The invention provides a porous dry matrix preparation comprising at least a polymeric thickener and an excipient ingredient, wherein (1) the content of the polymeric thickener is down to 0.5 w/w % and up to 14 w/w %, (2) the content of the excipient ingredient is down to 30 w/w % and up to 80 w/w %, (3) the void ratio is not less than 20%, and (4) the water activity is not more than 0.55, or water content is not more than 10 w/w %.