Abstract:
The aim of this work was to develop Furosemide microemulsion by exploiting the
solubilising effect of microemulsion. Furosemide, a poorly water soluble loop
diuretic, used as antihypertensive agent. Due to low solubility and less bioavailability
of Furosemide, attempts were made to develope and optimize microemulsion
formulation. On the basis of solubility study, Oleic acid, Tween 80 and Propylene
glycol were selected as oil, surfactant and co-surfactant respectively for preparation of
microemulsion. Microemulsion was prepared by water titration method. Pseudo
ternary phase diagrams were constructed at various Tween 80 and Propylene glycol
ratios. The 3:1 ratio represented greater area of microemulsification. The formulated
microemulsions were evaluated for globule size, zeta potential, dissolution study and
FTIR study. In FTIR studies, no interaction was found between drug and excipients.
Various batches were produced using different concentration of oil, surfactant and cosurfactant
yielded microemulsion in the range of 15 to 80 nm. The optimized
microemulsion contained oleic acid 5%w/w, Tween 80: Propylene glycol 55%w/w,
Water 40%w/w. The mechanism of drug release of Furosemide from microemulsion
was observed to follow zero order kinetics. Moreover microemulsion was found to be
stable over a period of one month at 40±2°C / 75±5% RH as per ICH guideline. The
outcome of this study revealed the immense potential of microemulsion for delivery
of Furosemide by improving its solubility and enhancement of dissolution rate.
