As one passes across a curved surface or interface, a jump in pressure occurs. The smaller the drop, the greater is its inner pressure. Surface tension is at the origin of the overpressure existing in the interior of drops and bubbles.
Δ p = pinside - poutside = γ (1/ R + 1/R') = γ C
The increase in hydrostatic pressure Δ p that occurs upon traversing the boundary between two fluids is equal to the product of the surface tension γ and the curvature of the surface C= (1/ R + 1/R'), where R and R' are the radii of curvature of the surface. For a sphere, R=R'.
Δ p = pinside - poutside = (2 γ ) / R !!!!!