615 Nanomed. J., 3(4): 253-267, Autumn 2016 ORIGINAL RESEARCH PAPER