Abstract
Purpose: :
Capillary hemangioma (CH) is the most common tumor among infants. Oral propranolol has become an important treatment of CH despite concerns of side effects associated with systemic beta blockers. Topical delivery of propranolol could potentially increase drug concentrations in local periocular tissues and thus increase therapeutic efficacy for periocular CH while minimizing systemic exposure. The objectives of this study were to analyze the concentration of propranolol in periocular tissues and in blood after topical application of propranolol eye drops as compared with systemic intravenous delivery of propranolol.
Methods: :
Each rabbit received either 0.1 ml of propranolol ophthalmic solution (0.1%) in one eye or intravenous propranolol (0.14 mg/kg). The concentration of propranolol in the ipsilateral and contralateral periocular tissues (inner layer and outer layer of eyelids, extraocular rectus muscles, conjunctiva, and fat) and blood was measured by high performance liquid chromatography.
Results: :
After topical instillation of propranolol in one eye, the concentration of propranolol at 1 hour in the ipsilateral periocular tissues (0.36 to 8.9 ug/g) was significantly higher than in contralateral periocular tissues (0.018 to 0.1 ug/g) and blood (not detectable). By contrast, after intravenous systemic delivery, the propranolol concentration was low in both the ipsilateral and contralateral periocular tissues (0.042 to 0.183 ug/g) as well as blood (0.006 ug/ml).
Conclusions: :
Our studies suggest that topical administration can provide therapeutic concentrations of propranolol to the periocular tissues thus providing an alternative to oral propranolol in the treatment of periocular capillary hemangioma.
Keywords: drug toxicity/drug effects • tumors • eyelid