Kasta Gurning1,*, Iksen1, Helen Anjelina Simanjuntak1, Hermawan Purba1,2
1Department of Pharmacy, Sekolah Tinggi Ilmu Kesehatan Senior Medan, Medan-20141, INDONESIA.
2Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Sumatera Utara, Medan-20155 INDONESIA.