Intradermal mini - needle interface and associated devices and methods

A method for transferring a liquid through at least one layer of the skin by use of an intradermal mini-needle interface including:

• (a) a penetration limiter providing a skin contact edge;
• (b) a hypodermic needle having a beveled penetrating portion protruding forward beyond said skin contact edge by no more than 3 mm, said penetrating portion having a central needle axis;
• and
• (c) at least one skin contact surface defining a skin contact plane parallel to, or at a shallow angle to, said needle axis, said skin contact plane intersecting said skin contact edge substantially at a base of said penetrating portion,
• the method comprising the steps of:
• (i) penetrating at least one layer of the skin with the hypodermic needle;
• (ii) bringing the hypodermic needle to a position with its central axis at a shallow angle to the initial local surface of the skin such that the hypodermic needle extends into a portion of the skin which is not overlaid by the penetration limiter;
• and
• (iii) transferring a liquid via the hypodermic needle through at least one layer of the skin.

A method for introducing a liquid through at least one layer of the skin, the method comprising the steps of:

• (a) penetrating at least one layer of the skin with a hollow needle;
• (b) maintaining the hollow needle with its central axis at an angle of less than 45 degrees to the initial local surface of the skin;
• and
• (c) directing a high energy jet of the liquid along the hollow needle so as to cause directional penetration of the liquid through tissue beyond an end of the hollow needle.