  Using a geometric measure of entanglement quantification based on Euclidean
distance of the Hermitian matrices, we obtain the minimum distance between a
bipartite bound entangled $n$- qudit density matrix and the maximally mixed
state.This minimum distance for which entangled density matrices necessarily
have positive partial transpose (PPT) is obtained as
$\frac{1}{\sqrt{\sqrt{d^n(d^n-1)}+1}}$, which is also a lower limit for the
existence of 1-distillable entangled states. The separable states necessarily
lie within a minimum distance of $\frac{R}{1+d^{n-1}}$ from the Identity,where
R is the radius of the closed ball homeomorphic to the set of density matrices,
which is lesser than the limit for the limit for PPT bound entangled states.
Furthermore an alternate proof on the non-emptiness of the PPT bound entangled
states has also been given.
