Pharmacokinetic evaluation of the synergistic effect of raloxifene loaded transfersomes for transdermal delivery

Development of propranolol loaded SLN for transdermal delivery: in-vitro characterization and skin deposition studies

AIM

The study aimed to formulate solid lipid nanoparticles (SLNs) for the transdermal delivery of PPL to improve skin retention and efficacy.

MATERIALS AND METHOD

The particle size distribution of SLNs was determined and the morphology of SLNs was also analyzed by SEM. In-vitro, ex-vivo and in vivo evaluations were done for PPL loaded SLN. The safety of drug delivery systems was assayed using MTT test.

RESULTS

The results indicated successful encapsulation of PPL in SLNs (59.38%), which exhibited a spherical shape and smooth surface. Compared to PPL solution, SLNs demonstrated a prolonged drug release profile in vitro. Stability tests over three months showed no significant changes in entrapment efficiency or size distribution. Enhanced permeation through shed snake and rat skin was observed with SLNs compared to the PPL solution. Ex-vivo and in vivo studies confirmed that PPL-loaded SLNs significantly increased drug content in the skin. Importantly, the SLNs displayed biocompatibility, as no significant cytotoxic effects were noted, and they were nonirritating to rat skin.

CONCLUSION

To the best of our knowledge, this is the first study that indicates SLNs can be considered as a promising nanocarriers for transdermal delivery of PPL.

Transfersome, an ultra-deformable lipid-based drug nanocarrier: an updated review with therapeutic applications

The application of nanotechnology with integration of chemical sciences is increasing continuously in the management of diseases. The drug's physicochemical and pharmacological characteristics are enhanced by application of nanotechnological principles. Several nanotechnology-based formulations are being investigated to improve patient compliance. One such novel nanocarrier system is transfersome (TFS) and is composed of natural biocompatible phospholipids and edge activators. Morphologically, TFS are similar to liposomes but functionally, these are ultra-deformable vesicles which can travel through pores smaller than their size. Because of their amphipathic nature, TFS have the potential to deliver the drugs through sensitive biological membranes, especially the blood-brain barrier, skin layers, and nasal epithelium. Different molecular weight drugs can be transferred inside the cell by encapsulation into the TFS. Knowing the tremendous potentiality of TFS, the present work provides an in-depth and detailed account (pharmaceutical and preclinical characteristics) of TFS incorporating different categories of therapeutic moieties (anti-diabetic, anti-inflammatory, anti-cancer, anti-viral, anti-fungal, anti-oxidant, cardiovascular drugs, CNS acting drugs, vaccine delivery, and miscellaneous applications). It also includes information about the methods of preparation employed, significance of excipients used in the preparation, summary of clinical investigations performed, patent details, latest investigations, routes of administration, challenges, and future progresses related to TFS.

Comparative Antibacterial and Efflux Pump Inhibitory Activity of Isolated Nerolidol, Farnesol, and α-Bisabolol Sesquiterpenes and Their Liposomal Nanoformulations

The efflux systems are considered important mechanisms of bacterial resistance due to their ability to extrude various antibiotics. Several naturally occurring compounds, such as sesquiterpenes, have demonstrated antibacterial activity and the ability to inhibit efflux pumps in resistant strains. Therefore, the objective of this research was to analyze the antibacterial and inhibitory activity of the efflux systems NorA, Tet(K), MsrA, and MepA by sesquiterpenes nerolidol, farnesol, and α-bisabolol, used either individually or in liposomal nanoformulation, against multi-resistant Staphylococcus aureus strains. The methodology consisted of in vitro testing of the ability of sesquiterpenes to reduce the Minimum Inhibitory Concentration (MIC) and enhance the action of antibiotics and ethidium bromide (EtBr) in broth microdilution assays. The following strains were used: S. aureus 1199B carrying the NorA efflux pump, resistant to norfloxacin; IS-58 strain carrying Tet(K), resistant to tetracyclines; RN4220 carrying MsrA, conferring resistance to erythromycin. For the EtBr fluorescence measurement test, K2068 carrying MepA was used. It was observed the individual sesquiterpenes exhibited better antibacterial activity as well as efflux pump inhibition. Farnesol showed the lowest MIC of 16.5 µg/mL against the S. aureus RN4220 strain. Isolated nerolidol stood out for reducing the MIC of EtBr to 5 µg/mL in the 1199B strain, yielding better results than the positive control CCCP, indicating strong evidence of NorA inhibition. The liposome formulations did not show promising results, except for liposome/farnesol, which reduced the MIC of EtBr against 1199B and RN4220. Further research is needed to evaluate the mechanisms of action involved in the inhibition of resistance mechanisms by the tested compounds.

Development and Characterization of Terbinafine-Loaded Nanoemulgel for Effective Management of Dermatophytosis

Dermatophytosis, the most prevalent fungal infection, is witnessing a rising incidence annually. To address this challenge, we developed a terbinafine-loaded oil-in-water nanoemulsion (TH-NE) through the aqueous microtitration method. The formulation comprised olive oil (oil phase), Span 80 (surfactant), and propylene glycol (co-surfactant). Pseudo-phase ternary diagrams and thermodynamic studies underscored the stability of TH-NE. Employing the Box-Behnken design (BBD), we optimized TH-NE, which resulted in a remarkable particle size of 28.07 nm ± 0.5, a low polydispersity index (PDI) of 0.1922 ± 0.1, and a substantial negative zeta potential of -41.87 mV ± 1. Subsequently, TH-NE was integrated into a 1.5% carbopol matrix, yielding a nanoemulgel (TH-NEG). Texture analysis of TH-NEG demonstrated a firmness of 168.00 g, a consistency of 229.81 g/s, negative cohesiveness (-83.36 g), and a work of cohesion at -107.02 g/s. In vitro drug release studies revealed an initial burst effect followed by sustained release, with TH-NEG achieving an impressive 88% release over 48 h, outperforming TH-NE (74%) and the marketed formulation (66%). Ex vivo release studies mirrored these results, with TH-NEG (86%) and TH-NE (71%) showcasing sustained drug release in comparison to the marketed formulation (67%). Confocal microscopy illustrated that TH-NEG and TH-NE penetrated to depths of 30 µm and 25 µm, respectively, into the epidermal layer. Furthermore, dermatokinetic studies highlighted the enhanced drug penetration of TH-NEG compared to TH-NE through mouse skin. In summary, our study establishes TH-NEG as a promising carrier for terbinafine in treating dermatophytosis, offering improved drug delivery and sustained release potential.

Design and Evaluation of Continentalic Acid Encapsulated Transfersomal Gel and Profiling of its Anti-arthritis Activity

Rheumatoid arthritis restricts the physical ability of patients and increases the disease burden; therefore, research has always been focused on evaluating better therapeutic options. The present research aimed to design Continentalic acid (CA)-loaded transfersomes (CA-TF) embedded in Carbopol gel containing permeation enhancer (PE) for the treatment of rheumatoid arthritis. CA-TF was developed via a modified thin film hydration method and incorporated into Carbopol 934 gel containing Eucalyptus oil (EO) as PE. The fabricated CA-TF showed particle size of < 140 nm with spherical geometry, optimal encapsulation efficiency (EE), and sustained drug release pattern. CA-TF-gel along with PE (CA-TF-PE-gel) showed better ex vivo skin penetration than plain CA gel and CA-TF-gel without PE. In vivo evaluation supported improved therapeutic outcomes of CA-TF-PE-gel in terms of behavioral findings, arthritic index, and histological findings whereas biochemical assays and pro-inflammatory cytokines (TNF-α and IL-1β) showed a significant decrease in their levels. Furthermore, immunohistochemistry assay for Nrf2 and HO-1 signaling pathways showed significant improvement in the expression of the Nrf2, and HO-1 proteins to depict improvement in arthritic condition in the animal model. CA-TF-PE-gel significantly delivered CA to the diseased target site via a topical route with promising therapeutic outcomes displayed in the CFA-induced arthritic model.

Nanostructured Lipid Carrier-Based Codelivery of Raloxifene and Naringin: Formulation, Optimization, In Vitro, Ex Vivo, In Vivo Assessment, and Acute Toxicity Studies

This work aimed to develop dual drug-loaded nanostructured lipid carriers of raloxifene and naringin (RLX/NRG NLCs) for breast cancer. RLX/NRG NLCs were prepared using Compritol 888 ATO and oleic acid using a hot homogenization-sonication method and optimized using central composite design (CCD). The optimized RLX/NRG NLCs were characterized and evaluated using multiple technological means. The optimized RLX/NRG NLCs exhibited a particle size of 137.12 nm, polydispersity index (PDI) of 0.266, zeta potential (ZP) of 25.9 mV, and entrapment efficiency (EE) of 91.05% (raloxifene) and 85.07% (naringin), respectively. In vitro release (81 ± 2.2% from RLX/NRG NLCs and 31 ± 1.9% from the RLX/NRG suspension for RLX and 93 ± 1.5% from RLX/NRG NLCs and 38 ± 2.01% from the RLX/NRG suspension for NRG within 24 h). Concurrently, an ex vivo permeation study exhibited nearly 2.3 and 2.1-fold improvement in the permeability profiles of RLX and NRG from RLX/NRG NLCs vis-à-vis the RLX/NRG suspension. The depth of permeation was proved with CLSM images which revealed significant permeation of the drug from the RLX/NRG NLCs formulation, 3.5-fold across the intestine, as compared with the RLX/NRG suspension. An in vitro DPPH antioxidant study displayed a better antioxidant potential of RLX/NRG in comparison to RLX and NRG alone due to the synergistic antioxidant effect of RLX and NRG. An acute toxicity study in Wistar rats showed the safety profile of the prepared nanoformulations and their excipients. Our findings shed new light on how poorly soluble and poorly permeable medicines can be codelivered using NLCs in an oral nanoformulation to improve their medicinal performance.

A Review on the Delivery of Plant-Based Antidiabetic Agents Using Nanocarriers: Current Status and Their Role in Combatting Hyperglycaemia

Diabetes mellitus is a prevalent metabolic syndrome that is associated with high blood glucose levels. The number of diabetic patients is increasing every year and the total number of cases is expected to reach more than 600 million worldwide by 2045. Modern antidiabetic drugs alleviate hyperglycaemia and complications that are caused by high blood glucose levels. However, due to the side effects of these drugs, plant extracts and bioactive compounds with antidiabetic properties have been gaining attention as alternative treatments for diabetes. Natural products are biocompatible, cheaper and expected to cause fewer side effects than the current antidiabetic drugs. In this review, various nanocarrier systems are discussed, such as liposomes, niosomes, polymeric nanoparticles, nanoemulsions, solid lipid nanoparticles and metallic nanoparticles. These systems have been applied to overcome the limitations of the current drugs and simultaneously improve the efficacy of plant-based antidiabetic drugs. The main challenges in the formulation of plant-based nanocarriers are the loading capacity of the plant extracts and the stability of the carriers. A brief review of lipid nanocarriers and the amphipathic properties of phospholipids and liposomes that encapsulate hydrophilic, hydrophobic and amphiphilic drugs is also described. A special emphasis is placed on metallic nanoparticles, with their advantages and associated complications being reported to highlight their effectiveness for treating hyperglycaemia. The present review could be an interesting paper for researchers who are working in the field of using plant extract-loaded nanoparticles as antidiabetic therapies.

Amorphization of Drugs for Transdermal Delivery-a Recent Update

Amorphous solid dispersion is a popular formulation approach for orally administered poorly water-soluble drugs, especially for BCS class II. But oral delivery could not be an automatic choice for some drugs with high first-pass metabolism susceptibility. In such cases, transdermal delivery is considered an alternative if the drug is potent and the dose is less than 10 mg. Amorphization of drugs causes supersaturation and enhances the thermodynamic activity of the drugs. Hence, drug transport through the skin could be improved. The stabilization of amorphous system is a persistent challenge that restricts its application. A polymeric system, where amorphous drug is dispersed in a polymeric carrier, helps its stability. However, high excipient load often becomes problematic for the polymeric amorphous system. Coamorphous formulation is another approach, where one drug is mixed with another drug or low molecular weight compound, which stabilizes each other, restricts crystallization, and maintains a single-phase homogenous amorphous system. Prevention of recrystallization along with enhanced skin permeation has been observed by the transdermal coamorphous system. But scalable manufacturing methods, extensive stability study and in-depth in vivo evaluation are lacking. This review has critically studied the mechanistic aspects of amorphization and transdermal permeation by analyzing recent researches in this field to propose a future direction.

Transdermal Delivery of Antigenic Protein Using Ionic Liquid-Based Nanocarriers for Tumor Immunotherapy

Transdermal drug delivery systems (TDDSs) may be useful for preventing various diseases including cancer. However, the stratum corneum (SC) inhibits the permeation of foreign particles into the skin. To obtain an effective TDDS, we developed a protein-containing nanocarrier (PCNC) comprising an antigenic protein (ovalbumin/OVA) stabilized by a combination of surfactants, i.e., a lipid-based surface-active ionic liquid and Tween-80. The PCNC was lyophilized to remove water and cyclohexane and then dispersed in isopropyl myristate. It is biocompatible both in vitro and in vivo, and is suitable for use in a therapeutic TDDS. The skin permeability of the PCNC was significantly (p < 0.0001) enhanced, and the transdermal distribution and transdermal flux of the OVA delivery system were 25 and 28 times greater, respectively, than those of its aqueous formulation. The PCNC disrupted the order of lipid orientation in the skin's SC and increased intercellular protein delivery. It demonstrated effective antitumor activity, drastically (p < 0.001) suppressed tumor growth, increased mouse survival rates, and significantly (p < 0.001) stimulated the OVA-specific tumor immune response. The PCNC also increased the number of cytotoxic T cells expressing CD8 antibodies on their surfaces (CD8 + T-cells) in the tumor microenvironment. These findings suggest that PCNCs may be promising biocompatible carriers for transdermal antigenic protein delivery in tumor immunotherapy.

Suppression of Melanoma Growth in a Murine Tumour Model Using Orthosiphon stamineus Benth. Extract Loaded in Ethanolic Phospholipid Vesicles (Spherosome

BACKGROUND

Orthosiphon stamineus Benth (O.S) is a traditional south-east Asian herb. The extract of O.S is used in the formulation of ethanolic nanolipid vesicle system to have considerable potential for tumour therapeutics.

METHOD

The research objective is to develop and characterise the anticancer and antiangiogenic effect of O.S extract in the form of nano-ethanolic spherosomes (ESP) using phospholipids in melanoma. Spherosomes formulation of O.S was developed using the thin-film re-hydration method and converted to gel using Acrypol 1%. The formulations were subjected to optimisation and physical-chemical characterisations like particle size, surface charge, DSC, FTIR, TEM. Cytotoxicity of O.S and ESP were studied using an endothelial cell line (EA. hy926). Furthermore, anti-melanoma effect of O.S spherosome gel was studied in albino mice after topical administration.

RESULTS

ESP-6 with the ratio of extract (O.S): cholesterol: phospholipid (1: 6: 0.5) showed the highest entrapment efficiency (80.56 ± 0.84%) using ultraviolet spectroscopy. In-vivo permeation/penetration studies revealed deeper absorption of ESP-6 compared with a hydroethanolic gel of O.S. In-vitro and in vivo anti-melanoma studies demonstrated the significant tumour-suppressing effect of ESP-6 on murine melanoma. Percentage inhibition of tumour growth by O.S and ESP-6 at 3000 mg/kg showed 63.98 ± 7.86% and 87.76 ± 7.90%, respectively.

CONCLUSION

Spherosome vesicles were developed with a smooth surface. The results demonstrated that O.S extract showed no toxicity when tested on the endothelial cell line. O.S loaded in spherosomes has the potential to lower the growth of melanoma in mice. The spherosomes loaded with O.S do not promote tumour growth or act as antiangiogenetic in melanoma.

Ibuprofen-Loaded Chitosan-Lipid Nanoconjugate Hydrogel with Gum Arabic: Green Synthesis, Characterisation, In Vitro Kinetics Mechanistic Release Study and PGE2 Production Test

Ibuprofen is a well-known non-steroidal anti-inflammatory (NSAID) medicine that is often used to treat inflammation in general. When given orally, it produces gastrointestinal issues which lead to lower patient compliance. Ibuprofen transdermal administration improves both patient compliance and the efficacy of the drug. Nanoconjugation hydrogels were proposed as a controlled transdermal delivery tool for ibuprofen. Six formulations were prepared using different compositions including chitosan, lipids, gum arabic, and polyvinyl alcohol, through ionic interaction, maturation, and freeze–thaw methods. The formulations were characterised by size, drug conjugation efficiency, differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). Further analysis of optimised hydrogels was performed, including X-ray diffraction (XRD), rheology, gel fraction and swelling ability, in vitro drug release, and in vitro macrophage prostaglandin E2 (PGE₂) production testing. The effects of ibuprofen’s electrostatic interaction with a lipid or polymer on the physicochemical and dissolution characterisation of ibuprofen hydrogels were evaluated. The results showed that the S3 (with lipid conjugation) hydrogel provided higher conjugation efficiency and prolonged drug release compared with the S6 hydrogel.

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.