Biodegradable calcium carbonate carriers for the topical delivery of clobetasol propionate

Inflammatory dermatoses represent a global problem with increasing prevalence and recurrence among the world population. Topical glucocorticoids (GCs) are the most commonly used anti-inflammatory drugs in dermatology due to a wide range of their therapeutic actions, which, however, have numerous local and systemic side effects. Hence, there is a growing need to create new delivery systems for GCs, ensuring the drug localization in the pathological site, thus increasing the effectiveness of therapy and lowering the risk of side effects. Here, we propose a novel topical particulate formulation for the GC clobetasol propionate (CP), based on the use of porous calcium carbonate (CaCO3) carriers in the vaterite crystalline form. The designed carriers contain a substantially higher CP amount than conventional dosage forms used in clinics (4.5% w/w vs. 0.05% w/w) and displayed a good biocompatibility and effective cellular uptake when studied in fibroblasts in vitro. Hair follicles represent an important reservoir for the GC accumulation in skin and house the targets for its action. In this study, we demonstrated successful delivery of the CP-loaded carriers (CP-CaCO3) into the hair follicles of rats in vivo using optical coherent tomography (OCT). Importantly, the OCT monitoring revealed the gradual intrafollicular degradation of the carriers within 168 h with the most abundant follicle filling occurring within the first 48 h. Biodegradability makes the proposed system especially promising when searching for new CP formulations with improved safety and release profile. Our findings evidenced the great potential of the CaCO3 carriers in improving the dermal bioavailability of this poorly water-soluble GC.

Clobetasol Propionate Is a Heme-Mediated Selective Inhibitor of Human Cytochrome P450 3A5

The human cytochrome P450 (CYP) enzymes CYP3A4 and CYP3A5 metabolize most drugs and have high similarities in their structure and substrate preference. Whereas CYP3A4 is predominantly expressed in the liver, CYP3A5 is upregulated in cancer, contributing to drug resistance. Selective inhibitors of CYP3A5 are, therefore, critical to validating it as a therapeutic target. Here we report clobetasol propionate (clobetasol) as a potent and selective CYP3A5 inhibitor identified by high-throughput screening using enzymatic and cell-based assays. Molecular dynamics simulations suggest a close proximity of clobetasol to the heme in CYP3A5 but not in CYP3A4. UV-visible spectroscopy and electron paramagnetic resonance analyses confirmed the formation of an inhibitory type I heme-clobetasol complex in CYP3A5 but not in CYP3A4, thus explaining the CYP3A5 selectivity of clobetasol. Our results provide a structural basis for selective CYP3A5 inhibition, along with mechanistic insights, and highlight clobetasol as an important chemical tool for target validation.

Rapid Onset of Action in Patients With Moderate-to-Severe Plaque Psoriasis With Halobetasol 0.01%/Tazarotene 0.045% Fixed Combination

BACKGROUND

Psoriasis is a chronic condition often managed with topical therapy. Patients have high expectations about the speed at which improvement is achieved, which then can have a marked impact on the patient's adherence to treatment. Recently, clinical data on a new fixed combination of halobetasol and tazarotene (HP/TAZ) have been presented. HP/TAZ lotion was statistically more effective than individual active ingredients or its vehicle, with a predictable safety profile.

OBJECTIVES

Here we review the efficacy and tolerability data with a specific focus on the first two weeks of therapy.

METHODS

Multicenter, randomized, double-blind, vehicle-controlled Phase 2 study in moderate or severe psoriasis (N=212). Subjects randomized (2:2:2:1 ratio) to receive halobetasol 0.01%/tazarotene 0.045% (HP/TAZ), individual active ingredients (HP or TAZ), or vehicle, once-daily for 8 weeks. Efficacy assessments included treatment success (defined as at least a 2-grade improvement from baseline in the IGA score and a score of 'clear' or 'almost clear'), and impact on individual signs of psoriasis (erythema, plaque elevation, and scaling) at the target lesion.

RESULTS

As early as 2 weeks, HP/TAZ lotion demonstrated statistically significant superiority for treatment success over vehicle (P equals 0.047) and TAZ (P equals 0.029). By week 2, 47.5% of patients were 'mild', 'almost clear' or 'clear' compared with 33.3%, 16.9%, and 12.9% of patients treated with HP, TAZ, or vehicle, respectively; plaque elevation and scaling were significantly improved compared with HP, TAZ, or vehicle, and erythema was significantly improved compared with TAZ. Improvements in baseline itching (45.6%), dryness (42.2%), burning/stinging (55.9%) with HP/TAZ lotion at 2 weeks were similar to those seen with HP, and greater than that achieved with TAZ (30.8% [P equals 0.099], 35.4%, and 13.3%, respectively).

CONCLUSION

The HP/TAZ fixed combination lotion provides rapid relief of psoriasis symptoms, with apparent benefits over both HP and TAZ by week 2. J Drugs Dermatol. 2018;17(8):863-868.

3D printing of a wearable personalized oral delivery device: A first-in-human study

Despite the burgeoning interest in three-dimensional (3D) printing for the manufacture of customizable oral dosage formulations, a U.S. Food and Drug Administration-approved tablet notwithstanding, the full potential of 3D printing in pharmaceutical sciences has not been realized. In particular, 3D-printed drug-eluting devices offer the possibility for personalization in terms of shape, size, and architecture, but their clinical applications have remained relatively unexplored. We used 3D printing to manufacture a tailored oral drug delivery device with customizable design and tunable release rates in the form of a mouthguard and, subsequently, evaluated the performance of this system in the native setting in a first-in-human study. Our proof-of-concept work demonstrates the immense potential of 3D printing as a platform for the development and translation of next-generation drug delivery devices for personalized therapy.

Growth and characterization of organic NLO material: clobetasol propionate

Single crystals of clobetasol propionate (CP) have been grown by slow evaporation solution technique using mixed solvent of methanol-acetone. The grown crystals were subjected to single crystal X-ray diffraction analysis to confirm their lattice parameter and space group. The powder X-ray diffraction pattern of the grown CP has been indexed. Thermal analysis was performed to study the thermal stability of the grown crystals. Photoluminescence spectrum shows broad emission peak observed at 421 nm. Nonlinear optical studies were carried out for the grown crystal and second harmonic generation (SHG) efficiency was found in the crystal.

Nanoencapsulation of Clobetasol Propionate Decreases Its Penetration to Skin Layers Without Changing Its Relative Skin Distribution

An immunosuppressive effect with drug release control and higher NTPDase activity in the treatment of contact dermatitis was previously reported for a hydrogel containing 0.05% clobetasol propionate-loaded lipid-core nanocapsules (HG-LNC-CP) compared to a hydrogel containing the non-encapsulated drug (HG-CP). In order to investigate the factors underlying this different performance, we evaluated the in vitro skin permeation/penetration of CP from both formulations (HG-LNC-CP and HG-CP). CP did not permeate to the receptor medium during the experiment (24 h), but penetrated into the stratum corneum and viable skin (epidermis and dermis) in significant amounts after 24 h, regardless the type of the formulation. Comparing both formulations, although the relative amount of CP in each skin layer was not affected by the nanoencapsulation, HG-LNC-CP was able to reduce in 5.8, 6.9 and 3.7 times the amount of CP released into the stratum corneum, epidermis and dermis respectively. In this way, the higher effect of HG-LNC-CP previously observed could be due to the controlled drug penetration rate into the skin layers. Moreover, HG-LNC-CP reduces the chances of the corticosteroid to be absorbed systemically as the amount of CP reaching the dermis was reduced. The study reinforces the HG-LNC-CP as a promising dermatological nanomedicine for the treatment of skin disorders.

Nanocapsules prepared from amorphous polyesters: effect on the physicochemical characteristics, drug release, and photostability

The influence of the polymeric amorphous materials on the physicochemical and drug release properties of drug-loaded nanocapsules as well as their role on the protection of the entrapped drug against the degradation induced by UV radiation was evaluated. Nanocapsules were prepared by interfacial deposition of preformed polymer (PLA, PLGA 50:50, and PLGA 85:15) using clobetasol propionate as the drug model. In vitro drug release was evaluated by the dialysis bag method. Photochemical stability was studied under UVA radiation. After preparation, all formulations presented nanometric mean size (180-200 nm), polydispersity index below 0.20, acid pH, negative zeta potential, and encapsulation efficiency close to 100%. Clobetasol propionate-loaded PLGA nanocapsules presented a lower physicochemical stability, showing a high drug leakage during 3 months of storage. In vitro studies showed biphasic drug release from all nanocapsules (according to an anomalous transport) and no influence of the hydrophilic characteristics of the amorphous polymeric material on the release rate. The photostability of clobetasol propionate under UVA radiation was improved by its incorporation into PLA and PLGA nanocapsules showing that besides semicrystalline polymers, amorphous polymers could also efficiently protect nanoencapsulated drugs against UV radiation.

Solid lipid nanoparticles prepared by solvent diffusion method in a nanoreactor system

In this study, water-in-oil (W/O) miniemulsion was used as nanoreactor to prepare solid lipid nanoparticles (SLN) by solvent diffusion method. n-Hexane, Tween 80 and Span 80 were used as the oil phase and surfactant combination for preparation of W/O miniemulsion, respectively. The stable miniemulsion with the particle size of 27.1+/-7.6 nm was obtained when the composition of water/Tween 80/Span 80/n-hexane was 1 ml/18 mg/200 mg/10 ml. Clobetasol propionate (CP) was used as a model drug. The physicochemical properties of the SLN, such as particle size, zeta potential, surface morphology, drug entrapment efficiency, drug loading capacity and in vitro drug release behaviors were investigated, comparing with those of SLN prepared by conventional aqueoethod. The SLN prepared by the novel method displayed smaller particles size and higher dus solvent diffusion mrug entrapment efficiency than those of SLN prepared by the conventional method. The drug entrapment efficiency decreased with increasing of charged amount of drug, and 15.9% of drug loading was achieved as the charged amount of drug was 20%. The in vitro drug release tests indicated that the drug release rate was faster than that of SLN prepared by the conventional method, and the drug content in SLN did not affect the in vitro drug release profile.

A degradation product of halobetasol propionate: characterization and structure

Degradation of halobetasol propionate was observed in the presence of bases. A single cyclization product was isolated and fully characterized by MS, NMR and X-ray crystallography.

Preparation and characteristics of monostearin nanostructured lipid carriers

Nanostuctured lipid carriers (NLC) consisted of solid lipid and liquid lipid are a new type of lipid nanoparticles, which offer the advantage of improved drug loading capacity and release properties. In this study, solvent diffusion method was employed to produce NLC. Monostearin (MS) and caprylic/capric triglycerides (CT) were chosen as the solid lipid and liquid lipid. Clobetasol propionate used as a model drug was incorporated into the NLC. The influences of preparation temperature and CT content on physicochemical properties of the NLC were characterized. As a result, monostearin solid lipid nanoparticles (without CT content, SLN) obtained at higher temperature (70 degrees C) exhibited slightly higher drug loading capacity than that of 0 degrees C (P < 0.05). In contrast, the production temperature made little effect on NLC drug loading capacity (P > 0.05). The improved drug loading capacity was observed for NLC and it enhanced with increasing the CT content in NLC. The results were explained by differential scanning calorimetry (DSC) measurement for NLC. The incorporation of CT to NLC led to crystal order disturbance and thus left more space to accommodate drug molecules. NLC displayed a good ability to reduce the drug expulsion in storage compared to SLN. The in vitro release behaviors of NLC were dependent on the production temperature and CT content. NLC obtained at 70 degrees C exhibited biphasic drug release pattern with burst release at the initial 8h and prolonged release afterwards, whereas NLC obtained at 0 degrees C showed basically sustained drug release throughout the release time. The drug release rates were increased with increasing the CT content. These results indicated that the NLC produced by solvent diffusion method could potentially be exploited as a carrier with improved drug loading capacity and controlled drug release.

Clobetasol propionate foam in the treatment of psoriasis

Psoriasis is a common, chronic, distressing skin disorder that frequently affects the scalp, skin, nails and joints. Despite treatment, many patients suffer from unremitting disease and decreased quality of life. Scalp-type psoriasis is particularly difficult to treat. Although topical corticosteroids are the mainstay of therapy for moderate-to-severe disease, patients frequently object to the messiness and unfavourable cosmetic appearance of topical treatments. In this context, foam vehicles, which have the advantage of minimal residue and increased ease of application, have emerged as novel alternatives to traditional creams, ointments and solutions. Clobetasol propionate foam 0.05% (OLUX, Connetics Corporation), a high potency topical steroid, has been shown to alleviate symptoms of several dermatological conditions, including scalp and body psoriasis, improve disease severity and increase quality of life. Dose should be limited to 50 g/week, given the risk of adrenal suppression. Because patient preference is an important determinant of medication efficacy in clinical practice, clobetasol foam is a useful new formulation in the treatment of psoriasis and other skin conditions.

Diffusion modeling of percutaneous absorption kinetics: 3. Variable diffusion and partition coefficients, consequences for stratum corneum depth profiles and desorption kinetics

Stratum corneum (SC) desorption experiments have yielded higher calculated steady-state fluxes than those obtained by epidermal penetration studies. A possible explanation of this result is a variable diffusion or partition coefficient across the SC. We therefore developed the diffusion model for percutaneous penetration and desorption to study the effects of either a variable diffusion coefficient or variable partition coefficient in the SC over the diffusion path length. Steady-state flux, lag time, and mean desorption time were obtained from Laplace domain solutions. Numerical inversion of the Laplace domain solutions was used for simulations of solute concentration-distance and amount penetrated (desorbed)-time profiles. Diffusion and partition coefficients heterogeneity were examined using six different models. The effect of heterogeneity on predicted flux from desorption studies was compared with that obtained in permeation studies. Partition coefficient heterogeneity had a more profound effect on predicted fluxes than diffusion coefficient heterogeneity. Concentration-distance profiles show even larger dependence on heterogeneity, which is consistent with experimental tape-stripping data reported for clobetasol propionate and other solutes. The clobetasol propionate tape-stripping data were most consistent with the partition coefficient decreasing exponentially for half the SC and then becoming a constant for the remaining SC.

Preparation of solid lipid nanoparticles with clobetasol propionate by a novel solvent diffusion method in aqueous system and physicochemical characterization

Solid lipid nanoparticles (SLN) are a colloidal carrier system for controlled drug delivery. Monostearin SLN were prepared by a novel solvent diffusion method in an acidic aqueous system in order to improve the recovery of the method. The lipophilic model drug clobetasol propionate was incorporated to study the recovery of nanoparticles, entrapment efficacy, zeta potential (charge) and drug delivery characterization. The drug and monostearin were dissolved in acetone and ethanol at 50 degrees C in water bath, the resultant organic solution was poured into an acidic aqueous (pH 1.10) containing 1% polyvinyl alcohol (PVA) under mechanical agitation at room temperature. The drug loaded SLN was quickly produced with an aggregation state and easily separated by centrifugation. The recovery of nanoparticles was markedly increased compared to using a usual aqueous (pH 5.73) containing the same concentration of PVA. After burst drug release at the first 3 h, a distinctly prolonged release over a monitored period of 4 days was observed and nearly 6% drug was released in each day. Further, a novel preparation method and the optimized separation parameters in the present research for SLN were established. These results also demonstrate the principle suitability of SLN as a prolonged release formulation for lipophilic drugs.

Allergic contact dermatitis to preservatives in topical medicaments

BACKGROUND

Formaldehyde-releasing preservatives are well-known allergens found in many topical preparations including medications.

OBJECTIVE

To analyze the relevance of a positive patch test to formaldehyde-releasing preservatives in medications containing these preservatives.

METHODS

Patients were recruited with a history of allergy to one of these preservatives. Patch and use testing to the medications, vehicles, and preservatives were performed. The following medications and their respective preservatives were used: Renova 0.05% cream/quaternium-15, Dovonex 0.005% cream/diazolidinyl urea, and Temovate-E 0.05% cream/diazolidinyl urea.

RESULTS

Nine patients participated in the study. A positive patch test to the preservative was reproduced in six of nine patients, and a questionable reaction occurred in one. Two patients had a positive patch test to the topical medication and one a questionable reaction. There were no definitive positive patch tests to the vehicle but two questionable ones. Use testing revealed three positive reactions to Renova, one to Renova vehicle, and one to Temovate-E vehicle.

CONCLUSIONS

The concentration of the preservative in the commercial preparation was often below the threshold necessary to produce a clinical reaction. Use testing is a valuable tool in the complete evaluation of the patient with a positive patch test to a formaldehyde-releasing perservative found in topical medication.

Topical application of clobetasol 17-propionate from various cream bases by using Wistar rat as an animal model

The effect of clobetasol 17-propionate (CP), a potent corticosteroid, participating in various cream bases on the permeation through rat skin was tested in vitro. Three commercially available formulations and three cream bases prepared in our laboratory according to Pharmacopoeia or registered patent were evaluated in this present study. The amount of CP in the receptor phase of diffusion cell was negligible in the beginning of administration due to the process of saturation of drug in skin reservoir, then the CP molecules pass through the skin directly because of the saturation of receptors in skin reservoir followed the higher flux of CP in the later period. It was suggested that the incorporation of penetration enhancers was the possible reason mainly controlling the flux of CP creams. Nevertheless, CP residue in skin and the lag time of formulations prepared in our laboratory were not significantly higher than those of commercial ones, which indicated penetration enhancer could not dominate the local pharmacological effectiveness of CP though they played a main part on the skin penetration capacity of formulations. The antiinflammatory activity of CP was assessed in the ear of Wistar rat. According to the result of antiinflammatory activity, all formulations showed significant inhibition on oedema suggesting the role of drug itself may be more important than that of vehicle in controlling the therapy efficacy.