Preparation and evaluation of fast-dissolving films of etilefrine hydrochloride for practical buccal dosing

Etilefrine hydrochloride (ET) is an important drug in the treatment of hypotension, and parenteral injections and oral tablets are the conventional dosage forms. However, parenteral injections may cause abnormally high plasma levels as well as pain and necrosis, and oral tablets undergo first-pass metabolism. Although fast-dissolving buccal tablets were previously reported, the initial absorption rate was a little slow and the plasma levels were varied extensively. Recently, many films have been developed as novel dosage forms. Therefore, in the present study, film dosage forms containing ET were produced using water-soluble polymers and glycerin (GLY) as excipients to obtain a practical buccal dosage form. Films composed of ET, GLY, and sodium alginate (AL) exhibited good physical characteristics and rapid release in vitro (more than 70% at 2 min). The compacted AL film containing 2 mg ET (1 × 1 cm) exhibited rapid absorption (>19 ng/mL at 0.5 h), maintained an effective plasma level (>7 ng/mL) for a long time period (0.5-4 h), and had an adequate plasma concentration-time profile with a smaller standard error (<15.3 ng/mL). These results suggest that the present compacted buccal film is a superior dosage form of ET for practical use.