Provided herein are compounds of Formula I, where the variables are as defined herein, and pharmaceutically acceptable salts, solvates or prodrugs thereof having an optical purity of at least 95% of the R enantiomer which have glucagon receptor antagonist or inverse agonist activity. Further, provided herein are pharmaceutical compositions comprising the same as well the the same for use in methods of treating, preventing or ameliorating a condition, disorder or disease for which one or more glucagon receptor antagonist is indicated, including Type I and II diabetes, insulin resistance and hyperglycemia.Formula I
