When accused fails to sign inventory of seized drugs

Dear PAO,

Can a person charged for possessing illegal drugs and paraphernalia be acquitted if he did not sign the certificate of inventory purportedly indicating the items allegedly seized from him or her at the time of arrest? From what I have read before, it is important that the accused signs the inventory. Does that mean that the procedure becomes defective if the accused did not sign the document which will result in his/her acquittal?