A method of preparing a pharmaceutical product comprises the steps of (a) providing a neat active pharmaceutical ingredient (API) which complies with at least five of the following parameters (i)-(viii) as determined by using a FT4 powder rheometer: (i) specific basic flow energy (sBFE) of at most 60 mJ/g； (ii) stability index (SI) of 0.75 to 1.25； (iii) specific energy (SE) of at most 10 mJ/g； (iv) major principle stress at 15 kPa (MPS-15) of at most 40； (v) flow function at 15 kPa (FF-15) of at least 1.3； (vi) consolidated bulk density at 15 kPa (CBD-15) of at least 0.26 g/mL； (vii) compressibility of at most 47 %； and (viii) wall friction angle (WFA) of at most 40°； (b) dispensing the neat API of step (a) into a bottom part of a pharmaceutical carrier using a vacuum assisted metering and filling device； and (c) encapsulating the bottom part of said pharmaceutical carrier with a complementary lid part of said pharmaceutical carrier, thereby producing a pharmaceutical product.
