Notes: Betaxolol (hydrochloride) (Item No. 26285) is an analytical reference standard categorized as a β1-adrenergic receptor antagonist.{25151} Formulations containing β-adrenergic receptor antagonists have been used to enhance physical performance in athletes.{48104,46103} This product is intended for use in analytical forensic applications. This product is also available as a general research tool (Item No. 18625).