Preparation of pharmaceutical compositions using supercycle vapor phase deposition of metal oxides

A method of preparing coated particles comprising drug-containing core enclosed by an inorganic oxide coating, wherein the drug-containing core comprises a drug, the method comprising the sequential steps of:

• (a) loading particles comprising a drug into a chamber of a reactor;
• (b) performing a first number of first cycles, wherein each first cycle comprises steps (b1)-(b4):
• (b1) applying a vaporous or gaseous first inorganic oxide precursor to the particles in the reactor by pulsing the vaporous or gaseous first inorganic oxide precursor into the reactor;
• (b2) purging using an inert gas or performing one or more pump-purge cycles of the reactor using an inert gas;
• (b3) applying a vaporous or gaseous oxidant to the particles in the reactor by pulsing the oxidant into the reactor;
• (b4) purging using an inert gas or performing one or more pump-purge cycles of the reactor using an inert gas;
• (c) performing a second number of second cycles, wherein each second cycle comprises steps (c1)-(c4):
• (c1) applying a vaporous or gaseous second inorganic oxide precursor to the particles in the reactor by pulsing the vaporous or gaseous second inorganic oxide precursor into the reactor;
• (c2) purging using an inert gas or performing one or more pump-purge cycles of the reactor using an inert gas;
• (c3) applying a vaporous or gaseous oxidant to the particles in the reactor by pulsing the oxidant into the reactor;
• (c4) purging using an inert gas or performing one or more pump-purge cycles of the reactor using an inert gas;
• and
• (d) repeating steps (b)-(c) at least once;
• wherein, the first inorganic oxide precursor and second inorganic oxide precursor are different;
• in each repeat of step (b) the first number is independently selected from 1-10 or 1-20;
• and in each repeat of step (c) the second number is independently selected from 1-10 or 1-20.