The ornamental design for a cap of container for mixing medications, as shown and described.
FIG. 1 is a front elevational view of a cap of container for mixing medications showing my new design, the rear elevational view being identical thereto;
FIG. 2 is a top plan view thereof;
FIG. 3 is a bottom plan view thereof;
FIG. 4 is a right side elevational view thereof, the left side elevational view thereof being identical thereto;
FIG. 5 is a sectional view thereof taken along line 5-5 of FIG. 1;
FIG. 6 is a bottom perspective view thereof;
FIG. 7 is an environmental perspective view thereof; and,
FIG. 8 is an environmental front elevational view thereof.
The broken lines are for the purpose of illustrating environmental structure only and form no part of the claimed design.