A fiduciary shall not pay any personal claim of his own until such claim has been approved by the Court of Probate after newspaper notice and hearing, unless the court, for cause shown, waives such notice and hearing. If any such claim is wholly or partly secured, it may be paid out of such security at any time after such approval. The unsecured portion of any such claim and any unsecured claim shall not be paid until after such approval and until after the expiration of the one-hundred-fifty-day period provided for in subsection (a) of § 45a-356.