Section 60. Pre-incorporation Subscription.— A subscription of shares in a corporation still to be formed shall be irrevocable for a period of at least six (6) months from the date of subscription, unless all of the other subscribers consent to the revocation, or the corporation fails to incorporate within the same period or within a longer period stipulated in the contract of subscription. No pre-incorporation subscription may be revoked after the articles of incorporation is submitted to the Commission.