The Study Of Felodipine Microemulsion For Dermal Delivery

Felodipine is a d ihydropyridine c alciuma ntagonist w hich is a p otentantihypertensive dr ug. This s tudy intends t o de velop a n ovel microemulsionformulation for dermal deliveryof felodipine. Eucalyptus oil was studied as a new oilphase in microemulsion. T he ad vantage an d d isadvantage w as s tudied b etweeneucalyptus oil and conventional oilphases. Moreover, the irritation ofeucalyptus oilwas studied.The s ubstances o f microemulsion co mponents w ere s elected acco rding t o thecharacteristic, interaction a nd s olubility. O liec a cid, I PM a nd eu calyptus o il w erecompared as o il p hases. D istilled w ater w as u sed as w ater p hase. Tween-80a ndethanol were used as surfactant and cosurfactant separately. The Km value was fixedat1:1. Three ps eudo-ternary p hase d iagram were c onstructed to f ind o ut themicroemulsion area. Nine microemulsion formulations were selected for further study.Nine formulations were studied for physic-chemical characterization includingviscosity, co nductivity, r efractive index, a verage p article s ize a nd s olubility o ffelodipine. The transdermal drug delivery profiles were also studied. Then, F8wasselected as the optimized formulation. It was composed of eucalyptus oil (5%), water(40%), T ween-80(27.5%) a nd e thanol (27.5%). T his formulation po ssessed hi ghpermeation rate, low content of surfactant, and low viscosity.Further s tudy w as p erformed for t he o ptimized f ormulation. T he t ype o fmicroemulsion formulation was d istinguished. Then t he stability and skin irritationwere studied. The formulation was stable according to the study of physical stability,thermodynamic s tability a nd c oncentration stability e xperiment. F elodipineconcentration was stable in three months in ambient temperature. The irritation studyin rabbit skin demonstrated that the formulation had low skin irritating effect. But theeucalyptus oil was proposed of low content in dermaldelivery.Overall, t his st udy d eveloped a p roper microemulsion formulation for d ermaldelivery of felodipine. The optimized formulation got many advantages including easeof preparation, high permeation rate, high drug loading, good stability and low skinirritating. It’s a promising formulation. Furthermore, eucalyptus oil was compare tothe conventional oil phases as a novel oil phase, and it showed good characteristics.