Colloidal carriers of isotretinoin for topical acne treatment: skin uptake, ATR-FTIR and in vitro cytotoxicity studies

Strategic development of aceclofenac loaded organosomes for topical application: An explorative ex-vivo and in-vivo investigation for arthritis

Present study intends to develop aceclofenac-encapsulated organosomes (OS), which consist of phospholipids coupled with a combination of organic solvents, for the management of arthritis. The formulation was characterized and tested for efficacy using formalin-induced hyperalgesia, air pouch, and CFA-induced arthritic rat models. OS system exhibited spherical dimension, nanometric size with low PDI (278.3 ± 12.21 nm; 0.145), zeta potential (-24.56 ± 7.53 mV), drug entrapment (85.62 ± 7.2 %) and vesicles count (4.2x104 mm3). The gelled OS formulation demonstrated increased drug permeability and accumulation rate (51.77 ± 7.1 % and 396.19 ± 59.21 µg/cm2) compared to the MKT product (102.93 ± 13.78 µg/cm2 and 16.14 ± 4.3 %). Dermatokinetic assessments exhibited significantly higher drug levels in dermal layers compared to MKT product (p < 0.001), and CLSM studies further supported the OS system's deeper penetration. The results of arthritic index significantly better (9 times) in the OS-treated group than the MKT product. OS system treatment significantly reduced biochemicals and cytokines levels, such as CRP, ESR, TLC, lymphocytes, TNF-α, IL-6, and IL-1β to levels of the control group (p < 0.001). Pseudoplastic behaviour of the developed product was indicated by the rheological results, and it also demonstrated biocompatibility through skin compliance studies. Based on the current findings, it appears that OS may be a better choice for managing arthritis and related inflammations.

Exploring the therapeutic potential of sodium deoxycholate tailored deformable-emulsomes of etodolac for effective management of arthritis

The current piece of research intends to evaluate the potential of combining etodolac with deformable-emulsomes, a flexible vesicular system, as a promising strategy for the topical therapy of arthritis. The developed carrier system featured nanometric dimensions (102 nm), an improved zeta potential (- 5.05 mV), sustained drug release (31.33%), and enhanced drug deposition (33.13%) of DE-gel vis-à-vis conventional system (10.34% and 14.71%). The amount of permeation of the developed nano formulation across skin layers was demonstrated through CLSM and dermatokinetics studies. The safety profile of deformable-emulsomes has been investigated through in vitro HaCaT cell culture studies and skin compliance studies. The efficacy of the DE-gel formulation was sevenfold higher in case of Xylene induced ear edema model and 2.2-folds in CFA induced arthritis model than that of group treated with conventional gel (p < 0.01). The main technological rationale lies in the use of phospholipid and sodium deoxycholate-based nanoscale flexible lipoidal vesicles, which effectively encapsulate drug molecules within their interiors. This encapsulation enhances the molecular interactions and facilitates the transportation of the drug molecule effectively to the target-site. Hence, these findings offer robust scientific evidence to support additional investigation into the potential utility of flexible vesicular systems as a promising drug delivery alternative for molecules of this nature.

Influence of cryopreservation methods of ex vivo rat and pig skin on the results of in vitro permeation test

In vitro permeation test (IVPT) is a frequently used method for in vitro assessment of topical preparations and transdermal drug delivery systems. However, the storage of ex vivo skin for IVPT remains a challenge. Here, two cryopreservation media were chosen to preserve rat and pig skin at -20 °C and -80 °C for further IVPT, namely, 10% DMSO and 10% GLY. The skin viability test confirmed that the skin protective capacity of 10% DMSO and 10% GLY was almost equal. The results of skin viability and IVPT showed that the skin viability and permeability of rat skin in 10%DMSO or 10% GLY were maintained for at least 7 and 30 days at -20 °C and -80 °C compared to fresh skin, respectively; in contrast, those of porcine skin were just maintained for less than 7 days at -20 °C and -80 °C. These results indicated that ex vivo skin for IVPT preserved at -80 °C in 10% DMSO or 10% GLY was optimal. Furthermore, skin permeability was independent of skin barrier integrity. Our study provides reference conditions for preserving IVPT skin, and skin viability can be a potential indicator of IVPT skin.

Azelaic acid loaded chitosan and HPMC based hydrogels for treatment of acne: formulation, characterization, in vitro-ex vivo evaluation

In this study, hydrogels containing azelaic acid were developed using chitosan or HPMC (1-7%) for local treatment of acne vulgaris. Physicochemical properties such as viscosity, pH and mechanical properties were evaluated. In vitro release and ex vivo permeability studies were performed using Franz diffusion cell system. The pH of the hydrogels were highly compatible with the skin pH and varied between 4.38-5.84. The cumulative release percentages of the hydrogels at the end of 6 hours were 65-78%, whereas the marketed product yielded 50% drug release. According to the ex vivo permeability results, azelaic acid accumulated in the skin were found to be 9.38 ± 0.65% (marketed cream), 19.53 ± 1.06% (K3), 10.96 ± 1.91% (H6). The antiacne studies with Cutibacterium acnes revealed that K3 (29.45 ± 0.95) and H6 (32.35 ± 0.15) had higher inhibition zones compared to the marketed cream (24.50 ± 0.90). Additionally, the gels were found to be highly stable as a result of the stability studies for 6 months. Among the hydrogels that were prepared based on experimental findings, K3 (3% Chitosan) and H6 (6% HPMC) represented elevated in vitro release profile, higher permeability and increased antiacne activity. The findings of this research suggest that the developed hydrogels might be an alternative to the marketed product.

Co-delivery of isotretinoin and clindamycin by phospholipid-based mixed micellar system confers synergistic effect for treatment of acne vulgaris

BACKGROUND

The combination therapy of Isotretinoin (ITR) and antibacterial formulations administered through topical route suffer from several limitations including reduced therapeutic efficacy and low patient-compliance.

EXPERIMENT

The present study aimed to develop biocompatible lipid-based mixed micelles of ITR in combination with Clindamycin phosphate (CLIN) employing self-assembly method to improve its skin delivery, photostability, biocompatibility and pharmacodynamic efficacy.

RESULTS

The MTT assay and cellular uptake studies showed non-cytotoxic effect to HaCat cell lines. The zone of inhibition studies conducted in Propionibacterium acnes provides the first literature evidence to support the antimicrobial property of Isotretinoin and Tretinioin. The nano-sized carriers offered (19.3 ± 1.03 nm particle size with -3.12 mV zeta potential) enhanced permeation, skin retention, pre-clinical efficacy and significant skin biocompatibility. The testosterone-induced acne model proved superior pharmacodynamic efficacy of lab developed formulation vis-à-vis marketed products of both the drugs. The results were further confirmed by the histopathological studies of respective skin samples treated with different formulations.

CONCLUSION

The lab developed lipid-based micellar formulation of ITR and CLIN offers a better strategy for the combined delivery of unstable molecules like ITR and CLIN in acne management.

Foray into Concepts of Design and Evaluation of Microemulsions as a Modern Approach for Topical Applications in Acne Pathology

With a fascinating complexity, governed by multiple physiological processes, the skin is considered a mantle with protective functions which during lifetime are frequently impaired, triggering dermatologic disorders. As one of the most prevalent dermatologic conditions worldwide, characterized by a complex pathogenesis and a high recurrence, acne can affect the patient's quality of life. Smart topical vehicles represent a good option in the treatment of a versatile skin condition. By surpassing the stratum corneum known for diffusional resistance, a superior topical bioavailability can be obtained at the affected place. In this direction, the literature study presents microemulsions as a part of a condensed group of modern formulations. Microemulsions are appreciated for their superior profile in matters of drug delivery, especially for challenging substances with hydrophilic or lipophilic structures. Formulated as transparent and thermodynamically stable systems, using simplified methods of preparation, microemulsions have a simple and clear appearance. Their unique structures can be explained as a function of the formulation parameters which were found to be the mainstay of a targeted therapy.

Part 1. Evaluation of Epigallocatechin Gallate or Tannic Acid Formulations of Hydrophobic Drugs for Enhanced Dermal and Bladder Uptake or for Local Anesthesia Effects

Epigallocatechin gallate (EGCG) and tannic acid (TA) are known to increase the aqueous solubility and cellular uptake of the hydrophobic drugs docetaxel, paclitaxel, amphotericin B, and curcumin. In this study the practical application of gallate-based solubilization phenomena for the uptake of these drugs into dermal and bladder tissue and of lidocaine for wound healing application was studied. The penetration of all these drugs into pig skin or docetaxel into pig bladder using EGCG or TA formulations was measured. Overall, EGCG and TA particulate or propylene glycol paste formulations of drugs allowed for greatly increased levels of drug uptake into skin as compared to control formulations. EGCG/propylene glycol pastes allowed for rapid lidocaine uptake into skin. EGCG and TA formulations of docetaxel allowed for approximately 10 fold increases in bladder tissue uptake of docetaxel over tween based solutions. Morphologically, both EGCG and TA caused a mild, dose dependent exfoliation of the bladder wall. Both EGCG and TA formed injectable viscous pastes with propylene glycol which solidified in water and degraded and released lidocaine over 2-35 days. These data support the use of EGCG and TA based formulations of certain drugs for improved dermal, bladder and wound applications.

Paper 2. Epigallocatechin Gallate and Tannic Acid Based Formulations of Finasteride for Dermal Administration and Chemoembolization

Finasteride is used to treat benign prostatic hyperplasia (BPH) and pattern hair loss (androgenetic alopecia or APA). The local administration of formulations with increased solubility and controlled release of finasteride are proposed using gallate-containing compositions within embolic microparticles or paste. Finasteride solubility in either epigallocatechin gallate (EGCG) or tannic acid (TA) solutions was assessed using HPLC. Poly(dl-lactide-co-glycolide) (PLGA) or poly(methylmethacrylate) (PMMA) microspheres (100-400 μm) containing finasteride and EGCG or TA were effectively manufactured. Embolic particles were loaded with finasteride/EGCG/TA. Dermal uptake of TA/EGCG/finasteride topical compositions was measured in pig skin. The solubility of finasteride was dramatically increased using EGCG- or TA-based compositions. Finasteride loaded microspheres released over two months which was increased by EGCG or TA inclusion. Embolic particles soaked up finasteride and EGCG or TA and released the encapsulated drug over two weeks. Dermal uptake of finasteride from EGCG- or TA-based formulations was enhanced between 10 and 50 fold in layers as deep as 500 μm when compared to a generic control formulation. Gallate-based formulations of finasteride increase drug solubility and allow for effective release of the drug from embolic formulations. Paste or powder EGCG- or TA-based formulations of finasteride greatly increase dermal penetration of the drug.

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.

Topical and cutaneous delivery using nanosystems

The goal of topical and cutaneous delivery is to deliver therapeutic and other substances to a desired target site in the skin at appropriate doses to achieve a safe and efficacious outcome. Normally, however, when the stratum corneum is intact and the skin barrier is uncompromised, this is limited to molecules that are relatively lipophilic, small and uncharged, thereby excluding many potentially useful therapeutic peptides, proteins, vaccines, gene fragments or drug-carrying particles. In this review we will describe how nanosystems are being increasingly exploited for topical and cutaneous delivery, particularly for these previously difficult substances. This is also being driven by the development of novel technologies, which include minimally invasive delivery systems and more precise fabrication techniques. While there is a vast array of nanosystems under development and many undergoing advanced clinical trials, relatively few have achieved full translation to clinical practice. This slow uptake may be due, in part, to the need for a rigorous demonstration of safety in these new nanotechnologies. Some of the safety aspects associated with nanosystems will be considered in this review.

Colloidal nanocarriers for the enhanced cutaneous delivery of naftifine: characterization studies and in vitro and in vivo evaluations

In topical administration of antifungals, the drugs should pass the stratum corneum to reach lower layers of the skin in effective concentrations. Thus, the formulation of antifungal agents into a suitable delivery system is important for the topical treatment of fungal infections. Nanosized colloidal carriers have gained great interest during the recent years to serve as efficient promoters of drug penetration into the skin. Microemulsions are soft colloidal nanosized drug carriers, which are thermodynamically stable and isotropic systems. They have been extensively explored for the enhancement of skin delivery of drugs. This study was carried out to exploit the feasibility of colloidal carriers as to improve skin transport of naftifine, which is an allylamine antifungal drug. The microemulsions were formulated by construction of pseudoternary phase diagrams and composed of oleic acid (oil phase), Kolliphor^® EL or Kolliphor^® RH40 (surfactant), Transcutol^® (cosurfactant), and water (aqueous phase). The plain and drug-loaded microemulsions were characterized in terms of isotropy, particle size and size distribution, pH value, refractive index, viscosity, and conductivity. The in vitro skin uptake of naftifine from microemulsions was studied using tape stripping technique in pig skin. The drug penetrated significantly into stratum corneum from microemulsions compared to its marketed cream (P<0.05). Moreover, the microemulsion formulations led to highly significant amount of naftifine deposition in deeper layers of skin than that of commercial formulation (P<0.001). Microemulsion–skin interaction was confirmed by attenuated total reflectance – Fourier transformed infrared spectroscopy data, in vitro. The results of the in vivo tape stripping experiment showed similar trends as the in vitro skin penetration study. Topical application of the microemulsion on human forearms in vivo enhanced significantly the distribution and the amount of naftifine penetrated into the stratum corneum as compared to the marketed formulation (P<0.05). The relative safety of the microemulsion formulations was demonstrated with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide viability test. This study indicated that the nanosized colloidal carriers developed could be considered as an effective and safe topical delivery system for naftifine.