Vinpocetine loaded ultradeformable liposomes as fast dissolving microneedle patch: Tackling treatment challenges of dementia

Potential Use of Common Administration of Emulsion for Parenteral Nutrition and Vinpocetine: Compatibility Study and Prospect

Vinpocetine (VP) is distributed after oral and intravenous administration, and its uptake in the thalamus, basal ganglia, and visual cortex. Due to poor bioavailability (~7%) and marked first-pass effect (~75%), including a short half-life (2-3 h), oral administration of VP is limited. It requires frequent administration of the drug to obtain a therapeutic effect. Attempts to overcome these difficulties include the use of new drug delivery systems and/or alternative routes of drug administration. One possibility is the common administration of lipid emulsion and drug using the same catheter. However, this procedure is not recommended due to potential interaction and lack of safety data. For this purpose, we checked the compatibility of VP solutions with eight commercially available parenteral nutrition admixtures, i.e., Lipoflex special, Omegaflex special, Lipoflex peri, Omegaflex peri, Kabiven, SmofKabiven, Kabiven Peripheral, and Olimel Peri N4E. Coadministration is only possible if the stability of the drug and the lipid emulsion is confirmed. The available data are scarce and only concern the incompatibility of VP with ibuprofen. Compatibility tests were carried out in simulated administration through a Y-site connector using clinical flow rates. The stability of the drug and lipid emulsion was assessed by visual inspection and measurement of pH, osmolality, particle size as mean droplet diameter (MDD) and percentage of lipids residing in globules larger than 5 µm (PFAT5), zeta potential, polydispersity index, and lipid-free parenteral nutrition admixture(PNA) turbidity. The results of the compatibility of VP with eight commercial PN admixtures showed that all lipid emulsions show different signs of destabilization. In the studied samples, particles larger than 1000 nm, a significant increase in MDD, zeta potential, and loss of homogeneity visible as an increase in the polydispersity index were observed. Most of the samples had PFAT5 above the USP limit (0.05%). Taking into account the obtained data, VP should not be administered with the studied lipid emulsions for parenteral nutrition.

Overcoming challenges in dermal and transdermal delivery of herbal therapeutics with polymeric microneedles

Natural products are generally preferred medications owing to their low toxicity and irritancy potential. However, a good number of herbal therapeutics (HT) exhibit solubility, permeability and stability issues that eventually affect oral bioavailability. Transdermal administration has been successful in resolving some of these issues which has lead in commercialization of a few herbal transdermal products. Polymeric Microneedles (MNs) has emerged as a promising platform in transdermal delivery of HT that face problems in permeating the skin. Several biocompatible and biodegradable polymers used in the fabrication of MNs have been discussed. MNs have been exploited for cutaneous delivery of HT in management of skin ailments like skin cancer, acne, chronic wounds and hypertrophic scar. Considering the clinical need, MNs are explored for systemic delivery of potent HT for management of diverse disorders like asthma, disorders of central nervous system and nicotine replacement as it obviates first pass metabolism and elicits a quicker onset of therapeutic response. MNs of HT have found good number of aesthetic applications in topical delivery of HT to the skin. Interestingly, MNs have emerged as an attractive option as a minimally invasive diagnostic aid in sampling biomarkers from plants, skin and ocular interstitial fluid. The review updates the progress made by MN technology of HT for multiple therapeutic interventions along with the future challenges. An attempt is made to illustrate the challenging formulation strategies employed in the fabrication of polymeric MNs of HT. Efforts are on to extend the potential applications of polymeric MNs to HT for diverse therapeutic applications.

Formulation Development of Fast Dissolving Microneedles Loaded with Cubosomes of Febuxostat: In Vitro and In Vivo Evaluation

Febuxostat is a widely prescribed drug for the treatment of gout, which is a highly prevalent disease worldwide and is a major cause of disability in mankind. Febuxostat suffers from several limitations such as gastrointestinal disturbances and low oral bioavailability. Thus, to improve patient compliance and bioavailability, transdermal drug delivery systems of Febuxostat were developed for obtaining enhanced permeation. Cubosomes of Febuxostat were prepared using a bottom-up approach and loaded into a microneedle using a micromolding technique to achieve better permeation through the skin. Optimization of the process and formulation parameters were achieved using our design of experiments. The optimized cubosomes of Febuxostat were characterized for various parameters such as % entrapment efficiency, vesicle size, Polydispersity index, Transmission electron microscopy, in vitro drug release, Small angle X-ray scattering, etc. After loading it in the microneedle it was characterized for dissolution time, axial fracture force, scanning electron microscopy, in vitro drug release, pore closure kinetics, etc. It was also evaluated for various ex vivo characterizations such as in vitro cell viability, ex vivo permeation, ex vivo fluorescence microscopy and histopathology which indicates its safety and better permeation. In vivo pharmacokinetic studies proved enhanced bioavailability compared with the marketed formulation. Pharmacodynamic study indicated its effectiveness in a disease-induced rat model. The developed formulations were then subjected to the stability study, which proved its stability.

Advances in microneedles for delivery of active ingredients of natural herbals

The active ingredients of natural herbs have been extracted to act on different targets in the body to exert multiple effects. However, traditional oral administration and intravenous injection of herbal medicines are also susceptible to many side effects. Transdermal drug delivery by microneedles can overcome the shortcomings of these traditional drug delivery systems. The active ingredients of natural herbs can be delivered to the dermis or the connective tissue layer by five types of microneedles: solid, hollow, coated, dissolving, and hydrogel. Subsequently, the herbal ingredients are delivered to different target points of the body through body circulation to exert their effects. In this study, we classified the microneedles that can deliver the active ingredients of natural herbs and summarized their advantages and disadvantages as well as their preparation methods and applications, to guide the development and clinical applications of other herbal transdermal microneedles.

Trilayer dissolving polymeric microneedle array loading Rose Bengal transfersomes as a novel adjuvant in early-stage cutaneous melanoma management

Melanoma remains a global concern, but current therapies present critical limitations pointing out the urgent need for novel strategies. Among these, the cutaneous delivery of drugs selectively damaging cancer cells is highly attractive. Rose Bengal (RB) is a dye exhibiting selective cytotoxicity towards melanoma, but the high water solubility and low permeability hinder its therapeutic potential. We previously developed RB-loaded transfersomes (RBTF) to mediate the RB dermal delivery; however, a platform efficiently delivering RBTF in the deepest strata is essential for a successful therapeutic activity. In this regard, dissolving microneedles release the encapsulated cargo up to the dermis, painlessly piercing the outmost skin layers. Therefore, herein we developed and characterised a trilayer dissolving microneedle array (RBTF-TDMNs) loading RBTF to maximise RBTF intradermal delivery in melanoma management. RBTF-TDMNs were proven strong enough to pierce excised porcine skin and rapidly dissolve and deposit RBTF intradermally while maintaining their physicochemical properties. Also, 3D visualisation of the system itself and while penetrating the skin was performed by multi-photon microscopy. Finally, a dermatokinetic study showed that RBTF-TDMNs offered unique delivery efficiency advantages compared to RBTF dispersion and free drug-loaded TDMNs. The proposed RBTF-TDMNs represent a valuable potential adjuvant tool for the topical management of melanoma.

Celecoxib nanocrystal-loaded dissolving microneedles with highly efficient for osteoarthritis treatment

Osteoarthritis (OA) is a prevalent degenerative disease that has a significant impact on patients' lives. Celecoxib (CXB) is now primarily used to treat OA with oral dosing. CXB's limited water solubility, on the other hand, restricts its therapeutic application. We developed a delivery system of dissolving microneedles (DMNs) loaded with CXB-nanocrystals (CXB-NCs) for the treatment of OA. Oral administration's inefficiency and injectable administration's poor compliance might be solved using DMNs. Furthermore, carrier-free NCs may dramatically increase the dissolution of drugs with poorly water-solubility, as well as the drug load of DMNs. Antisolvent precipitation was used to make CXB-NCs. CXB-NC@DMNs were prepared by mixing CXB-NCs with hyaluronic acid (HA) that had high mechanical qualities and could permeate the skin efficiently in vitro. The therapeutic effect of oral CXB-NCs was substantially better than that of the same dose of oral CXB in an in vivo pharmacodynamic trial, demonstrating that the preparation of CXB into NCs might greatly increase CXB bioavailability. Furthermore, we discovered that DMNs loaded with low-dose CXB-NCs had similar or even better efficacy than the oral CXB-NCs group. The findings suggested that CXB-NC@DMNs may be a very efficient and promising drug delivery strategy in the treatment of OA.

Enhancement of the Transdermal Delivery of Nonsteroidal Anti-inflammatory Drugs Using Liposomes Containing Cationic Surfactants

New hybrid liposomes based on cationic amphiphiles with different structures of the head group (cetyltrimethylammonium bromide (CTAB), 3-hexadecyl-1-hydroxyethylimidazolium bromide (IA-16(OH)), 1-(butylcarbamoyl)oxyethyl-3-hexadecylimidazolium bromide (IAC 16(Bu)), and hexadecylmethylpyrrolidinium bromide (PR-16)) were developed for transdermal administration of nonsteroidal anti-inflammatory drugs. The different surfactant/lipid compositions were studied to obtain stable liposomes with high functionality. The hydrodynamic diameter of cationic liposomes was ∼110 nm. An admixture of cationic surfactants and PC liposomes improves the physicochemical properties of vesicles and transdermal diffusion rate and prolongs the release of drugs. Liposomal diclofenac sodium (DS) and ketoprofen (KP) were tested (using Franz cells) for transdermal penetration. Drug diffusion monitoring for 48 h demonstrated that the maximum DS and KP penetration through the synthetic membranes (Strat-M) is characterized by values of 255 ± 2 and 186 ± 3 μg/cm², respectively. The influence of the surfactant head group on the properties (stability, release profile, permeability) of cationic liposomes was shown for the first time. While the drug specificity is evident for the rate of release, the permeability increases as follows: conventional liposomes < CTAB/PC < PR-16/PC < IAC-16(Bu)/PC < IA-16(OH)/PC for both medicines. The rat paw edema model was used to assess the anti-inflammatory effect of the IA-16(OH)/PC leader formulation in vivo. It was found that liposomal DS and KP are effective for relieving rat paw edema. It should be noted that DS-loaded hybrid liposomes demonstrated the highest therapeutic efficacy compared to conventional vesicles.

Microneedle-mediated transdermal nanodelivery systems: a review

The greatest limitation in the development of transdermal drug delivery systems is that only a few drugs can permeate the skin due to the barrier function of the stratum corneum. Active and passive methods are generally available for improving the ability of drug transdermal delivery. However, nanoparticles, as a passive approach, exhibit capacity-constrained permeation enhancement. Thus, microneedle-mediated nanoparticles possess enormous potential and broad prospects. Microneedles promote the penetration of macromolecules by creating microchannels on the skin surface. In this review, the prevailing subknowledge on microneedles (mechanism, classification, and applications of microneedles combined with nanoparticles) is discussed to provide a guideline for readers and a basic reference for further in-depth studies of this novel drug delivery system.

Strategy for osteoarthritis therapy: Improved the delivery of triptolide using liposome-loaded dissolving microneedle arrays

Osteoarthritis (OA) is a chronic disease that seriously impairs people's physical function and quality of life. Triptolide (TP), as a promising anti-inflammatory drug for the treatment of OA, has limited clinical application due to its severe systemic toxicity, poor solubility and rapid elimination in the body. To extend its application prospect for OA treatment. We have developed a liposome-loaded dissolving microneedle (DMN) system, which can effectively deliver poorly water-soluble TP and improve OA symptoms. To incorporate TP into DMNs, triptolide liposome (TP-Lipo) with entrapment efficiency of 90.25% was prepared by ethanol injection. Subsequently, TP-Lipo was concentrated by ultrafiltration tube and mixed with hyaluronic acid solution to prepare DMNs, TP-Lipo-loaded DMNs (TP-Lipo@DMNs) showed sufficient mechanical and insertion properties to penetrate about 200 μm of rat skin. The drug distribution in vivo showed that TP-Lipo@DMNs had a slow-release effect compared with intra-articular injection. In vivo pharmacodynamic research showed that TP-Lipo@DMNs significantly reduced knee joint swelling and the level of inflammatory cytokines (TNF-α, IL-1β, IL-6). Micro-CT and histological evaluation showed that TP-Lipo@DMNs effectively reduced cartilage destruction and alleviated OA symptoms. These results support that TP@Lipo@DMNs may be a promising option for OA treatment.

Dissolving Microneedles Developed in Association with Nanosystems: A Scoping Review on the Quality Parameters of These Emerging Systems for Drug or Protein Transdermal Delivery

The largest organ of the body provides the main challenge for the transdermal delivery of lipophilic or high molecular weight drugs. To cross the main barrier of the skin, the stratum corneum, many techniques have been developed and improved. In the last 20 years, the association of microneedles with nanostructured systems has gained prominence for its versatility and for enabling targeted drug delivery. Currently, the combination of these mechanisms is pointed to as an emerging technology; however, some gaps need to be answered to transcend the development of these devices from the laboratory scale to the pharmaceutical market. It is known that the lack of regulatory guidelines for quality control is a hindrance to market conquest. In this context, this study undertakes a scoping review of original papers concerning methods applied to evaluate both the quality and drug/protein delivery of dissolving and hydrogel-forming microneedles developed in association with nanostructured systems.

Panorama of dissolving microneedles for transdermal drug delivery

Recently, microfabrication technology has been developed to increase the permeability of drugs for transdermal delivery. Microneedles are ultra-small needles usually in the micron size range (different dimensions in micron), generate pores, and allow for delivery of local medication in the systemic circulation via skin. The microneedles have been available in dissolving, solid, coated, hollow, and hydrogel-based microneedles. Dissolving microneedles have been fabricated using micro-molding, photo-polymerization, drawing lithography and droplet blowing techniques. Dissolving microneedles could be a valuable option for the delivery of low molecular weight drugs, peptides, enzymes, vaccines and bio-therapeutics. It consists of water-soluble materials including maltose, polyvinyl pyrrolidone, chondroitin sulfate, dextran, hyaluronic acid, and albumin. The microneedles have almost dissolved after patch removal, leaving only blunt stubs behind, which are easily removable. In this review, we summarize the major building blocks, classification, fabrication techniques, characterization, diffusion models and application of microneedles in diverse area. We also reviewed the regulatory aspects, computational studies, patents, clinical data, and market trends of microneedles.

Fabrication, evaluation and applications of dissolving microneedles

In recent years, transdermal preparations have emerged as one of the most promising modes of administration. In particular, dissolving microneedles have attracted extensive attention because of their painlessness, safety, high delivery efficiency and easily operation for patients. This article mainly reviews the preparation methods, the types of matrix polymer materials, the content of dissolving microneedles performance testing, and the applications of dissolving microneedles. It is expected to lay a solid knowledge foundation for the in-depth study of the dissolving microneedles.