Juve were on the cusp of taking the tie to extra-time following a remarkable comeback in the Spanish capital, where a Mario Mandzukic brace and Blaise Matuidi's second-half goal wiped out Madrid's 3-0 first-leg advantage.
But Medhi Benatia fouled Lucas Vazquez in the dying moments, prompting referee Michael Oliver to award a penalty.
Buffon's aggressive and prolonged protests earned him a red card from the English official and the veteran Italy international did not let up after the match
"Clearly you cannot have a heart in your chest, but a trash can," he said amid a withering assessment of Oliver's decision.
"On top of that, if you don't have the character to walk on a pitch like this in a stadium like this, you can sit in the stands with your wife, your kids, drinking your Sprite and eating crisps."
UEFA's Control, Ethics and Disciplinary Body will hear Buffon's case on May 31, when a punishment for his red card will be decided and a charge in line with the "general principles of conduct" of European football's governing body will be assessed.
The 40-year-old had previously indicated he would retire at the end of this season but featured in Italy's March friendly against Argentina, even though the Azzurri have no World Cup campaign in prospect.