Formulation and Permeation Kinetic Studies of Flurbiprofen Gel|
Ayoub, Rao Khurram; Murtaza, Ghulam; Imran, Muhammad; Khan, Shujaat Ali; Mir, Sadullah; Khan, Abida Kalsoom; Azhar, Saira; Mehmood, Zahid; Sajjad, Ashif & Shah, Syed Nisar Hussain
Purpose: To investigate the in vitro permeation and drug release kinetics of flurbiprofen gel.
Methods: Thirteen batches (G1, G2 … G13) of flurbiprofen gels were prepared using different ratios of
permeation enhancers, i.e., propylene glycol (PG) and polyethylene glycol (PEG), by response surface
methodology (RSM). Viscosity, pH, spreadability, consistency and drug content of the flurbiprofen gels
were measured. Permeation experiments were conducted using silicone membrane in a modified Franz
diffusion cell. Permeation parameters determined include diffusion coefficient (D), Flux (J), lag time
(tLag), permeation coefficient (Kp), input rate (IR) and enhancement ratio (ER). Primary skin irritation
test was performed for the optimized gel, G3, using 11 human volunteers.
Results: Maximum solubility (72.15 ± 0.02 mg/mL) of flurbiprofen was observed in a mixture (2:1) of
methanol and water. Partition coefficient (Ko/w) was determined as logP = 3.68 ± 0.11. The gels were
stable under various storage conditions, and were homogenous, crystalline and transparent. Viscosity,
pH, spreadability, consistency and drug content were in the range of 150 – 178 × 102 cps, 5.42 - 5.75,
5.0 - 7.0 g.cm/s, 3.0 - 9.0 mm, and 97.99 - 99.86 %, respectively. No irritation or lesions (erythma,
redness and ulceration) occurred in human volunteers over a 30-day period. The optimized formulation,
G3, showed maximum flux through silicone membrane.
Conclusion: PG and PEG are effective enhancers of flurbiprofen from various formulations when used
in various ratios.
Flurbiprofen; Gel; Diffusion; Permeation enhancers; Skin irritation; Silicone membrane