Effect of the sustained release excipients on the release rate of ginsenoside Rg1 and ginsenoside Rb1 in sustained-release tablet of Panax notoginsenosides Effect of Panax notoginsenosides on excretion and degradation of extracellular matrix of human renal tubular epithelial cells induced by uremic serum Formulation optimization of panax notoginsenoside orally fast disintegration tablets