How does Antonio changed in the course of The Merchant of Venice?What is Antonio's character development?

The text of The Merchant of Venice
indicates that Antonio doesn't change at all through the course of the play. In this
regard, the literary element of character change would be antithetically presented in a
staunchly unchanging character who holds fast to errors despite drastic situations that
call for a change of character. One instance of Antonio's errors, which are derived from
his character traits, is the fact that he seems to actually lie in the opening scene
when he tells Salarino and Salanio that his wealth is not all in one venture nor
dependent upon the financial success of that one year. His dishonest remarks to Salarino
and Salario are revealed in his conversation with Bassanio in which he says that "all my
fortunes are at sea; / Neither have I money nor commodity / To raise a present
sum."

Another instance of Antonio's errors is what is
revealed about his behavior while Bassanio and he are in negotiation for a loan with
Shylock, who reveals that Antonio has hurled names at Shylock and spit on him and that
he "did void [his] rheum upon [Shylock's] beard" and " foot [Shylock] as [he would]
spurn a stranger cur." Antonio doesn't deny that he took such base actions, in fact, he
confirms it: "I am as like to call thee so again, / To spit on thee again, to spurn thee
too."

During the conclusion of the trail, when Shylock's
punishment is being decided, Antonio successfully contributes to Shylock's punishment by
continuing to persecute and impose his will upon Shylock and requiring, among other
things, that Shylock convert to Christianity. Later, this same manipulative streak is
displayed when he requires that Bassanio give Portia's ring to the lawyer/Portia against
his will, as he swore to never part with it. He even speaks for Bessanio by pledging his
own life again and saying that Bessanio swears to never break another oath given to
Portia.

The most telling point that indicates there is no
change in Antonio is that at the close of the play, he still thinks of Shylock as a
despicable Jew and doesn't even entertain an idea that recognizes Shylock as a human,
and one who has been seriously mistreated, so seriously as to drive him to strike a
bargain for a pound of flesh.