Formulation and Permeation Kinetic Studies of Flurbiprofen Gel

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 ofpermeation 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.Keywords: Flurbiprofen, Gel, Diffusion, Permeation enhancers, Skin irritation, Silicone membran

Islamic Monetary Economics: Insights from the Literature

This chapter reviews critical early literature of Islamic monetary economics. The prohibition of Riba has imposed challenges on Islamic economists to come up with the viable alternatives to achieve Islamic monetary policy goals. Our extensive review of theoretical and empirical literature indicates that equity based profit- and loss-sharing instruments have been proposed for conducting open market operations in an interest-free economy. Theoretically, the central bank can achieve desired goals by controlling money supply and profit-sharing ratios. The findings from empirical literature suggest that money demand tend to be more stable in an interest-free economy. Whether monetary transmission works through Islamic banking channel is controversial, but the literature is growing. These findings are not surprising as majority Muslim countries lack sustainable and equitable economic growth. Moreover, these countries suffer from higher inflation and unemployment with little or no monetary freedom due to fixed exchange rate regime, shallow financial markets and strict capital control