(T1430-01-06) Preparation and Characterization of Diclofenac Loaded Polymeric Nanoparticles from Mango Seed Kernel Starch

Purpose: The purpose of this study was to prepare and characterize diclofenac containing nanoparticles obtained from starch isolated from mango seed kernels. There are only a few reported studies on the pharmaceutical applications of Mango Seed Kernel Starch (MSKS) and drug carriers produced from this source. This starch can be isolated from mango kernels as an agro-industry waste product which is easily available and cost effective and may have potentially many uses as a pharmaceutical excipient.

Methods: Starch was extracted from mango seed powder using the alkaline method followed by lyophilization to obtain a dried product [1]. The extracted starch was characterized for solubility, pH, moisture content, swelling index, gelatinization temperature and flow properties as well as percentage yield and data was compared to that with corn starch. Mango Seed Kernel Starch Nano Particles (MSKSNPs) were prepared by using mild alkali hydrolysis and an ultra-sonication method [2]. Drug loaded MSKSNPs were prepared by the ethanol injection method [3] using diclofenac sodium as model drug [4]. The drug loaded nanoparticles were characterized for physicochemical properties using Dynamic Light Scattering (DLS), X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), morphology by Transmission Electron Microscopy (TEM), and chemical modifications using Fourier Transform Infra-Red (FTIR). The drug loaded nanoparticles were centrifuged at 3700 rpm for 60 mins. Supernatant was separated and 1 ml of supernatant was diluted with 10 ml of distilled water and sample was analyzed in High Performance Liquid Chromatography (HPLC) for percentage Encapsulation Efficiency (% EE).

Results: The percentage yield of MSKS varied with the solid: solvent ratio and method of drying (Table 1). Maximum yield was obtained when solid: solvent ratio was 1:14. Freeze drying method yielded better granules compared to air drying or oven drying. The aqueous solubility of MSKS was found to be 17±2.8%, pH of 7.0±1.2, % moisture content 7.4±0.8, water holding capacity 79.35±0.8%, swelling power 3.2±0.16g/g, and gelatinization temperature 60°C (Table 2). Particle size was found to be 6.5±0.1microns with a polydispersity index of 0.70±0.0. The chemical integrity of starch was confirmed by FTIR. The MSKSNPs showed amorphous nature with good aqueous solubility. The FTIR spectra showed a strong absorption peak between 3290-3320cm−1 which was attributed to the -OH stretching which leads to the amorphous nature of the starch. The average particle size of drug loaded nanoparticles was found to be 140±3.6 nm with a polydispersity index of 0.42±0.03. The TEM images confirmed the globular structure of MSKSNPs with particle size lower than 100nm. XRD results revealed the degree of crystal size of diclofenac to be 14 nm when compared with pure drug 33 nm which confirms the amorphous nature of MSKSNPs. DSC results of MSKS showed Tp value of 71°C. The drug loaded MSKSNPs showed an % EE 82.34±5.2.

Conclusion: Mango seed starch nanoparticles were successfully synthesized using mild alkali hydrolysis and ultrasonication. The method was relatively simple and took less time than acid hydrolysis. The MSKSNPs were found to be more amorphous compared to the native starch. These nanoparticles have the potential of being a promising drug delivery system for a wide range of therapeutic agents.

References: 1. Shahrim NA, Sarifuddin N, Ismail H. Extraction, and characterization of starch from mango seeds. In Journal of Physics: Conference series 2018 Aug 1 (Vol. 1082, No. 1, p. 012019). IOP Publishing.
2. Ahmad M, Gani A, Hassan I, Huang Q, Shabbir H. Production, and characterization of starch nanoparticles by mild alkali hydrolysis and ultra-sonication process. Scientific Reports. 2020 Feb 26;10(1):1-1.
3. El-Naggar ME, El-Rafie MH, El-Sheikh MA, El-Feky GS, Hebeish A. Synthesis, characterization, release kinetics and toxicity profile of drug-loaded starch nanoparticles. International journal of biological macromolecules. 2015 Nov 1; 81:718-29.
4. Chin SF, Mohd Yazid SN, Pang SC. Preparation, and characterization of starch nanoparticles for controlled release of curcumin. International Journal of Polymer Science. 2014 Jan 1;2014.


Figure 1: Physico chemical characterization of MSKSNPs


Table 1: Effect of process parameters on percentage yield


Table 2: Physico-chemical properties of MSKS compared with corn starch