Cutaneous Pharmacokinetics of Acyclovir Cream 5% Products: Evaluating Bioequivalence with an In Vitro Permeation Test and an Adaptation of Scaled Average Bioequivalence.

PURPOSE: The in vitro permeation test (IVPT) with a new statistical approach was investigated to evaluate the utility of an IVPT methodology as a sensitive tool to support a demonstration of bioequivalence (BE) for topical dermatological drug products. METHODS: IVPT experiments were performed utilizing ex vivo human skin. The initial screening tests involved four differently formulated acyclovir 5% creams: the U.S. Zovirax® as the reference product and the U.K. Zovirax®, Aciclovir 1A Pharma® and Aciclostad® as test products. Subsequently, a pivotal BE study was conducted comparing the two Zovirax® creams. The resulting data was used to evaluate BE of test (T) versus reference (R), T versus T, and R versus R, with an adaption of scaled average BE approach to address high variability in IVPT data. RESULTS: More acyclovir permeated into and through the skin from the two Zovirax® creams compared to the two non-Zovirax® creams. The U.S. Zovirax® cream showed a significantly higher Jmax and total amount permeated over 48 h, compared to the U.K. Zovirax® cream. The statistical analysis indicated that the test and reference products were not bioequivalent, whereas each product tested against itself was shown to be bioequivalent. CONCLUSIONS: The current study demonstrated that the IVPT method, with an appropriate statistical analysis of the results, is a sensitive and discriminating test that can detect differences in the rate and extent of acyclovir bioavailability in the skin from differently formulated cream products.

Roflumilast Cream Improves Signs and Symptoms of Plaque Psoriasis: Results from a Phase 1/2a Randomized, Controlled Study.

Background: Roflumilast cream (ARQ-151) is a highly potent, selective phosphodiesterase-4 inhibitor in development for once-daily topical treatment of chronic plaque psoriasis. Objectives: To assess the safety and efficacy of once-daily roflumilast cream 0.5% and 0.15% in patients with chronic plaque psoriasis. Methods: This phase 1/2a study enrolled a single-dose, open-label cohort (Cohort 1: 0.5% cream applied to 25 cm² psoriatic plaques), and a 28-day, double-blinded cohort (Cohort 2: 1:1:1 randomization to roflumilast cream 0.5%, 0.15%, or vehicle). Patients had chronic plaque psoriasis of >6 months' duration with ≤5% body surface area involvement. Outcomes included safety (adverse events) and efficacy (percentage change in the Target Plaque Severity Score [TPSS] × Target Plaque Area [TPA]) at week 4. Results: For Cohorts 1 (n=8) and 2 (n=89), adverse events (all mild/moderate; none severe or serious) were similar between active arms and vehicle. Treatment-related events were confined to the application site, without differences between drug and vehicle. No patient discontinued treatment due to adverse events. The primary efficacy endpoint was met for both roflumilast cream doses: TPSS×TPA improvement at week 4 was statistically significant for roflumilast 0.5% (P=0.0007) and 0.15% (P=0.0011) versus vehicle; significance was reached as early as 2 weeks. For both roflumilast cream doses, 66%-67% improvement from baseline was observed at week 4, without reaching a plateau, versus 38% improvement for vehicle. Conclusion: Roflumilast cream was safe and highly effective at doses of 0.5% and 0.15% and represents a potential novel once-daily topical therapy for the treatment of chronic plaque psoriasis. ClinicalTrials.gov NCT03392168. J Drugs Dermatol. 2020;19(8): doi:10.36849/JDD.2020.5370.

Stratum Corneum Sampling to Assess Bioequivalence between Topical Acyclovir Products.

PURPOSE: To examine the potential of stratum corneum (SC) sampling via tape-stripping in humans to assess bioequivalence of topical acyclovir drug products, and to explore the potential value of alternative metrics of local skin bioavailability calculable from SC sampling experiments. METHODS: Three acyclovir creams were considered in two separate studies in which drug amounts in the SC after uptake and clearance periods were measured and used to assess bioequivalence. In each study, a "reference" formulation (evaluated twice) was compared to the "test" in 10 subjects. Each application site was replicated to achieve greater statistical power with fewer volunteers. RESULTS: SC sampling revealed similarities and differences between products consistent with results from other surrogate bioequivalence measures, including dermal open-flow microperfusion experiments. Further analysis of the tape-stripping data permitted acyclovir flux into the viable skin to be deduced and drug concentration in that 'compartment' to be estimated. CONCLUSIONS: Acyclovir quantities determined in the SC, following a single-time point uptake and clearance protocol, can be judiciously used both to objectively compare product performance in vivo and to assess delivery of the active into skin tissue below the barrier, thereby permitting local concentrations at or near to the site of action to be determined.

Proderm technology: a water- based lipid delivery system for dermatitis that penetrates viable epidermis and has antibacterial effects.

BACKGROUND: A defective skin barrier and bacterial colonization are two important factors in maintenance and progression of atopic dermatitis and chronic allergic/irritant hand dermatitis. A water-based lipid delivery system containing physiologic lipids was previously shown to be a useful adjunct in the treatment of hand dermatitis. We tested the ability of this formulation to penetrate into the viable epidermis and in addition assessed its antibacterial properties. METHODS: Epidermal penetration of the product was assessed by fluorescence microscopy. Recovery of Escherichia coli and Staphylococcus aureus MRSA from skin treated with Neosalus® foam was quantified. RESULTS: Components of Neosalus® penetrated the stratum corneum and were distributed throughout the viable epidermis. Neosalus® significantly decreased recovery of both Staphylococcus aureus and Escherichia coli from the skin surface. CONCLUSIONS: The ability of components of Neosalus® to be taken up into the viable epidermis and potentially made available for incorporation into the barrier lipids, combined with antibacterial properties, indicate that this formulation may be valuable not only in chronic hand dermatitis, but also in various other forms of dermatitis. TRIAL REGISTRATION: Current Controlled Trials ISRCTN18191379 , 28/12/2018, retrospectively registered.

Pharmacokinetic Profile, Safety, and Tolerability of Clascoterone (Cortexolone 17-alpha propionate, CB-03-01) Topical Cream, 1% in Subjects With Acne Vulgaris: An Open-Label Phase 2a Study

Clascoterone (cortexolone 17α-propionate, CB-03-01) 1% cream, a topical, androgen receptor (AR) inhibitor under investigation for the treatment of acne vulgaris, is rapidly metabolized to cortexolone in human plasma. The primary objectives of this study were to determine the pharmacokinetic (PK) properties and adrenal suppression potential of clascoterone topical cream, 1% in subjects with acne vulgaris. Study Design: This study was an open-label, multicenter study in 42 subjects ≥12 years of age with moderate-to-severe acne (Grade 3-4 on the Investigator's Global Assessment [IGA]), on the face, chest and/or back. Cohort 1(>18 years of age) and Cohort 2 (12-18 years of age) applied clascoterone topical cream, 1% twice daily (BID) for 14 days. Primary safety endpoints included hypothalamic-pituitary-adrenal (HPA) axis response to cosyntropin via a Cosyntropin Stimulation Test (CST) upon screening (day 1) and at day 14 (HPA axis suppression was defined as a post-stimulation serum cortisol level <18 µg/dL at day 14); and PK evaluation including concentration-time profiles of clascoterone and cortexolone in plasma­PK parameters were determined using "non-compartmental" analysis. Secondary safety endpoints included clinical laboratory testing, local and systemic adverse events (AEs), physical examination/vital signs, and electrocardiogram (ECG). Results: 42 subjects (Cohort 1=20, Cohort 2= 22) enrolled. Cohort 1 was comprised of 15 females (15/20, 75%) and 5 males (5/20, 25%), non-Hispanic/Latino (20/20, 100%), mean age is 24.4 years. Cohort 2 was comprised of 12 females (12/22, 54.5%) and 10 males (10/22, 45.5%), non-Hispanic/Latino (21/22, 95.5%), and mean age is 15.6 years. Three subjects (3/42,7%), 1 adult and 2 adolescents, demonstrated an abnormal HPA axis response with post-stimulation serum cortisol levels ranging from 14.9 to 17.7 µg/dL at day 14. All returned to normal HPA axis function, four weeks after day 14. None showed clinical evidence of adrenal suppression. Clascoterone plasma concentrations achieved PK steady-state by day 5. Clascoterone systemic exposure was similar between both cohorts. At steady-state, plasma concentrations increased ~1.8 to 2.1 fold versus first dose with mean (coefficient of variation [CV] %) maximum plasma concentrations of 4.4 ng/mL (67%) and 4.6 ng/mL (103%) in Cohort 1 and Cohort 2, respectively. Cortexolone plasma concentrations trended below the lower limit of quantitation (0.5 ng/mL) in both cohorts. Local skin reactions (LSRs) were mostly mild, with only one moderate case of pruritus. There were nine AEs categorized as follows: definitely related (N=2), probably related (N=4), unlikely/not related (N=3), to clascoterone. Conclusion: This study demonstrates the safety and tolerability of clascoterone topical cream, 1% in adolescents and adults with acne vulgaris treated BID for 14 consecutive days. J Drugs Dermatol. 2019;18(6):563-568.

Influence of omega fatty acids on skin permeation of a coenzyme Q10 nanoemulsion cream formulation: characterization, in silico and ex vivo determination.

Objective: The aim of this study was to develop a coenzyme Q10 nanoemulsion cream, characterize and to determine the influence of omega fatty acids on the delivery of coenzyme Q10 across model skin membrane via ex vivo and in silico techniques. Methods: Coenzyme Q10 nanoemulsion creams were prepared using natural edible oils such as linseed, evening primrose, and olive oil. Their mechanical features and ability to deliver CoQ10 across rat skin were characterized. Computational docking analysis was performed for in silico evaluation of CoQ10 and omega fatty acid interactions. Results: Linseed, evening primrose, and olive oils each produced nano-sized emulsion creams (343.93-409.86 nm) and exhibited excellent rheological features. The computerized docking studies showed favorable interactions between CoQ10 and omega fatty acids that could improve skin permeation. The three edible-oil nanoemulsion creams displayed higher ex vivo skin permeation and drug flux compared to the liquid-paraffin control cream. The linseed oil formulation displayed the highest skin permeation (3.97 ± 0.91 mg/cm2) and drug flux (0.19 ± 0.05 mg/cm2/h). Conclusion: CoQ10 loaded-linseed oil nanoemulsion cream displayed the highest skin permeation. The highest permeation showed by linseed oil nanoemulsion cream may be due to the presence of omega-3, -6, and -9 fatty acids which might serve as permeation enhancers. This indicated that the edible oil nanoemulsion creams have potential as drug vehicles that enhance CoQ10 delivery across skin.

In situ biodistribution and residency of a topical anti-inflammatory using fluorescence lifetime imaging microscopy.

BACKGROUND: GSK2894512 is a topically delivered investigational drug being developed for treatment of atopic dermatitis and psoriasis. OBJECTIVES: To investigate, in a phase I clinical trial, the spatial biodistribution and residency of GSK2894512 within the epidermis and dermis of healthy human participants noninvasively using fluorescence lifetime imaging microscopy (FLIM). METHODS: Two topical drug formulations containing GSK2894512 1% were applied to the right and left forearms of six participants for seven consecutive days, followed by seven days of observation for residency. FLIM images were obtained daily throughout the study, approximately every 24 h. During the treatment phase of the study, images were collected from each participant pretreatment, reflecting the residual dose from the previous day. Three punch biopsies from each participant of one formulation was obtained from the treated region during the post-treatment follow-up period between days 8 and 14 for comparison with FLIM results. RESULTS: Cellular and subcellular features associated with different epidermal and dermal layers were visualized noninvasively, down to a depth of 200 µm. Results yielded three-dimensional maps of GSK2894512 spatial distribution and residency over time. This fluorescence data provided a marker that was used as a monitor for day-to-day variance of drug presence and residency postapplication. CONCLUSIONS: The results suggest FLIM could be a viable alternative to skin biopsies without the usual patient discomfort and limitations, thereby enabling the direct measurement of skin distribution through longitudinal monitoring. These results are the first step in establishing the unique capabilities that multiphoton imaging could provide to patients through noninvasive drug detection.

Fluorouracil-Loaded Gold Nanoparticles for the Treatment of Skin Cancer: Development, in Vitro Characterization, and in Vivo Evaluation in a Mouse Skin Cancer Xenograft Model.

Fluorouracil (5-FU) is an antimetabolite drug used in the treatment of various malignancies, such as colon and skin cancers. However, its systemic administration results in severe side effects. Topical 5-FU delivery for the treatment of skin cancer could circumvent these shortcomings, but it is limited by the drug poor permeability through the skin. To enhance 5-FU efficacy against skin cancer and reduce its systemic side effects, it was loaded into a gold nanoparticle (GNP)-based topical delivery system. 5-FU was loaded onto GNPs capped with CTAB through ionic interactions between 5-FU and CTAB. GNPs were prepared at different 5-FU/CTAB molar ratios and evaluated using different techniques. GNP stability and drug release were studied as a function of salt concentration and solution pH. Optimum 5-FU/CTAB-GNPs were incorporated into gel and cream bases, and their ex vivo permeability was evaluated in mice dorsal skin. The in vivo anticancer efficacy of the same preparations was evaluated in A431 tumor-bearing mice. The GNPs had spherical shape and a size of ∼16-150 nm. Maximum 5-FU entrapment was achieved at 5-FU/CTAB molar ratio of 1:1 and pH 11.5. Drug release from GNPs was sustained and pH-dependent. 5-FU GNP gel and cream had around 2-fold higher permeability through mice skin compared with free 5-FU gel and cream formulations. Further, in vivo studies in a mouse model having A431 skin cancer cells implanted in the subcutaneous space showed that the GNP gel and cream achieved 6.8- and 18.4-fold lower tumor volume compared with the untreated control, respectively. These results confirm the potential of topical 5-FU/CTAB-GNPs to enhance drug efficacy against skin cancer.

Sunscreen creams containing naringenin nanoparticles: Formulation development and in vitro and in vivo evaluations.

BACKGROUND: The aim of this study was to develop sunscreen creams containing polymeric nanoparticles (NPs) of naringenin for photoprotective and antioxidant effects. METHODS: Polymeric NPs of naringenin were prepared and optimized. The NPs were incorporated into sunscreen creams and evaluated for in vitro and in vivo skin retention. RESULTS: The optimized naringenin NPs showed a size of 131.2 nm, zeta potential -25.4 mV, and entrapment efficiency 32.45%. The absence of drug-excipient interaction was confirmed by Fourier transform infrared spectroscopy and differential scanning calorimetry. X-Ray diffraction analysis demonstrated the amorphization of naringenin in nanoparticles. Transmission electron microscopy showed the sphericity of the NPs with the size of <200 nm. Cytotoxicity assessment in HaCaT cells indicated non-toxic nature of naringenin NPs. In vitro skin permeation studies demonstrated that higher amount of naringenin permeated at the end of 12 hours (Q12 hours  = 184.03 ± 3.37 µg/cm2 ) and deposited in the skin (10.38 ± 0.48 µg/cm2 ) from NPs as compared to plain naringenin. Sunscreen creams (SC1-SC5) containing plain naringenin or NPs with/without nano-zinc oxide and nano-titanium dioxide were prepared and evaluated. Optimized cream (SC5) containing naringenin NPs showed highest SPF value and enhanced skin retention of naringenin in comparison with NPs in suspension form and other cream formulations. CONCLUSION: Optimized nanoparticulate sunscreen cream exhibited highest skin retention and negligible skin permeation of naringenin besides showing excellent SPF value.

Application of an Optimized Tape Stripping Method for the Bioequivalence Assessment of Topical Acyclovir Creams.

This study indicates the application of tape stripping (TS) for bioequivalence (BE) assessment of a topical cream product containing 5% acyclovir. A TS method, previously used successfully to assess BE of topical clobetasol propionate and clotrimazole formulations, was used to assess BE of an acyclovir cream (5%) formulation as well as a diluted acyclovir formulation (1.5%) applied to the skin of healthy humans. An appropriate application time was established by conducting a dose duration study using the innovator product, Zovirax® cream. Transepidermal water loss was measured and used to normalize thicknesses between subjects. The area under the curve (AUC) from a plot of amount of acyclovir/strip vs cumulative fraction of stratum corneum (SC) removed was calculated for each application site. BE was assessed using Fieller's theorem in accordance with FDA's guidance for assessment of BE of topical corticosteroids. Adco-acyclovir cream (5%) was found to be BE to Zovirax® cream, where the mean test/reference (T/R) ratio of the AUC's was 0.96 and the bioequivalence interval using a 90% confidence interval was 0.91-1.01 with a statistical power > 95%, whereas the diluted test product fell outside the BE acceptance criteria with T/R ratio of AUC of 0.23 and a 90% CI of 0.20-0.26. This study indicates that the data resulting from the application of this TS procedure has reinforced the potential for its use to assess BE of topical drug products intended for local action, thereby obviating the necessity to undertake clinical trials in patients.

Utility of Göttingen minipigs for Prediction of Human Pharmacokinetic Profiles After Dermal Drug Application.

PURPOSE: Although Göttingen minipigs have been widely used for the evaluation of skin absorption, the correlation of minipig skin permeability with human skin absorption remains unclear. This study was designed to investigate the prediction of human plasma concentrations after dermal application of drug products using skin permeability data obtained from minipigs. METHODS: First, in vitro skin permeabilities of seven marketed transdermal drug products were evaluated in minipigs, and compared with in vitro human skin permeability data. Next, plasma concentration-time profiles in humans after dermal applications were simulated using the in vitro minipig skin permeability data. Finally, the in vitro-in vivo correlation of minipig skin permeability was assessed. RESULTS: The in vitro skin permeabilities in minipigs were correlated strongly with in vitro human skin permeability data for the same drug products, indicating the utility of minipig skin as an alternative to human skin for in vitro studies. The steady-state plasma concentration or the maximum concentration of drugs was within 2-fold of the clinical data. Bioavailability was approximately 3-fold lower than in vitro permeated fraction. CONCLUSIONS: Predictions using in vitro skin permeability data in Göttingen minipig skin can reproduce the human pharmacokinetic profile, although the prediction of in vivo skin absorption underestimates human absorption.

Ex vivo human skin permeation of methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI).

Methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) are biocides used in many types of products such as cosmetics, paints, and cleaning agents. Skin contact is often encountered when using these products. Although MCI and MI are strong allergens and cause skin irritation, no scientific skin permeation study has been reported except for some unpublished data. Therefore, this study assessed the permeation of MCI and MI both separately and as a mixture through freshly dermatomed human skin (800 µm) in a flow-through diffusion cell system. Different concentrations of aqueous standards (1.5/1, 70/50, 150/35, and 750/175 µg/mL of MCI/MI) and various commercial products were assessed after 15-20 h of exposure. In parallel, the dose-dependent irritant effects of MCI/MI and MI were estimated by histology following 6- or 24-h exposure. Overall results show that MI in formulations or in aqueous standard solutions quickly permeated the skin with time lags less than 15 min while MCI was much slower (>3.5 h). MCI in formulations had permeation rates up to five times greater than that for MI in the same product, and in two tested creams were not found to permeate skin. Some signs of irritation were observed by histology; especially at the highest MCI/MI concentrations (750/250 µg/mL) in aqueous solutions. This confirms that MCI reacts readily with skin and may induce local irritation. The MCI and MI permeations are also greatly influenced by the topical vehicle. It is, therefore, more relevant to test exposures to formulations than aqueous standard solutions.

Development of a Topical Resveratrol Formulation for Commercial Applications Using Dendrimer Nanotechnology.

Resveratrol (RSV) is well known for its anti-oxidant and anti-aging properties. However, resveratrol is insoluble in water and has stability issues. Recently, efforts were placed to prepare a resveratrol-based advanced anti-aging topical product but it contains harsh organic solvents and oils that could be harmful to the human body and the environment. Hence, we propose the use of a multifunctional dendrimer to solve the solubility and stability issues of resveratrol. A dendrimer-resveratrol complex was prepared, optimized and tested for solubility enhancement, stability in solution and cream dosage forms. We have also developed a high performance liquid chromatography method to measure the resveratrol within the final product. PAMAM dendrimers increased the solubility and stability of resveratrol in water and semisolid dosage forms. Therefore, this product would be water based 'green' formulation devoid of harsh organic solvents and oils and can be safely applied to the skin. Additionally, we have shown that the dendrimer helped to increase overall RSV loading and skin penetration of resveratrol. The dendrimer-RSV formulation was successfully scaled up towards commercialization. Dendrimer with RSV has led to an innovation in anti-aging cream and solutions that could be commercially marketed. Dendrimer-RSV complex could also be added to other product forms for additional purposes and applications.

Exposure Factor considerations for safety evaluation of modern disposable diapers.

Modern disposable diapers are complex products and ubiquitous globally. A robust safety assessment for disposable diapers include two important exposure parameters, i) frequency of diaper use & ii) constituent transfer from diaper to skin from direct and indirect skin contact materials. This article uses published information and original studies to quantify the exposure parameters for diapers. Using growth tables for the first three years of diapered life, an average body weight of 10-11 kg can be calculated, with a 10th percentile for females (8.5-8.8 kg). Data from surveys and diary studies were conducted to determine the frequency of use of diapers. The overall mean in the US is 4.7 diapers per day with a 75th, 90th, and 95th percentile of 5.0, 6.0, and 7.0 respectively. Using diaper topsheet-lotion transfer as a model, direct transfer to skin from the topsheet was 3.0-4.3% of the starting amount of lotion. Indirect transfer of diaper core materials as a measure of re-wetting of the skin via urine resurfacing back to the topsheet under pressure was estimated at a range of 0.32-0.66% averaging 0.46%. As described, a thorough data-based understanding of exposure is critical for a robust exposure based safety assessment of disposable diapers.

Ex vivo Cutaneous Bioavailability of Topical Mometasone Furoate in an O/W Preparation.

Mometasone furoate (MMF) is a modern glucocorticoid of the 4th generation, which has been proven not only for inhalation but also for cutaneous treatment. Due to its lipophilic character, it is mainly used in ointments and creams with an outer lipophilic phase (W/O type). However, this study investigated the cutaneous cytotoxicology of MMF and tried to characterize its pharmacokinetic effects on the skin using an O/W preparation. An HPLC method has been developed and validated for the detection of MMF in cutaneous tissue, and concentration-time curves of MMF were created after cutaneous application on unaffected as well as lesional skin. Cytotoxicological characterization was carried out using scratch assays on keratinocytes and cutaneous fibroblasts. Results showed that the condition of the skin had no significant impact on the cutaneous bioavailability of MMF, but the intrinsic effect of the O/W vehicle could be utilized in periods of acute inflammation. Cytotoxicological data gave no new indications regarding the safety of MMF.

Lamellar Liquid Crystal Improves the Skin Retention of 3-O-Ethyl-Ascorbic Acid and Potassium 4-Methoxysalicylate In Vitro and In Vivo for Topical Preparation.

The study aimed at increasing the skin retention of 3-O-ethyl-ascorbic acid (EA) and potassium 4-methoxysalicylate (4-MSK) via topical administration for effective skin-whitening. To achieve this goal, EA and 4-MSK were formulated into lamellar liquid crystalline (LLC) cream, and response surface methodology (RSM) was employed to optimize the formulation. Polarized light microscopy (PLM), differential scanning calorimetry (DSC), and rheological experiments were performed to confirm the presence of the LLC structure in the base of cream. In addition, a comparison analysis of the skin retention of the two drugs between the LLC cream and the common o/w (COW) cream was made through in vitro permeation and in vivo drug distribution experiments. As a result, the optimal formulation was defined as 1.2% of EA, 1.48% of 4-MSK, 14.05% of Schercemol™ DISM Ester (DISM) as the oil, 4.0% of Emulium® Delta as the emulsifier, and 3.0% of stearyl alcohol as the co-emulsifier. In comparison with the COW cream, the LLC cream significantly increased the skin retention of EA and 4-MSK both in vitro and in vivo. In conclusion, the LLC carrier serves as a promising choice for topical preparation by enhancing skin retention and providing desirable rheological characteristics.

Development and Evaluation of a Novel Delivery System Containing Phytophospholipid Complex for Skin Aging.

Citrus auranticum and Glycyrrhiza glabra are rich in anti-oxidant polyphenols helpful in prevention of skin aging. Polyphenols have high polarity and lower skin penetration resulting in lower cutaneous delivery. The present work is attempted to develop a novel polyherbal phospholipid complex cream to improve cutaneous delivery of polyphenols for sustained anti-oxidant action. Phytochemical and in vitro anti-oxidant evaluation was done on methanolic extracts of orange peel and liquorice powder. Total phenolic content, total flavonoid content, and anti-oxidant assays were done on different ratios of orange peel and liquorice extract. Ratio 1:2 gave highest total phenolic content (TPC) (530.00 ± 1.56 mg gallic acid equivalent (GAE) g(-1) extract), total flavonoid content (TFC) (246.25 ± 1.03 mg rutin equivalent (RUE) g(-1) extract), 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activity (87.99 ± 0.64%), and H2O2 scavenging activity (72.47 ± 0.86%) and hence was used for formulation. Solvent evaporation method using methanol with 1:1 extract to phospholipid ratio was found to have entrapment efficiency of 93.22 ± 0.26%. Evaluation parameters like scanning electron microscopy (SEM), Fourier transform infrared spectrophotometry (FT-IR), and differential scanning calorimetry (DSC) confirmed formation of complex. The complex was formulated as oil-in-water cream and evaluated for various parameters. The optimized cream containing 1% complex was non-irritant and was found to be stable for 3-month period under conditions of stability study. Ex vivo diffusion studies showed that extract phospholipid complex cream had better retention of polyphenols in the skin when compared to conventional extract cream giving prolonged and stronger topical action. The cream had an anti-elastase activity of 28.02 ± 0.95% at concentration of 3000 µg ml(-1) (w/v). Thus, the developed safe and stable polyherbal phytophospholipid complex cream exhibited good potential as anti-aging cosmeceutical.

In vivo evaluation of two forms of urea in the skin by Raman spectroscopy after application of urea-containing cream.

BACKGROUND/PURPOSE: As urea is one of the natural moisturizing factor (NMF) components in the stratum corneum, it has been used in topical products to improve skin conditions. However, the penetration behavior of urea in the skin after application of urea-containing cream has not been determined as there has been no technique with which to measure the urea content in the skin in vivo non-invasively. We therefore applied Raman spectroscopy to evaluate the depth profile of urea content in the skin. We investigated changes in depth profiles of two forms of urea to evaluate the penetration behavior of urea after application of urea-containing cream. METHODS: Commercially available moisturizing creams F and R in quantities of 2.2-mg/cm(2) and containing 20% (w/w) urea were applied to volar forearm skin of six Japanese subjects. Raman spectra of the skin were measured at 2-µm intervals from the skin surface toward the interior using a confocal Raman spectrometer (model 3510 SCA) before and 15, 60, and 120 min after the application of the creams. The amounts of the two forms of urea, urea in water solution and urea in a solid state, were calculated by adding the spectra of solid urea and the cream base to a previously reported algorithm including the spectrum of urea in water solution. RESULTS: The characteristic band of urea in water solution was observed at approximately 1004/cm and that of the solid state at approximately 1010/cm in the Raman spectra of the skin after application of either cream. There was more urea in water solution form in the area where cream F was applied than in the area where cream R was applied. There was more urea in a solid state in the area where cream R was applied than in the area where cream F was applied at all depths and measurement times. In particular, there was significantly more urea in a solid state below a depth of 2 µm in the area where cream R was applied than in the area where cream F was applied 15 min after application. CONCLUSION: The present study demonstrated that we can measure both urea forms in the skin after the application of urea-containing creams. The proposed technique would be useful in the evaluation of characteristics of the penetration behavior of urea in the skin after the application of various urea-containing moisturizers.

Increased bioavailability of hydrocortisone dissolved in a cream base.

BACKGROUND/OBJECTIVES: The aim of this study was to compare vasoconstrictor activity and, by inference, the clinical anti-inflammatory effectiveness of hydrocortisone in two different formulations: 1% dissolved hydrocortisone cream and 1% dispersed hydrocortisone cream. Moisturising capacity and safety were also determined. METHODS: Both topical preparations were applied without occlusion on forearms twice daily for 5 days. An assessment of vasoconstriction was performed in a double-blinded manner pretreatment and then thrice daily for 6 days and once 7 days post-application, using an objective rating scale. For the dissolved preparation only, moisturising capacity was determined by measurement of transepidermal water loss (TEWL) at 0, 2, 4, 6 and 24 h, and also by the measurement of water content at 0 and 24 h. Safety was assessed by repeat insult patch tests (RIPT). RESULTS: In all, 10 volunteers completed the vasoconstrictor and moisturising studies, while 52 completed the RIPT. For 1% dissolved hydrocortisone cream and 1% dispersed hydrocortisone cream, respectively, areas under the blanching curves were 1240 and 295; total scores were 129.0 and 31.5; summed % total possible scores were 161.3 and 39.4; Tm/10 mean values were 3.47 and 1.64. The 1% dissolved hydrocortisone cream was found to be statistically more potent than the 1% dispersed hydrocortisone cream. Furthermore, the 1% dissolved hydrocortisone cream was found to be moisturising compared to no treatment. No adverse events were observed. CONCLUSIONS: A cream containing 1% dissolved hydrocortisone exhibits greater vasoconstrictor activity than a cream containing 1% dispersed hydrocortisone.

The impact of manufacturing variables on in vitro release of clobetasol 17-propionate from pilot scale cream formulations.

OBJECTIVES: The purpose of the study was to evaluate the effect of different homogenization speeds and times, anchor speeds and cooling times on the viscosity and cumulative % clobetasol 17-propionate released per unit area at 72 h from pilot scale cream formulations. A 2(4) full factorial central composite design for four independent variables were investigated. MATERIALS AND METHODS: Thirty pilot scale batches of cream formulations were manufactured using a Wintech® cream/ointment plant. The viscosity and in vitro release of CP were monitored and compared to an innovator product that is commercially available on the South African market, namely, Dermovate® cream. RESULTS AND DISCUSSION: Contour and three-dimensional response surface plots were produced and the viscosity and cumulative % CP released per unit area at 72 h were found to be primarily dependent on the homogenization and anchor speeds. An increase in the homogenization and anchor speeds appeared to exhibit a synergistic effect on the resultant viscosity of the cream whereas an antagonistic effect was observed for the in vitro release of CP from the experimental cream formulations. The in vitro release profiles were best fitted to a Higuchi model and diffusion proved to be the dominant mechanism of drug release that was confirmed by use of the Korsmeyer-Peppas model. CONCLUSION: The research was further validated and confirmed by the high prognostic ability of response surface methodology (RSM) with a resultant mean percentage error of (±SD) 0.17 ± 0.093 suggesting that RSM may be an efficient tool for the development and optimization of topical formulations.