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A photographic image of an eyelid skin after frozen sectioning and hematoxylin and
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This work investigated the permeability of lidocaine across human eyelid skin and compared this with published data for abdominal skin to understand the characteristics of this type of skin and whether topical anaesthesia for eyelid surgery may be feasible. Eyelid skin is thought to have a relatively high permeability to drugs, however how this com...
Context in source publication
Context 1
... factors believed to affect skin permeability include the number of cell layers in the SC and the overall thickness of the SC layer. Figure 3 shows a histological section of full thickness eyelid skin with the stained SC layer being easily visible. The thickness of the eyelid skin SC was measured to be 14.9 ± 2.9 μm (n= 27), which is 31 % lower than the value reported for abdominal skin (21.8 ± 2.2 μm) [20]. ...
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Des études cliniques rétrospectives ont suggéré un effet protecteur de l’anesthésie locorégionale contre les récidives après chirurgie carcinologique, donnant une nouvelle dimension à la prise en charge de la douleur périopératoire. Le premier objectif de ce travail était de montrer les effets antitumoraux directs de la lidocaïne, un anesthésique l...
Objectives The study aimed to evaluate and compare various commercially available local anesthetic solutions.
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Citations
... In the human eyelid, the thickness of the stratum corneum layer, a rate-limiting barrier in skin penetration of drugs, is approximately 14.9 μm, thicker than in rabbit eyelids (approximately 7.5 μm) [15,38]; therefore, epinastine penetration into the eyelid can be limited in humans compared with that in rabbits. However, it is plausible that sufficient levels of epinastine can be distributed to the conjunctival tissues in humans following eyelid application since significant repressions of ocular itching and conjunctival hyperemia have been demonstrated in subjects with allergic conjunctivitis after once-daily eyelid application of 0.5% epinastine cream [39]. ...
To reveal the penetration of epinastine, an anti-allergic ophthalmic agent, into the eyelid and its distribution to the conjunctiva after administration of a cream formulation on rabbit eyelid skin.
Experimental study.
Rabbits were treated with 0.5% epinastine cream on hair-shaved eyelids, followed by preparation of eyelid tissue slices to determine spatial tissue distribution of epinastine by liquid chromatography-tandem mass spectrometry (LC-MS/MS) quantification using laser-microdissected tissues and desorption electrospray ionization mass spectrometry imaging (DESI-MSI). In addition, following either eyelid application of 0.5% epinastine cream or ocular instillation of 0.1% epinastine eye drops, concentration-time profiles of epinastine in the palpebral conjunctiva and bulbar conjunctiva were determined using LC-MS/MS.
Laser microdissection coupled with LC-MS/MS analysis detected high concentrations of epinastine around the outermost layer of the eyelid at 0.5 h post-administration that gradually diffused deeper into the eyelid and was distributed in the conjunctival layer at 8 and 24 h post-administration. Similar time-dependent drug distribution was observed in high-spatial-resolution images obtained using DESI-MSI. Epinastine concentrations in the conjunctival tissues peaked at 4–8 h after administration of 0.5% epinastine cream and then decreased slowly over 72 h post-administration. In contrast, epinastine concentrations peaked quickly and decreased sharply after epinastine eye drop administration.
After the application of epinastine cream to the eyelid skin, epinastine gradually permeated the eyelid. The compound was retained in the conjunctiva for 8–24 h post-administration, indicating that epinastine cream is a promising long-acting formulation for treating allergic conjunctivitis.
... Frequent itching of periorbital skin and subsequent steroid application, as well as the thinness of the eyelid skin, may explain the clinical involvement observed (2,8). When topical steroids are applied to the face, including the eyelids, direct exposure affects the facial skin, particularly due to the thinner stratum corneum and higher drug permeability of the eyelid skin, which may contribute to the characteristic occurrence of steroid-associated rosacea (9)(10)(11). Furthermore, in line with previous research findings, the cumulative dose and cumulative duration of topical steroid use are associated with the risk of developing diabetes (12). ...
Nitrogen doped carbon dots (N-doped C-dots) were prepared using polyethyleneimine (PEI) and citric acid (CA) as precursors via the hydrothermal method. Various weight ratios of PEI and CA, 1:0.5, 1:1, and 1:2, were used in the synthesis of N-doped C-dots. The N-doping of prepared C-dots was confirmed with an FT-IR peak that was observed at 1652 cm⁻¹ assigned to N-H bending. The hydrodynamic diameters of prepared N-doped C-dots were 70.2±6.9, 32.2±4.7, and 11.5±3.1 nm by DLS measurements, and surface charges values were 1.32±0.8, 0.14±0.2, and -1.57±0.7 mV, for 1:0.5, 1:1, and 1:2 weight ratio based on PEI of CA, respectively. A high quantum yield 53±4.8% according to quinine sulfate standard was determined for 1:1 C-dot prepared from 1:1 weight ratio of PEI:CA. The C-dots were found to inhibit growth of both Gram-negative and Gram-positive bacteria with no noted toxicity to mammalian cells in vitro. Skin permeation studies indicate that the particles permeate into and through the dermis within hours, indicating their potential use for topical administration.
