Role of physical chemical properties in drug relay into skin compartments.

The ability of a drug to reach the interstitial fluid is an important aspect of drug efficacy - as a possible indicator of skin and cell compartment concentration. This overview addresses the relationship of the physical properties of several antibiotics to their ability to enter the interstitial fluid utilizing a cantharidin blister model. By collecting pharmacokinetic data for 12 antibiotics administered orally and 11 intravenously, we compared the fraction of drug that reaches the interstitial fluid (AUC(blister)/AUC(serum)) to partition coefficients. Following data analysis, we found no correlation (p = 0.98 and 0.09, respectively) between hydrophobicity and the ability to reach the interstitium. Both orally and intravenously administered antibiotics display a strong linear correlation (p < 0.001 and p = 0.006, respectively) in the total concentration found in the serum and interstitial fluid indicating that serum concentration may be an important factor in dictating interstitial fluid concentration. This correlation may prove useful in clinical application as a means of determining interstitial fluid concentration by measuring only serum levels.

Intravitreal aflibercept for macular oedema secondary to central retinal vein occlusion in patients with prior treatment with bevacizumab or ranibizumab.

PurposeTo report the visual and anatomic outcomes in eyes with macular oedema (MO) secondary to central retinal vein occlusion (CRVO) that were switched from either intravitreal bevacizumab or ranibizumab to intravitreal aflibercept.MethodsTwo-center retrospective chart review. Eyes with MO secondary to CRVO that received a minimum of three intravitreal injections of bevacizumab or ranibizumab and were switched to intravitreal aflibercept for persistent or recurrent MO not responding to either bevacizumab and/or ranibizumab.ResultsIn all 42 eyes of 42 patients were included in the study. The median visual acuity before the switch was 20/126, 1 month after the first injection of aflibercept 20/89 (P=0.0191), and at the end of the follow-up 20/100 (P=0.2724). The median CRT before the switch was 536 µm, 1 month after the first injection of aflibercept 293.5 µm (P=0.0038), and at the end of the follow-up 279 µm (P=0.0013 compared to before the switch). The median number of weeks between injections before the switch was 5.6 and after the switch was 7.6 (P<0.0001).ConclusionConverting eyes with refractory MO due to CRVO to aflibercept can result in stabilization of the vision, improved macular anatomy, and extension of the injection interval.

Quantification of stratum corneum removal by adhesive tape stripping by total protein assay in 96-well microplates.

BACKGROUND/AIMS: Examination of stratum corneum (SC) content with tape stripping and a colorimetric method is increasingly used. We examined the possible use of microplates in tandem with a colorimetric method to examine SC removed with tape stripping. As a corollary to this examination, the homogeneity of tape strips was examined. METHOD: The commonly used Lowry assay was adapted for 96-well plates. Tapes were divided into four regions and sample disks of 5 mm diameter were taken from each and analyzed for SC mass using the adapted Lowry assay. RESULTS: Homogeneity of SC removal over different areas across a tape strip is limited. CONCLUSION: Quantification of SC by means of a 96-well microplate-based colorimetric method is feasible and shortens the time of analysis. However, when using D-Squame tape disks, SC removal on a limited area of the tape is not predictive for SC removal on the entire tape as removal is inhomogenous. Therefore, SC protein extraction should be performed on a large enough area, eventually on the entire tape when quantifying SC mass removed by tape stripping.

The sex of the individual as a factor in allergic contact dermatitis.

Exogenous and endogenous factors have been implicated in allergic contact dermatitis (ACD); this review explores the sex of the individual as a possible endogenous factor. While there is a clinical impression that women are more skin-reactive than men, upon review this hypothesis appears oversimplified. This review explores sex differences in controlled testing of adult ACD, occupational ACD and juvenile ACD. Further, geographical location and socioeconomic and cultural factors in relation to sex differences in allergic contact dermatitis are discussed. We conclude that female sex could be a factor predisposing to allergic contact dermatitis not so much because of possible differences in intrinsic skin characteristics between the sexes, but more because of different exposure patterns. This conclusion has practical consequences regarding product labelling requirements, occupational risk assessment and legislation.