Statistical optimization of tretinoin-loaded penetration-enhancer vesicles (PEV) for topical delivery

Release of Tretinoin Solubilized in Microemulsion from Carbopol and Xanthan Gel: In Vitro versus Ex Vivo Permeation Study

BACKGROUND

Tretinoin (TRE) is, for its anti-comedogenic and comedolytic activity, widely used in the topical treatment of acne vulgaris. The effect lies in the regulation of sebum production and collagen synthesis. The study is devoted to the formulation of dermal gels containing TRE using microemulsion as the drug solubilizer.

METHODS

The aim was to evaluate the effect of the reference microemulsion (ME) and lecithin-containing microemulsion (ME_L) on the release of TRE through the synthetic membrane (in vitro) and the pig's ear skin (ex vivo) through the Franz cell diffusion method. Subsequently, after an ex vivo study, the amount of the drug in the skin influenced by the applied formulation was determined. In addition, the impact of ME on the microscopic structure, texture, and rheological properties of gels was evaluated.

RESULTS

On the basis of the analysis of texture, rheological properties, and drug release studies, Carbopol formulations appear to be more appropriate and stable. Considering the synthetic membrane as a stratum corneum, the Carbopol gel penetrated about 2.5-higher amounts of TRE compared to the Xanthan gel. In turn, ex vivo studies suggest that ME_L slows the drug transfer to the dissolution medium, simulating absorption into the blood, which is a desirable effect in local treatment. The drug retention study proved the highest amounts of TRE in the skin to which microemulsion-Carbopol formulations were applied.

CONCLUSION

The results confirm the benefit of TRE solubilization in ME due to its bioavailability from the tested dermal formulations.

Enhancing Topical Pharmacotherapy for Acne and Rosacea: Vehicle Choices and Outcomes

The choice of vehicle is an important consideration in the treatment of acne and rosacea. Agents used to treat these common conditions may be limited by multiple factors, including poor stability during storage, limited residence time in the skin and follicular unit, and high potential for skin irritation. Novel drug delivery systems have been developed to address these problems, including microencapsulation, liposomal encapsulation, and the use of a variety of nanocarriers. New vehicle technologies for acne and rosacea treatments have appeared over the past 20 years and have somewhat improved stability, tolerability, and possibly efficacy. One of the latest vehicle technologies in acne and rosacea to enhance efficacy, stability, and tolerability is microencapsulation of benzoyl peroxide and tretinoin, which resulted in significant efficacy and good tolerability in patients with each of these two diseases. Other new vehicle technologies include a polymeric form of tretinoin and a microsphere product that combines tretinoin plus clindamycin. It is likely that there will be more reports of clinical success as experience with the rapidly evolving delivery technologies increases. This review summarizes drug delivery systems that have been developed with the aim of improving outcomes for patients being treated for either acne or rosacea. It also focuses, where possible, on formulations that have been evaluated in clinical studies.

Insightful exploring of advanced nanocarriers for the topical/transdermal treatment of skin diseases

Dermatological products constitute a big segment of the pharmaceutical market. From conventional products to more advanced ones, a wide variety of dosage forms have been developed till current date. A representative of the advanced delivery means is carrier-based systems, which can load large number of drugs for treatment of dermatological diseases, or simply for cosmeceutical purposes. To make them more favorable for topical delivery, further incorporation of these carriers in a topical vehicle, such as gels or creams is made. Therefore in this review article, an overview is compiled of the most commonly encountered novel carrier based topical delivery systems; namely lipid based (nanoemulsions, microemulsions, solid lipid nanoparticles [SLNs] and nanostructured lipid carriers [NLCs]), and vesicular carriers (non-deformable, such as liposomes, niosomes, emulsomes and cerosomes, and deformable, such as transfersomes, ethosomes, transethosomes, and penetration enhancer vesicles), with special emphasis on those loaded in a secondary gel vehicle. A special focus was made on the commonly encountered dermatological diseases, such as bacterial and fungal infections, psoriasis, dermatitis, eczema, vitiligo, oxidative damage, aging, alopecia, and skin cancer.

Recent Advancement in Topical Nanocarriers for the Treatment of Psoriasis

Psoriasis is a life-threatening autoimmune inflammatory skin disease, triggered by T lymphocyte. Recently, the drugs most commonly used for the treatment of psoriasis include methotrexate (MTX), cyclosporine (CsA), acitretin, dexamethasone, and salicylic acid. However, conventional formulations due to poor absorptive capacity, inconsistent drug release characteristics, poor capability of selective targeting, poor retention of drug molecules in target tissue, and unintended skin reactions restrict the clinical efficacy of drugs. Advances in topical nanocarriers allow the development of prominent drug delivery platforms can be employed to address the critical issues associated with conventional formulations. Advances in nanocarriers design, nano-dimensional configuration, and surface functionalization allow formulation scientists to develop formulations for a more effective treatment of psoriasis. Moreover, interventions in the size distribution, shape, agglomeration/aggregation potential, and surface chemistry are the significant aspects need to be critically evaluated for better therapeutic results. This review attempted to explore the opportunities and challenges of current revelations in the nano carrier-based topical drug delivery approach used for the treatment of psoriasis.

Co-loading of finasteride and baicalin in phospholipid vesicles tailored for the treatment of hair disorders

Hair loss affects a large number of people worldwide and it has a negative impact on the quality of life. Despite the availability of different drugs for the treatment of hair disorders, therapeutic options are still limited and scarcely effective. An innovative strategy to improve the efficacy of alopecia treatment is presented in this work. Finasteride, the only oral synthetic drug approved by Unites States Federal Drug Administration, was loaded in phospholipid vesicles. In addition, baicalin was co-loaded as an adjuvant. Their effect on hair growth was evaluated in vitro and in vivo. Liposomes, hyalurosomes, glycerosomes and glycerol-hyalurosomes were manufactured by using a simple method that avoids the use of organic solvents. All the vesicles were small in size (∼100 nm), homogeneously dispersed (polydispersity index ≤0.27) and negatively charged (∼-16 mV). The formulations were able to stimulate the proliferation of human dermal papilla cells, which are widely used in hair physiology studies. The analysis of hair growth and hair follicles of C57BL/6 mice, treated with the formulations for 21 days, underlined the ability of the vesicles to improve hair growth by the simultaneous follicular delivery of finasteride and baicalin. Therefore, the developed nanosystems can represent a promising tool to ensure the efficacy of the local treatment of hair loss.

An update on formulation strategies of benzoyl peroxide in efficient acne therapy with special focus on minimizing undesired effects

Benzoyl peroxide (BPO) in the form of over the counter monotherapeutics or prescription-only combinations is a key component of topical acne therapy, but its unfavourable side effect profile reduces the therapeutic value of this compound. Various galenic approaches have been pursued to resolve this ambivalence, but only a few have managed to enter the market. This article aims to give a comprehensive overview of the published experimental vehicle systems and to identify the fundamental rationales. With regard to the formulation, an increase in the tolerability of BPO can essentially be achieved by combining BPO with re-fattening and moisturizing substances, by incorporating it and controlling its release, as well as by targeted deposition of the active ingredient at the site of action, i.e. drug targeting. Recently, novel particulate formulations have been proposed that combine several of these design principles and are expected to bring new developments in this dynamic field of research.

Targeted Topical Delivery of Retinoids in the Management of Acne Vulgaris: Current Formulations and Novel Delivery Systems

Acne vulgaris is a common inflammatory pilosebaceous condition that affects 80-90% of adolescents. Since the introduction of tretinoin over 40 years ago, topical retinoid products have been a mainstay of acne treatment. The retinoids are very effective in addressing multiple aspects of the acne pathology as they are comedolytic and anti-inflammatory, and do not contribute to antibiotic resistance or microbiome disturbance that can be associated with long-term antibiotic therapies that are a common alternative treatment. However, topical retinoids are associated with skin dryness, erythema and pain, and may exacerbate dermatitis or eczema. Thus, there is a clear need to target delivery of the retinoids to the pilosebaceous units to increase efficacy and minimise side effects in surrounding skin tissue. This paper reviews the current marketed topical retinoid products and the research that has been applied to the development of targeted topical delivery systems of retinoids for acne.

Formulation and evaluation of letrozole-loaded spray dried liposomes with PEs for topical application

Letrozole (LET), an aromatase inhibitor widely used as a first-line drug for the estrogen-dependent breast cancer treatment in postmenopausal women. In this study, an attempt has been made to develop LET topical drug delivery which would be a more efficient system to treat elevated blood levels of estrogen found in breast cancer patients. The technique involves, encapsulation of the LET in phospholipids using spray dryer. The LET spray-dried powder (LT-SDP) powder was tested by Fourier transform infrared, X-RD, and differential scanning calorimetry. These studies confirm the entrapment efficiency (EE) of the system. The LT-SDP in the form dispersion was further evaluated. The confocal laser scanning microscopy (CLSM) showed spherical vesicles, the particle size, polydispersity index, and the EE was found to be 284.0 nm, 0.247, and 59.08%, respectively. LT-SDP dispersion was added into a cream base with peppermint and olive oil as natural penetration enhancers. Optimized formulation showed superior skin targeting in in vitro and in vivo studies. Cell proliferation assay and flow cytometry was carried out using human cancer cell line of breast MDA-MB-231 which showed superior anti-proliferative action and enhanced apoptosis activity of LT-SDP cream (43.9%) in comparison. The CLSM micrograph, skin irritation, and histopathology studies showed the penetration ability and inertness of the LT-SDP cream, respectively. In vivo bioavailability studies showed an almost four-fold increase in the plasma concentration (11.3 versus 4.2) while the mean residence time (81.11 versus 64.42 h) and half-life (51.01 versus 39.36 h) were reasonably higher than plain LET cream.

Understanding the prospective of nano-formulations towards the treatment of psoriasis

Psoriasis is a consistently recurring, inflammatory, autoimmune disorder of the skin, affecting about 2-5% of the world population. Abundant therapeutic agents are accessible for the treatment of psoriasis. Nevertheless, none of them are entirely secure and effective to treat the disease without compromising patient compliance. Furthermore, already existing drugs are supposed to restrain the ailment and alleviate the sign and symptoms with no complete cure. However, they focus on restraining the disease and alleviating the symptoms without providing an absolute cure. Therefore there remains a vital challenge, to explore a new drug moiety or delivery system which could safely and effectively manage psoriasis without compromising patient compliance. Furthermore, conventional formulations offer reduced benefit/risk ratio of anti-psoriatic drugs, which limits the use of existing conventional formulations. Novel formulations based on nanocarriers are a promising prospect to overcome the limitation of conventional formulations by offering a reduction in dose, dosing frequency, dose-dependent, side effects with enhanced efficacy. Presently nano-formulations have gained widespread application for effective and safe treatment of psoriasis. The present review primarily focuses on conventional therapeutic strategy and recent advances in lipid-based, polymer-based and metallic nano-formulations of a variety of anti-psoriatic drugs. The practicability of various nanocarrier systems including liposomes, nanostructured lipid carriers, ethosomes, solid lipid nanoparticles, nanocapsules, micelles, dendrimers, gold nanoparticles and silver nanoparticles have been discussed in detail. The review also traces related patents to exemplify the role of various nanoparticles in psoriasis treatment. In a nutshell, nano-formulations remain established as a promising modality for treating psoriasis treatment as they propose better penetration, targeted delivery, enhanced safety, and efficacy.

Elastic liposomes as novel carriers: recent advances in drug delivery

Elastic liposomes (EL) are some of the most versatile deformable vesicular carriers that comprise physiologically biocompatible lipids and surfactants for the delivery of numerous challenging molecules and have marked advantages over other colloidal systems. They have been investigated for a wide range of applications in pharmaceutical technology through topical, transdermal, nasal, and oral routes for efficient and effective drug delivery. Increased drug encapsulation efficiency, enhanced drug permeation and penetration into or across the skin, and ultradeformability have led to widespread interest in ELs to modulate drug release, permeation, and drug action more efficiently than conventional drug-release vehicles. This review provides insights into the versatile role that ELs play in the delivery of numerous drugs and biomolecules by improving drug release, permeation, and penetration across the skin as well as stability. Furthermore, it provides future directions that should ensure the widespread use of ELs across all medical fields.