Monetary values of increasing life expectancy: Sensitivity to shifts of the survival curve

Individuals' monetary values of decreases in mortality risk depend on the magnitude and timing of the risk reduction. We elicited stated preferences among three time paths of risk reduction yielding the same increase in life expectancy (decreasing risk for the next decade, subtracting a constant from or multiplying risk by a constant in all future years) and willingness to pay (WTP) for risk reductions differing in timing and life-expectancy gain. Respondents exhibited heterogeneous preferences over the alternative time paths, with almost 90 percent reporting transitive orderings. WTP is statistically significantly associated with life-expectancy gain (between about 7 and 28 days) and with respondents' stated preferences over the alternative time paths. Estimated value per statistical life year (VSLY) can differ by time path and averages about $500,000, roughly consistent with conventional estimates obtained by dividing estimated value per statistical life by discounted life expectancy.

Identifying the effects of scientific information and recommendations on physicians' prescribing behavior

We investigate how the prescribing behavior of physicians reacts to scientific information and recommendations released by public authorities. Taking the example of antidepressant drugs, we use French panel data on exhaustive prescriptions made by a representative sample of general practitioners to more than 110,000 depressed patients between 2000 and 2008. New results revealing an increase in suicidal thinking among children taking selective serotonin reuptake inhibitors (SSRIs) were reported in 2004 and prompted the release of new guidelines by public health authorities. We identify the effect of this unexpected warning on physicians' drug choices while addressing the possibility that patients heterogeneity may be correlated with unobserved physician characteristics. While the warning decreased the average probability of prescribing SSRIs, we find that physicians' responses to the warning were very heterogeneous and larger if the physician had a higher preference for prescribing SSRIs before the warning.

In vitro studies on the transdermal formulation containing pentoxifylline microspheres with poly-L-lactide

In this study, microspheres of Pentoxifylline (PTX) obtained with poly-L-lactide were investigated for drug-polymer ratios of 1:1, 1:5 and 1:10 and the HPLC results of PTX in the microspheres indicated that 1:5 drug-polymer ratio had the highest loading efficiency. For HPLC analysis acetonitrile-water (40:60) was selected as the mobile phase because it yielded the most favorable k' values. Retention times are 4.51 and 7.88 min. for PTX and internal standard (phanecetin), respectively. Calibration curves were linear (r2 > 0.999) in the range of 0.5-10 mg/ml with no significant difference from the origin. Then, matrix controlled transdermal systems containing plain drug or microspheres of drug were prepared. Carrageenan was chosen as a matrix polymer. In vitro release data of the formulations were evaluated kinetically. The results obtained indicate that PTX containing microspheres can be incorporated in carrageenan matrices to form a transdermal therapeutic system.

In vivo studies on nasal preparations of ciprofloxacin hydrochloride

Gel formulations of ciprofloxacin hydrochloride (CPH) were prepared with bioadhesive polymers such as hydroxypropyl methylcellulose (HPMC), hydroxyethyl cellulose (HEC) and methylcellulose (MC). They were administered into the nasal cavity of rabbits. A nasal aqueous suspension of CPH with glycerol was also applied. In addition, the effect of Tween 80 as penetration enhancer was examined. The agar plate diffusion technique was applied for the assay of CPH. The results were compared with oral and intravenous administrations. The bioavailability of the CPH gel formulation prepared with HPMC was almost identical to that of the oral route. Other nasal formulations with HEC and MC had bioavailabilities lower than oral preparations. The relative bioavailabilities for the formulation containing HEC and MC were 48.7 and 45.54%, respectively. To increase the bioavailabilities, 1% (w/w) of Tween 80 was added. The bioavailability of these gel formulations increased to 63.54 and 55.72%, respectively. Experiments carried out on rabbits showed that the nasal administration of CPH bioadhesive gel formulation containing HPMC may be an alternative to the oral route.