Maryland Commercial Law Section 9-323
§ 9-323.
  (a)   Except as otherwise provided in subsection (b), for purposes of determining the priority of a perfected security interest under § 9-322(a)(1), perfection of the security interest dates from the time an advance is made to the extent that the security interest secures an advance that:
    (1)   Is made while the security interest is perfected only:
      (A)   Under § 9-309 when it attaches; or
      (B)   Temporarily under § 9-312(e), (f), or (g); and
    (2)   Is not made pursuant to a commitment entered into before or while the security interest is perfected by a method other than under § 9-309 or § 9-312(e), (f), or (g).
  (b)   Subsection (a) does not apply to a security interest held by a secured party that is a buyer of accounts, chattel paper, payment intangibles, or promissory notes or a consignor.
  (c)   Except as otherwise provided in subsection (d), a buyer of goods other than a buyer in ordinary course of business takes free of a security interest to the extent that it secures advances made after the earlier of:
    (1)   The time the secured party acquires knowledge of the buyer's purchase; or
    (2)   45 days after the purchase.
  (d)   Subsection (c) does not apply if the advance is made pursuant to a commitment entered into without knowledge of the buyer's purchase and before the expiration of the 45-day period.
  (e)   Except as otherwise provided in subsection (f), a lessee of goods, other than a lessee in ordinary course of business, takes the leasehold interest free of a security interest to the extent that it secures advances made after the earlier of:
    (1)   The time the secured party acquires knowledge of the lease; or
    (2)   45 days after the lease contract becomes enforceable.
  (f)   Subsection (e) does not apply if the advance is made pursuant to a commitment entered into without knowledge of the lease and before the expiration of the 45-day period.