Valenta et al. [36] have prepared soya–lecithin aggregates (SLA) bearing ketoprofen as model drug and incorporated these aggregates into hydrophilic and hydrophobic vehicles and studied the permeation using excised rat skin. The permeation rates of SLA incorporated into hydrophilic vehicles like propyleneglycol, polyethyleneglycol 400 and alkyl polyglucosid were found to be approximately 2700–2900 μg through an area of 1 cm2 in 24 h. Ketoprofen released from hydrophobic creams was very low and after 24 h,

around BYL719 300 μg of drug was released. Permeation from the supersaturated systems based on SLA–PEG was fairly good and released 2200–3000 μg through an area of 1 cm2 of rat skin. Comparing their results with ethosomal formulations, it is clear that skin permeation of ethosomal formulations is better than soya–lecithin aggregates. The highest skin permeation with SLA after 24 h, is approximately 2900 μg through an area of 1 cm2 of rat skin, whereas with ethosomes it is approximately 3840 μg through an area of 0.785 cm2 of human skin. Maestrelli et al. [25] prepared β–cyclodextrin (βCyd) and hydroxypropyl–βCyd (HPβCyd) complexes with ketoprofen and incorporated them into multilamellar liposomes for topical delivery. Permeability studies of drug and drug–Cyd complexes, in the form of suspensions or incorporated in liposomes were

GDC-0199 order performed both across artificial membranes and rat skin. Skin permeation rates of suspension forms were surprisingly higher in comparison to liposomes. Drug suspensions having ketoprofen exhibited skin permeation of approximately 670 μg in 24 h compared to 630 μg in case of lipsosomes bearing ketoprofen. Similar

trends were observed with drug–βCyd and drug–HPβCyd complexes and their liposomes. Permeation of ketoprofen through skin of all the formulations is substantially lower compared to ethosomal formulations. Predicted in vivo drug plasma concentration was estimated assuming drug in a patch of 50 cm2. Actually plasma ketoprofen concentration above 1 μg/ml is reported to elicit analgesic effect [33] and in order to achieve steady state plasma concentration above 1 μg/ml the ethosomal preparation is to be fabricated in a patch size Tangeritin of 50 cm2. However by increasing the amount of drug in the formulation, the patch size to achieve the same concentration can be reduced. Steady state plasma concentration from all the formulations was investigated to be in a narrow range varying from 1.21±0.13 to 1.52±0.17 μg/ml. However this is not a point of concern as the values are well above 1 μg/ml, which is sufficient to generate therapeutic response in contrast to hydroalcoholic drug solution that remained in sub therapeutic range using a patch of 50 cm2. Highest transdermal flux and consequently highest Pss (1.52±0.17 μg/ml) was observed with formulation E3 whereas lowest Pss of 1.21±0.