Skin penetration and photoprotection of topical formulations containing benzophenone-3 solid lipid microparticles prepared by the solvent-free spray-congealing technique

Abstract

Purpose: Solid-lipid microparticles loaded with high amounts of the sunscreen UV filter benzophenone-3 were prepared by spray congealing with the objective of decreasing its skin penetration and evaluate whether the sunscreen’s photoprotection were impaired by the microencapsulation process. Methods: The microparticles were produced using the natural lipids carnauba wax or bees wax and three different concentrations of benzophenone-3 (30, 50 and 70%) using spray congealing technique. Results: The microparticles presented properties suitable for topical application, such as spherical morphology, high encapsulation efficiency (95.53–102.2%), average particle sizes between 28.5 and 60.0?µm with polydispersivities from 1.2 to 2.5. In studies of in vitro skin penetration and preliminary stability, formulations of gel cream containing carnauba wax solid lipid microparticles and 70% benzophenone-3 when compared to the formulation added of bees wax solid-lipid microparticles containing 70% benzophenone-3, was stable considering the several parameters evaluated and were able to decrease the penetration of the UV filter into pig skin. Moreover, the formulations containing solid lipid microparticles with 70% benzophenone-3 increased the photoprotective capacity of benzophenone-3 under UV irradiation. Conclusion: The results show that spray-congealed microparticles are interesting solid forms to decrease the penetration solar filters in the skin without compromising their photoprotection.     

Microdialysis Technique as a Method to Study the Percutaneous Penetration of Methyl Nicotinate Through Excised Human Skin,Reconstructed Epidermis,and Human Skin In Vivo

Purpose. The aim was to assess the feasibility of cutaneousmicrodialysis as a method to study percutaneous penetration of methyl nicotinatethrough human skin in vitro and in vivo. Methods. Microdialysis was applied in vitro in excised human skin,in isolated dermis, in reconstructed human epidermis and in vivo inthe volar forearm skin of volunteers using methyl nicotinate (MN) asa model compound. After topical application of MN, aliquots of theperfusate were collected and analyzed for the presence of MNspectrophotometrically and by HPLC. In vivo, visual scoring and laser Dopplerperfusion imaging (LDPI) were used to monitor the effects on skinblood flow. Results. In vitro, MN was detected in the dialysate after a 1 minexposure of excised skin to concentrations as low as 25 mM. Higherconcentrations up to 500 mM showed increased levels. Prolongationof the application time to 60 min resulted in increased levels of MNin the perfusate as the duration of application increased. Reconstructedepidermis and isolated dermis showed an almost 2- and 20-fold higherpenetration compared to excised skin, respectively. In vivo, LDPImeasurements showed a rapid increase in skin blood flow afterapplication of 25 to 100 mM MN for 1 min. MN was only detectable inthe microdialysate after application of 100 mM for 10 min (two ofthree subjects). Conclusions. Cutaneous microdialysis may be a tool for comparativestudies linking responses in human skin in vivo to in vitro data usingthe same technique and endpoint.     

Role of P-Glycoprotein on the CNS Disposition of Amprenavir (141W94), an HIV Protease Inhibitor

Purpose. To determine the role of P-glycoprotein (Pgp) on the CNS penetration of the HIV protease inhibitor (PI) amprenavir (141W94) and to test the hypothesis that co-administration of a second HIV PI (ritonavir) could enhance amprenavir's brain penetration in vivo. Methods. Pgp-mediated efflux was investigated in vitro with Caco-2 cells and in vivo by whole-body autoradiography (WBA). 'Genetic'mdrla/lbdouble knockout mice, 'chemical' Pgp knockout mice generated by administration of the Pgp inhibitor GF120918, and mice pretreated with ritonavir were used in WBA studies to investigate the effects of Pgp modulation on the CNS penetration of amprenavir. Results. Amprenavir, indinavir, ritonavir, and saquinavir had 2-to 23-fold higher transport rates from the basolateral to apical direction than from the apical to basolateral direction across Caco-2 monolayers. Incubation with GF 120918 negated this difference, suggesting that the efflux was Pgp-mediated. WBA studies demonstrated a 13- and 27-fold increase in the brain and a 3.3-fold increase in the CSF concentrations of amprenavir in mice pretreated with GF120918 and in mdrla/lbdouble knockout mice. In contrast, pretreatment with ritonavir did not alter the CNS exposure of amprenavir. Conclusions. These results provide evidence that amprenavir and other HIV PIs are Pgp substrates and that co-administration of a specific Pgp inhibitor will enhance amprenavir's CNS penetration in vivo. These results will have an important therapeutic impact in the treatment of AIDS dementia.     

Development of piperic acid derivatives from Piper nigrum as UV protection agents

Abstract

Context: There is a need for the discovery of novel natural and semi-synthetic sunscreen that is safe and effective. Piperine has a UV absorption band of 230–400?nm with high molar absorptivity. This compound has a high potential to be developed to sunscreen.

Objective: This study develops new UV protection compounds from piperine by using chemical synthesis.

Materials and methods: Piperine was isolated from Piper nigrum L. (Piperaceae) fruits, converted to piperic acid by alkaline hydrolysis, and prepared as ester derivatives by chemical synthesis. The piperate derivatives were prepared as 5% o/w emulsion, and the SPF values were evaluated. The best compound was submitted to cytotoxicity test using MTT assay.

Results: Piperic acid was prepared in 86.96% yield. Next, piperic acid was reacted with alcohols using Steglich reaction to obtain methyl piperate, ethyl piperate, propyl piperate, isopropyl piperate, and isobutyl piperate in 62.39–92.79% yield. All compounds were prepared as 5% oil in water emulsion and measured its SPF and UVA/UVB values using an SPF-290S analyzer. The SPF values (n?=?6) of the piperate derivatives were 2.68?±?0.17, 8.89?±?0.46, 6.86?±?0.91, 16.37?±?1.8, and 9.68?±?1.71. The UVA/UVB ratios of all compounds ranged from 0.860 to 0.967. Cytotoxicity of isopropyl piperate was evaluated using human skin fibroblast cells and the IC₅₀ was equal to 120.2?μM.

Discussion and conclusion: From the results, isopropyl piperate is an outstanding compound that can be developed into a UV protection agent.     

尼美舒利乳胶剂的制备及其体外透皮扩散研究

目的：研制尼美舒利（NIM）乳胶剂。方法：用剪切一高压均质法制备NIM亚微乳,并对其体外透皮扩散进行考察,再与凝胶基质混合制成NIM乳胶剂。对其处方及制备工艺进行了正交筛选,对其粒径、稳定性及体外透皮效果进行了考察。结果：用最佳处方及制备工艺制备的NIM亚微乳平均粒径为182．8nm,不耐强光及高温,体外透皮效果与NIM凝胶相比有明显改善,累积透过量Q有显著性差异（P〈0．05）,稳态透皮速率J有非常显著性差异（P〈0．01）。结论：NIM乳胶剂具有较好的促进NIM透皮扩散作用,值得进一步研发。     

三七提取物抗谷氨酸损伤PC12细胞的活性筛选及成分分析

目的 研究三七提取物抗谷氨酸损伤PC12细胞的活性筛选,并分析活性部位的化学成分。方法 以谷氨酸损伤PC12细胞为模型,实验分为对照组、模型组、石油醚提取物和超临界CO₂萃取物组（6.25、12.50、25、50、100、200 μg/mL）。采用MTT比色法对三七石油醚提取和超临界CO₂萃取部位进行活性筛选,并利用气质联用技术（GC-MS）对三七石油醚提取物和超临界CO₂萃取物进行化学成分鉴定分析。结果 与对照组比较,25 mmol/L谷氨酸作用PC12细胞24 h,细胞生长抑制率接近50%。不同浓度石油醚提取物组与模型组的细胞存活率差异有统计学意义（P<0.05）,25、50、100 μg/mL石油醚提取物组间的细胞存活率差异有统计学意义（P<0.05）。不同浓度超临界CO₂萃取物组与模型组的细胞存活率差异有统计学意义（P<0.05）,25、50、100 μg/mL超临界CO₂萃取物组间的细胞存活率差异有统计学意义（P<0.05）。50、100 μg/mL超临界CO₂萃取物组与石油醚提取物组的细胞存活率差异有统计学意义（P<0.05）。经GC-MS技术分析得出,超临界CO₂萃取物中主要的脂溶性成分人参炔醇含量（13.09%）高于石油醚提取物（4.10%）。结论 石油醚提取物与超临CO₂萃取物对PC12细胞均有保护作用,但超临界CO₂萃取物具有较好的细胞保护作用。     

白藜芦醇三甲醚乳胶体外经皮渗透研究

目的制备白藜芦醇三甲醚(BTM)乳胶,考察载药量、促渗剂及其组合对BTM经皮渗透性的影响,评价药物透皮给药的可行性。方法以卡波姆940为凝胶基质制备BTM乳胶,选用改良Franz扩散池,以离体乳猪腹部皮肤为屏障进行体外经皮渗透实验,用HPLC-UV法测定各时间点接收室中药物浓度,计算经皮渗透动力学参数。结果载药量由1%增加到2%时,BTM 24 h单位面积渗透量增加1倍,2%与4%乳胶渗透量没有统计学差异(P>0.1)。促渗剂均可显著促进BTM透皮吸收,其透皮速率为:2%香叶醇>2%肉豆蔻酸异丙酯>2%油酸>2%氮酮>2%橙花叔醇>无促渗剂;香叶醇的浓度大小对BTM的透皮吸收无明显影响(P>0.05);与单用2%香叶醇相比,促渗剂联用(2%香叶醇+2%丙二醇、2%香叶醇+2%肉豆蔻酸异丙酯)未显示出显著协同促渗作用(P>0.05),而2%香叶醇+2%异丙醇则显示弱拮抗促渗作用(P<0.05)。结论常用促渗剂均能不同程度促进BTM经皮渗透,载药量为2%、促渗剂为2%香叶醇时,BTM体外透皮可达最大吸收。但BTM体外透皮吸收具有饱和性,该结果为BTM经皮给药研究提供了基础。     

Self Promotion of Deep Tissue Penetration and Distribution of Methylsalicylate After Topical Application

Purpose. To determine how changes in cutaneous blood flow induced in-vivo by methylsalicylate (MeSA), compared to non-rubefacient trie-thanolamine salicylate (TSA), affected topical salicylate absorption and distribution, and to assess formulation therapeutic potential by comparing tissue concentrations to published antiinflammatory concentrations. Methods. Flux of salicylate from MeS A and TSA formulations applied to full-thickness rat skin was determined using in vitro diffusion cells. Anaesthetised rats were then used to quantify salicylate concentrations in plasma and tissues underlying the application site for the two formulations over a 6h period. In vitro and in vivo absorption profiles were then compared and the effect of MeSA on cutaneous blood flow assessed. Results. In vitro flux of salicylate from the MeSA formulation was 40% higher, though after correcting for differences in formulation concentrations the ratio of permeability coefficients was reversed. Contrary to the in vitro predictions, in vivo tissue and plasma concentrations of salicylate in rats rose rapidly in the first 1 hr and were more than the predicted 1.4-fold higher for MeSA. This effect was mirrored by the increase in blood flow induced by MeSA in human cutaneous vessels and that reported in the literature. Potential therapeutic levels were not seen below superficial muscle layers. Conclusions. Direct tissue penetration of salicylate occurs below application sites from both MeSA and TSA formulations. Tissue concentrations of MeSA were higher than predicted due to its rapid distribution in the blood.     

In vitro evaluation of UV opacity potential of <Emphasis Type="Italic">Aloe vera</Emphasis> L. gel from different germplasms

In this study, lyophilized crude and methanolic extracts of aloe gel from different germplasms (S24, RM, TN, OR, and RJN) of Aloe vera L. were tested for their ultraviolet (UV) opacity potential. UV absorption profiles, sun protection factor (SPF), and percentage blocking of UVA and UVB were considered to test UV opacity potential. Both the extracts showed UV absorption and followed the same path in the wavelength range of 250–400 nm in all the germplasms. Methanolic extract showed a stronger absorptivity than the crude lyophilized extract. Among the tested germplasms, maximum UV opacity property with a SPF of 9.97% and 79.12% UVB blocking was obtained with RJN, whereas a poor response was evident in TN with a SPF of 1.37% and 28.5% UVB blocking at 4 mg/ml methanolic extract. To our knowledge the present work for the first time documents UV opacity properties of A. vera L. gel and opens up new vistas in Aloe gel characterization.     

Comparison of in vitro and in vivo estrogenic activity of UV filters in fish.

In this work, we evaluate whether in vitro systems are good predictors for in vivo estrogenic activity in fish. We focus on UV filters being used in sunscreens and in UV stabilization of materials. First, we determined the estrogenic activity of 23 UV filters and one UV filter metabolite employing a recombinant yeast carrying the estrogen receptor of rainbow trout (rtERalpha) and made comparisons with yeast carrying the human hERalpha for receptor specificity. Benzophenone-1 (BP1), benzophenone-2 (BP2), 4,4-dihydroxybenzophenone, 4-hydroxybenzophenone, 2,4,4-trihydroxy-benzophenone, and phenylsalicylate showed full dose-response curves with maximal responses of 81-115%, whereas 3-benzylidene camphor (3BC), octylsalicylate, benzylsalicylate, benzophenone-3, and benzophenone-4 displayed lower maximal responses of 15-74%. Whereas the activity of 17beta-estradiol was lower in the rtERalpha than the hERalpha assay, the activities of UV filters were similar or relatively higher in rtERalpha, indicating different relative binding activities of both ER. Subsequently, we analyzed whether the in vitro estrogenicity of eight UV filters is also displayed in vivo in fathead minnows by the induction potential of vitellogenin after 14 days of aqueous exposure. Of the three active compounds in vivo, 3BC induced vitellogenin at lower concentrations (435 microg/l) than BP1 (4919 microg/l) and BP2 (8783 microg/l). The study shows, for the first time, estrogenic activities of UV filters in fish both in vitro and in vivo. Thus we propose that receptor-based assays should be used for in vitro screening prior to in vivo testing, leading to environmental risk assessments based on combined, complementary, and appropriate species-related assays for hormonal activity.     

盐酸西替利嗪凝胶剂的制备及体外透皮特性

目的：制备盐酸西替利嗪凝胶剂,研究其体外透皮特性。方法：以卡波姆940为辅料制备西替利嗪凝胶剂,采用改良Franz扩散池,以离体大鼠皮肤为透皮屏障,采用HPLC法测定西替利嗪的透皮行为。结果：西替利嗪凝胶体外透皮释药方程为Q=110．03t＋17．17（r=0．99）,透皮速率为110．03μg/（cm^2·h）。结论：西替利嗪凝胶具有良好的透皮效果,其体外经皮渗透符合一级动力学过程。     

Benefit and Risk of Organic Ultraviolet Filters

Modern sunscreen products provide broad-spectrum UV protection and may contain one or several UV filters. A modern UV filter should be heat and photostable, water resistant, nontoxic, and easy to formulate. Identification of a substance that meets these criteria is as difficult as discovering a new drug; hundreds of new molecules are synthesized and screened before a lead candidate is identified. The most important aspect in the development of a new UV filter is its safety. In our laboratories, the safety of new ultraviolet filters is assessed by an initial in vitro screen including photostability, cytotoxicity, photocytotoxicity, genotoxicity, and photogenotoxicity tests. These tests are performed in mammalian, yeast, and bacterial cell systems. Skin penetration potential is measured in vitro using human skin or, when required by regulations, in vivo. Because modern sunscreens are selected on the basis of their retention on and in the stratum corneum and are formulated as poorly penetrating emulsions, they generally have very low to negligible penetration rates. The safety and efficacy of UV filters are regulated and approved by national and international health authorities. Safety standards in the European Union, United States, or Japan stipulate that new filters pass a stringent toxicological safety evaluation prior to approval. The safety dossier of a new UV filter resembles that of a new drug and includes acute toxicity, irritation, sensitization, phototoxicity, photosensitization, subchronic and chronic toxicity, reproductive toxicity, genotoxicity, photogenotoxicity, carcinogenicity, and, in the United States, photocarcinogenicity testing. The margin of safety of new UV filters for application to humans is estimated by comparing the potential human systemic exposure with the no-effect level from in vivo toxicity studies. Only substances with a safe toxicological profile and a margin of safety of at least 100-fold are approved for human use. Finally, prior to marketing, new UV filters undergo stringent human testing to confirm their efficacy as well as the absence of irritation, sensitization, photoirritation, and photosensitization potential in man. UV filters not only protect against acute skin injury, such as sunburn, but also against long-term and chronic skin damage, including cellular DNA damage, photoinduced immune suppression, and, by extension, skin cancer. The protection provided by modern sunscreens against UV-induced skin cancer was shown in animal photocarcinogenicity studies and confirmed by numerous in vitro, animal, and human investigations: UV filters protect the p53 tumor suppressor gene from damage and prevent UV-induced immune suppression. Recent studies suggest that sunscreens protect against precursor lesions of skin cancer, such as actinic keratoses. Additional benefits of ultraviolet filters include prevention of photodermatoses, such as polymorphic light eruption, and, possibly, photoaging. Modern sunscreens are safe for children and adults. Percutaneous penetration and irritation rates of topically applied substances in children and adults are similar. The principal protective measure is to keep children out of the sun and/or to cover them with protective clothes; however, sunscreens are a safe and effective and often the only feasible defense of children against UV radiation. In conclusion, sunscreens are safe protective devices that undergo stringent safety and efficacy evaluation.     

Theoretical Design of Prodrug-Enhancer Combination Based on a Skin Diffusion Model: Prediction of Permeation of Acyclovir Prodrugs Treated with l-Geranylazacycloheptan-2-one

Purpose. A theoretical design of percutaneous penetration enhancement in which prodrug derivation and enhancer application are combined is proposed based on the skin diffusion model and it is experimentally verified. Methods. Employing acyclovir as a model drug, the hypothesis was tested by synthesis of its prodrugs and evaluation of their in vitro permeation in the rat skin, with or without a penetration enhancer, 1-geranylazacycloheptan-2-one(GACH). Results. Among five acyclovir prodrugs, those with higher lipophilicit-ies (propionate, butyrate, valerate, and hexanoate prodrugs) showed greater skin penetration than those of hydrophilic prodrugs (acetate), when administered in combination with GACH. Furthermore, the observed enhancement ratios were in good agreement with those predicted by theoretical consideration. Conclusions. Thus, skin permeation of prodrugs applied with an enhancer can be predicted and optimized by model analysis.     

药用库拉索芦荟活性多糖的护肤特性研究

目的 研究库拉索芦荟多糖的保湿特性、经皮吸收特性以及皮肤安全性。方法 采用超声辅助提取芦荟活性多糖,并通过人体皮肤水分含量和水分散失量测试法对所制备的芦荟活性多糖的保湿特性（包括锁水、保水两个方面）进行评价;Franz扩散池体外透皮吸收法评价其透皮吸收特性;人体斑贴试验评价其皮肤安全性。结果 与空白对照组比较,库拉索芦荟多糖可显著提高皮肤水合状态（P＜0.05）,同时降低经皮失水（P＜0.05）;多糖质量浓度为5%时,皮肤渗透速率达到0.251 0 mg/(h?cm²),24 h累计渗透量达（4.151 9±0.046 2）mg/cm²;人体皮肤斑贴试验中全部评定为0级反应。结论 库拉索芦荟活性多糖对皮肤具有显著的保湿功效以及较强的皮肤渗透力,并且高度安全,可作为优良的保湿添加剂在化妆品等肤用产品中广泛应用。     

Melatonin-based pickering emulsion for skin's photoprotection

Abstract

Context: Based on its antioxidant activity, melatonin was recently found to have a protection effect against photocarcinogenesis.

Objective: This work aimed to develop an innovative sunscreen formulation based on the Pickering emulsions concept, stabilized by physical UV filters, modified starch and natural oils associated to melatonin as a key strategy for prevention against UV-induced skin damage.

Materials and methods: For this purpose, melatonin was incorporated in Pickering emulsions that were characterized using physicochemical, in vitro and in vivo testing. Physicochemical studies included physical and chemical stability by a thorough pharmaceutical control. The possible protective effects of melatonin against UV-induced cell damage in HaCaT cell lines were investigated in vitro. The safety assessment and the in vivo biological properties of the final formulations, including Human Repeat Insult Patch Test and sunscreen water resistance tests were also evaluated.

Results and discussion: These studies demonstrated that melatonin sunscreen Pickering emulsion was beneficial and presented a powerful protection against UVB-induced damage in HaCat cells, including inhibition of apoptosis. The inclusion of zinc oxide, titanium dioxide, green coffee oil and starch ensured a high SPF (50+) against UVA and UVB.

Conclusion: The combination of melatonin, multifunctional solid particles and green coffee oil, contributed to achieve a stable, effective and innovative sunscreen with a meaningful synergistic protection against oxidative stress.     

Antibacteriophage Properties of Some Greek Plant Extracts

Abstract

The ethanol extracts (70%) of 45 plants grown in Greece were screened for antibacteriophage properties against 6 bacteriophages: coliphages T₁, T₂, T₄, T₇, φX174, and MS₂- Eight samples were found to induce a significant antiphage activity and can be used as material for further antiviral studies in vitro and in vivo.     

New flavonoid from Patrinia villosa

Context: Patrinia villosa (Thunb.) Juss (Valerianaceae) is an important ancient herbal medicine widely used for inflammation, wound healing, and abdominal pain. But little is known of the phytochemical constituents of this herbal plant.

Objective: The objective of this study is to isolate and identify the bioactive components from P. villosa.

Materials and methods: A 70% EtOH extract of P. villosa was subjected to normal-phase silica, ODS silica gel column chromatography, and semi-preparative HPLC chromatography after partitioned successively with light petroleum, dichloromethane and n-BuOH. Chemical structures of the compounds were elucidated by spectroscopic methods including UV, 1D-NMR, 2D-NMR, HR-ESI-MS, and CD spectra. The cytotoxic activity of the new component was determined with the SMMC-7721 cell line using the MTT method after incubation for 48?h.

Results: A new flavonoid named patriniaflavanone A (1) along with four known compounds was isolated from P. villosa. The four known compounds were identified as luteolin 7-O-glucuronide-6″-methyl ester (2), p-hydroxyphenylacetic acid methyl ester (3), trans-caffeic acid (4), and trans-caffeic acid methylate (5) by comparison of their spectral data with the reported data. The IC₅₀ value of patriniaflavanone A (1) on SMMC-7721 was 61.27?μM.

Discussion and conclusion: This is the first report on the isolation and identification of patriniaflavanone A (1), and compounds 2–5 were isolated for the first time from the title plant. Patriniaflavanone A (1) exhibited moderate cytotoxic activity.     

Randomized clinical trial of two anesthetic techniques for intravitreal injections: 4% liquid lidocaine on cotton swabs versus 3.5% lidocaine gel

Objective: To compare same-day and next-day pain control and safety of two anesthetic techniques utilizing 4% liquid lidocaine applied with sterile cotton swabs versus 3.5% lidocaine gel for intravitreal injections. Main outcome measures were: discomfort during anesthetic preparation and needle penetration, 1 and 24 h after injection.

Methods: Patients were randomized to alternate anesthetic method at two consecutive injections in one eye or in different eyes on the same day if requiring bilateral injections. Overall satisfaction, corneal staining, and subconjunctival hemorrhage (SCH) were compared.

Results: Fifty patients were enrolled. Both methods resulted in similar mild discomfort during anesthetic preparation, 1 and 24 h later. The gel resulted in slightly higher discomfort during needle penetration (p = 0.026). Patients were satisfied with both techniques (p = 0.91), however, 52% patients preferred gel, 33% were indifferent, and 15% preferred cotton swabs (p = 0.002). There were significantly less corneal staining (p = 0.001) and SCH (p = 0.004) after the gel.

Conclusion: Both techniques are equally effective and yield mild discomfort scores during the procedure and the next day. The gel method results in significantly less ocular surface irritation.     

Efficacy of different photoprotection strategies in preventing actinic keratosis new lesions after photodynamic therapy. The ATHENA study: a two-center,randomized, prospective,assessor-blinded pragmatic trial

Background: Treatment of actinic keratosis (AK) and field cancerization with photodynamic therapy (PDT) is an effective therapeutic approach with a significant reduction in the number of AK lesions (–75% or more) associated with a significant cosmetic improvement of the photodamaged skin. Recently, also, the daylight PDT (DL-PDT) has proven to be as effective as the conventional PDT (C-PDT), but with a better tolerability. After C-PDT and DL-PDT it is advised to use photoprotection strategies to improve the clinical evolution and prevent the appearance of new AK lesions that usually appear 3–6 months after the last phototherapy session. However, there are no robust clinical data regarding the type of photoprotection to be used (SPF level, duration of treatment, etc.) after successful PDT.

Study aim: The present study (ATHENA trial) evaluated the efficacy and tolerability of a topical product based on 0.8% piroxicam and 50+ solar filters (ACTX), applied twice a day as sequential therapy after C-PDT or DL-PDT on the evolution of AK lesions number compared to the use of very high photoprotection products commonly used in this clinical setting (SPF50+ or SPF100+ associated with photolyase) (Standard Sunscreens: SS group). Subjects and methods: This was a multicenter, randomized, two-arm, prospective controlled, assessor-masked outcome evaluation, parallel group (1:1), pragmatic study of 6 months duration in patients with multiple AK lesions suitable for photodynamic therapy. The objectives of the study were the evaluation of the evolution of the number of AK lesions during the period of treatment/application of the study products, and the Investigator global clinical assessment score (IGA score; 4: marked improvement, 3: good, 2: moderate; 1 no improvement; 0: worsening) 2, 3, and 6 months after the last PDT session. A total of 68 subjects (50 men, 18 women; mean age 70 years), 34 assigned to treatment with ACTX and 34 to treatment with SS (17 treated with a SPF50+ and 17 with a photolyase-containing SPF100+ products), were enrolled in the study.

Results: The number of AK lesions present before C-PDT/DL-PDT was 11.8?±?5.8 in the ACTX group and 12.4?±?6.9 in the SS group. In both groups, there was a progressive reduction of AK lesions observed at baseline (–86% and –87% after 2 months and –88% and –83% at month 3 in ACTX and in the SS group, respectively). At month 6, AK mean lesion number was 1.8?±?1.6 in the ACTX and 3.2?±?2.3 in the SS group; this difference was statistically significant (p?=?0.03). The IGA score at the end of the study was 3.2 in the ACTX and 2.7 in the SS group (p?=?0.05). The percentage of subjects with an IGA score of 4/3 (very good or good) was 81% in the ACTX and 55% in the SS group (p?=?0.06).

Conclusion: In subjects with AK treated with C-PDT or DL-PDT, a “medicalized” photoprotection treatment is associated with a favorable clinical outcome with progressive reduction of lesions. In contrast to a very high photoprotection (SPF50+ or SPF100+/photolyase), the use of piroxicam 0.8%/SPF 50+ is associated with a significantly greater improvement in clinical evolution of AK lesions.     

Effects of Sucrose Oleate and Sucrose Laureate on in Vivo Human Stratum Corneum Permeability

Purpose. The purpose of this work was to 1) investigate the effect of sucrose esters (sucrose oleate and sucrose laureate in water or in Transcutol®, TC) on the stratum corneum (SC) barrier properties in vivo and 2) examine the impact of these surfactant-like molecules on the in vivo percutaneous penetration of a model penetrant 4-hydroxybenzonitrile (4-HB). Methods. Attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and transepidermal water loss measurements were used to evaluate the sucrose oleate- and sucrose laureate-induced biophysical changes in SC barrier function in vivo. In addition, the effect of the enhancers on 4-HB penetration was monitored in vivo using ATR-FTIR spectroscopy in conjunction with tape-stripping of the treated site. Results. Treatment of the skin with 2% sucrose laureate or sucrose oleate in TC significantly increased the extent of 4-HB penetration relative to the control. Furthermore, when skin treated with these formulations was examined spectroscopically, the C-H asymmetric and symmetric stretching bands of the lipid methylene groups were characterized by 1) decreased absorbances and 2) frequency shifts to higher wavenumbers. These effects on the SC lipids and 4-HB penetration were more pronounced for sucrose laureate when combined with TC. Conclusions. A combination of sucrose esters (oleate or laureate) and TC is able to temporally alter the stratum corneum barrier properties, thereby promoting 4-HB penetration. These molecules are worthy of further investigation as potential candidates for inclusion in transdermal formulations as penetration enhancers.