Drug Design, Development and Therapy (Nov 2016)

Smart nanocrystals of artemether: fabrication, characterization, and comparative in vitro and in vivo antimalarial evaluation

  • Shah SMH,
  • Ullah F,
  • Khan S,
  • Shah SMM,
  • Matas MD,
  • Hussain Z,
  • Minhas MU,
  • AbdEl-Salam NM,
  • Assi KH,
  • Isreb M

Journal volume & issue
Vol. Volume 10
pp. 3837 – 3850

Abstract

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Syed Muhammad Hassan Shah,1 Farhat Ullah,2 Shahzeb Khan,2,3 Syed Muhammad Mukarram Shah,4 Marcel de Matas,5 Zahid Hussain,6 Muhammad Usman Minhas,7 Naser M AbdEl-Salam,8 Khaled Hafez Assi,3 Mohammad Isreb3 1Department of Pharmacy, Sarhad University of Science & Information Technology, Peshawar, 2Department of Pharmacy, University of Malakand, Chakdara, Pakistan; 3Institute of Life Sciences Research, School of Pharmacy, University of Bradford, West Yorkshire, 4Department of Pharmacy, University of Swabi, KPK, Pakistan; 5SEDA Pharmaceutical Development Services, The BioHub at Alderley Park, Cheshire, UK; 6Faculty of Pharmacy, Department of Pharmaceutics, Universiti Teknologi MARA, Selangor, Malaysia; 7Faculty of Pharmacy & Alternative Medicine, The Islamia University of Bahawalpur Pakistan, Bahawalpur, Pakistan; 8Riyadh Community College, King Saud University, Riyadh, Saudi Arabia Abstract: Artemether (ARTM) is a very effective antimalarial drug with poor solubility and consequently low bioavailability. Smart nanocrystals of ARTM with particle size of 161±1.5 nm and polydispersity index of 0.172±0.01 were produced in <1 hour using a wet milling technology, Dena® DM-100. The crystallinity of the processed ARTM was confirmed using differential scanning calorimetry and powder X-ray diffraction. The saturation solubility of the ARTM nanocrystals was substantially increased to 900 µg/mL compared to the raw ARTM in water (145.0±2.3 µg/mL) and stabilizer solution (300.0±2.0 µg/mL). The physical stability studies conducted for 90 days demonstrated that nanocrystals stored at 2°C–8°C and 25°C were very stable compared to the samples stored at 40°C. The nanocrystals were also shown to be stable when processed at acidic pH (2.0). The solubility and dissolution rate of ARTM nanocrystals were significantly increased (P<0.05) compared to those of its bulk powder form. The results of in vitro studies showed significant antimalarial effect (P<0.05) against Plasmodium falciparum and Plasmodium vivax. The IC50 (median lethal oral dose) value of ARTM nanocrystals was 28- and 54-fold lower than the IC50 value of unprocessed drug and 13- and 21-fold lower than the IC50 value of the marketed tablets, respectively. In addition, ARTM nanocrystals at the same dose (2 mg/kg) showed significantly (P<0.05) higher reduction in percent parasitemia (89%) against P. vivax compared to the unprocessed (27%), marketed tablets (45%), and microsuspension (60%). The acute toxicity study demonstrated that the LD50 value of ARTM nanocrystals is between 1,500 mg/kg and 2,000 mg/kg when given orally. This study demonstrated that the wet milling technology (Dena® DM-100) can produce smart nanocrystals of ARTM with enhanced antimalarial activities. Keywords: artemether, milling, smart nanocrystals, nanosuspension, in vitro dissolution, antimalarial activity

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