NOVELTY - Large particle diameter medicinal intercalated hydrotalcite comprises (wt.%) brufen (33-47) and water (9-13).    USE - Large particle diameter medicinal intercalated hydrotalcite.    ADVANTAGE - The medicinal intercalated hydrotalcite uses water as single solvent, thus it is more environmentally friendly; uses one-off reaction, thus it is more energy-saving; has controlled growth via regulating crystallization time and crystallization temperature to product with larger particle diameter and more uniform distribution, thus prolonging releasing time of medicine, and improving the sustained release effect.    DETAILED DESCRIPTION - Large particle diameter medicinal intercalated hydrotalcite of formula (M2+)1-x(M3+)x(OH)2(IBM-)a(D raised to n-)b.mH2O, comprises (wt.%) brufen (33-47) and water (9-13).    M2+=Mg2+, Zn2+, Fe2+ or Ca2+;    M3+=Al3+ or Fe3+;    IBU=intercalated univalent brufen anion;    D raised to n-=inorganic anion;    x=0.2-0.33;    a=number of IBU-;    b=number of D raised to n-;or    a+nx b=x;and    m=number of crystallization water.    An INDEPENDENT CLAIM is included for a method for preparing large particle diameter medicinal intercalated hydrotalcite comprising dissolving M2+ metal salt and M3+ metal salt into decarbonation deionized water to prepare into mixed salt solution, with mol ratio of M2+/M3+ at 2-4, mol concentration of divalent metal ions at 0.3-0.83 M, mol concentration of the trivalent metal ions at 0.15-0.2 M, and taking sodium hydroxide (NaOH) and IBU and decarbonation deionized water to prepare into mixed aqueous alkali, with mol ratio of NaOH and the IBU at 5-6; putting mixed salt solution into sealed reaction vessel with agitation, gradually adding mixed aqueous alkali to mixed salt solution within 0.5-1 hour until pH 9-11, wholly turning into high pressure reaction kettle and sealing; putting high pressure reaction kettle at 100-180 degrees C, and putting serofluid in the system at high temperature and high pressure for crystallization reaction for 18-72 hours; and centrifuging serofluid after crystallization reaction, washing settlement obtained after centrifuging serofluid with decarbonation deionized water until neutral, washing with absolute ethyl alcohol, drying in vacuum for 24-72 hours at 60-80 degrees C, and obtaining IBU-layered double hydroxides (LDH).