Complex sentence: The concentration of azithromycin in the tissues can be over 50 times higher than in plasma, due to ion trapping and its high lipid solubility (volume of distribution is too high).
Split into simpler sentences: The concentration of azithromycin in the tissues can be over 50 times higher than in plasma. This is due to ion trapping and the high lipid solubility (volume of distribution is too high).