BISWAS, DIPJYOTI, et al. “EXTRACTION, MODIFICATION, AND CHARACTERIZATION OF NATURAL POLYMERS USED IN TRANSDERMAL DRUG DELIVERY SYSTEM: AN UPDATED REVIEW”. Asian Journal of Pharmaceutical and Clinical Research, vol. 13, no. 7, July 2020, pp. 10-20, doi:10.22159/ajpcr.2020.v13i7.37756.