Nanostructured Lipid Carriers Deliver Resveratrol, Restoring Attenuated Dilation in Small Coronary Arteries, via the AMPK Pathway.

Nanostructured lipid carriers (NLCs) are an emerging drug delivery platform for improved drug stability and the bioavailability of antihypertensive drugs and vasoprotective nutraceutical compounds, such as resveratrol (RV). The objective of this study was to ascertain NLCs' potential to deliver RV and restore attenuated dilator function, using an ex vivo model of acute hypertension. Trimyristin-triolein NLCs were synthesized and loaded with RV. The uptake of RV-NLCs by human coronary artery endothelial cells (HCAECs) maintained their viability and reduced both mitochondrial and cytosolic superoxide levels. Acute pressure elevation in isolated coronary arteries significantly attenuated endothelial-dependent dilator responses, which were reversed following incubation in RV-NLCs, superoxide dismutase or apocynin (p < 0.0001). RV-NLCs demonstrated a five-fold increase in potency in comparison to RV solution. At elevated pressure, in the presence of RV-NLCs, incubation with Nω-nitro-l-arginine (L-NNA) or indomethacin resulted in a significant reduction in the restored dilator component (p < 0.0001), whereas apamin and TRAM-34 had no overall effect. Incubation with the adenosine monophosphate-activated protein kinase (AMPK) inhibitor dorsomorphin significantly attenuated dilator responses (p < 0.001), whereas the SIRT-1 inhibitor EX-527 had no effect. RV-NLCs improved the impaired endothelial-dependent dilation of small coronary arteries, following acute pressure elevation, via NO and downstream COX elements, mediated by AMPK. We suggest that RV-NLCs are an effective delivery modality for improved potency and sustained drug release into the vasculature. Our findings have important implications for the future design and implementation of antihypertensive treatment strategies.

Fabrication, characterization and optimization of nanostructured lipid carrier formulations using Beclomethasone dipropionate for pulmonary drug delivery via medical nebulizers.

Aerosolization is a non-invasive approach in drug delivery for localized and systemic effect. Nanostructured lipid carriers (NLCs) are new generation versatile carriers, which offer protection from degradation and enhance bioavailability of poorly water soluble drugs. The aim of this study was to develop and optimize NLC formulations in combination with optimized airflow rates (i.e. 60 and 15 L/min) and choice of medical nebulizers including Air jet, Vibrating mesh and Ultrasonic nebulizer for superior aerosolization performance, assessed via a next generation impactor (NGI). Novel composition and combination of NLC formulations (F1 - F15) were prepared via ultrasonication method, employing five solid lipids (glycerol trimyristate (GTM), glycerol trilaurate (GTL), cetyl palmitate (CP), glycerol monostearate (GMS) and stearic acid (SA)); and three liquid lipids (glyceryl tributyrate (GTB), propylene glycol dicaprylate/dicaprate (PGD) and isopropyl palmitate (IPP)) in 1:3 w/w ratios (i.e. combination of one solid and one liquid lipid), with Beclomethasone dipropionate (BDP) incorporated as the model drug. Out of fifteen BDP-NLC formulations, the physicochemical properties of formulations F7, F8 and F10 exhibited desirable stability (one week at 25 °C), with associated particle size of ~241 nm, and >91% of drug entrapment. Post aerosolization, F10 was observed to deposit notably smaller sized particles (from 198 to 136 nm, 283 to 135 nm and 239 to 157 nm for Air jet, Vibrating mesh and Ultrasonic nebulizers, respectively) in all stages (i.e. from stage 1 to 8) of the NGI, when compared to F7 and F8 formulations. Six week stability studies conducted at 4, 25 and 45 °C, demonstrated F10 formulation stability in terms of particle size, irrespective of temperature conditions. Nebulizer performance study using the NGI for F10 identified the Air jet to be the most efficient nebulizer, depositing lower concentrations of BDP in the earlier stages (1-3) and higher (circa 82 and 85%) in the lateral stages (4-8) using 60 and 15 L/min airflow rates, when compared to the Vibrating mesh and Ultrasonic nebulizers. Moreover, at both airflow rates, the Air jet nebulizer elicited a longer nebulization time of ~42 min, facilitating aerosol inhalation for prophylaxis of asthma with normal tidal breathing. Based on characterization and nebulizer performance employing both 60 and 15 L/min airflow rates, the Air jet nebulizer offered enhanced performance, exhibiting a higher fine particle dose (FPD) (90 and 69 µg), fine particle fraction (FPF) (70 and 54%), respirable fraction (RF) (92 and 69%), and lower mass median aerodynamic diameter (MMAD) (1.15 and 1.62 µm); in addition to demonstrating higher drug deposition in the lateral parts of the NGI, when compared to its counterpart nebulizers. The F10 formulation used with the Air jet nebulizer was identified as being the most suitable combination for delivery of BDP-NLC formulations.

Potential Cardio-Protective Agents: A Resveratrol Review (2000-2019).

With a 2030 projection of 23.6 million deaths per year, the prevalence and severity of cardiovascular disease are astoundingly high. Thus, there is a definitive need for the identification of novel compounds with the potential to prevent or treat the disease and associated states. Moreover, there is also an ever-increasing need for drug delivery systems (DDS) that cope with poor and ranging physiochemical properties of therapeutic compounds to achieve the clinical effect. The usage of resveratrol (RES) is a growing area of interest with innumerate pieces of research, evidencing the drug's efficacy. This drug is, however, marred; its notably poor physiochemical properties (namely poor water solubility) limit its use for oral drug delivery. RES analogues, however, potentially possess superior physiochemical characteristics offering a remedy for the aforementioned drawback. However, particulate based DDS are equally able to offer property amelioration and targeting. This review offers an extensive examination into the role of RES as a potential cardioprotective agent. The prevalence and suitability of associated analogues and the role of nanotechnology in overcoming physicochemical boundaries, particularly through the development of nanoparticulate formulations, will be discussed in detail.

Generation of High Dose Inhalable Effervescent Dispersions against Pseudomonas aeruginosa Biofilms.

PURPOSE: Novel particle engineering approach was used in this study to generate high dose inhalable effervescent particles with synergistic effects against Pseudomonas aeruginosa biofilms. METHODS: Spray dried co-amorphous salt of ciprofloxacin (CFX) and tartaric acid (TA) was prepared and coated with external layer of sodium bicarbonate and silica coated silver nanobeads. Design of experiments (DOE) was used to optimize physicochemical properties of particles for enhanced lung deposition. RESULTS: Generated particles were co-amorphous CFX/TA showing that CFX lost its zwitterionic form and exhibiting distinct properties to CFX/HCl as assessed by FTIR and thermal analysis. Particles exhibited mass mean aerodynamic diameter (MMAD) of 3.3 µm, emitted dose of 78% and fine particle dose of 85%. Particles were further evaluated via antimicrobial assessment of minimum inhibitory concentrations (MIC) and minimum biofilm eradication concentration (MBEC). MIC and MBEC results showed that the hybrid particles were around 3-5 times more effective when compared to CFX signifying that synergistic effect was achieved. Diffusing wave spectroscopy results showed that the silver containing particles had a disruptive effect on rheological properties as opposed to silver free particles. CONCLUSIONS: Overall, these results showed the potential to use particle engineering to generate particles that are highly disruptive of bacterial biofilms.

A Facile and Novel Approach to Manufacture Paclitaxel-Loaded Proliposome Tablet Formulations of Micro or Nano Vesicles for Nebulization.

PURPOSE: The aim of this study was to develop novel paclitaxel-loaded proliposome tablet formulations for pulmonary drug delivery. METHOD: Proliposome powder formulations (i.e. F1 - F27) were prepared employing Lactose monohydrate (LMH), Microcrystalline cellulose (MCC) or Starch as a carbohydrate carriers and Soya phosphatidylcholine (SPC), Hydrogenated soya phosphatidylcholine (HSPC) or Dimyristoly phosphatidylcholine (DMPC) as a phospholipid. Proliposome powder formulations were prepared in 1:5, 1:15 or 1:25 w/w lipid phase to carrier ratio (lipid phase; comprising of phospholipid and cholesterol in 1:1 M ratio) and Paclitaxel (PTX) was used as model anticancer drug. RESULTS: Based on flowability studies, out of 27 formulations; F3, F6, and F9 formulations were selected as they exhibited an excellent angle of repose (AOR) (17.24 ± 0.43, 16.41 ± 0.52 and 15.16 ± 0.72°), comparatively lower size of vesicles (i.e. 5.35 ± 0.76, 6.27 ± 0.59 and 5.43 ± 0.68 µm) and good compressibility index (14.81 ± 0.36, 15.01 ± 0.35 and 14.56 ± 0.14) via Carr's index. The selected formulations were reduced into Nano (N) vesicles via probe sonication, followed by spray drying (SD) to get a dry powder of these formulations as F3SDN, F6SDN and F9SDN, and gave high yield (>53%) and exhibited poor to very poor compressibility index values via Carr's Index. Post tablet manufacturing, F3 tablets formulation showed uniform weight uniformity (129.40 ± 3.85 mg), good crushing strength (14.08 ± 1.95 N), precise tablet thickness (2.33 ± 0.51 mm) and a short disintegration time of 14.35 ± 0.56 min, passing all quality control tests in accordance with British Pharmacopeia (BP). Upon nebulization of F3 tablets formulation, Ultrasonic nebulizer showed better nebulization time (8.75 ± 0.86 min) and high output rate (421.06 ± 7.19 mg/min) when compared to Vibrating mesh nebulizer. PTX-loaded F3 tablet formulations were identified as toxic (60% cell viability) to cancer MRC-5 SV2 cell lines while safe to normal MRC-5 cell lines. CONCLUSION: Overall, in this study LMH was identified as a superior carbohydrate carrier for proliposome tablet manufacturing in a 1:25 w/w lipid to carrier ratio for in-vitro nebulization via Ultrasonic nebulizer.

Paclitaxel-loaded micro or nano transfersome formulation into novel tablets for pulmonary drug delivery via nebulization.

A simplistic approach was adopted to manufacture novel paclitaxel (PTX) loaded protransfersome tablet formulations for pulmonary drug delivery. The large surface area offered by the pulmonary system acts as a desirable site for anti-cancer drug deposition; offering localized effect within the lungs. Protransfersomes are dry powder formulations, whereas transfersomes are liquid dispersions containing vesicles generated from protransfersomes upon hydration. Protransfersome powder formulations (F1-F27) (referred as Micro formulations based on transfersomes vesicles size post hydration) were prepared by employing a phospholipid (Soya phosphatidylcholine (SPC)), three different carbohydrate carriers (Lactose monohydrate, LMH; Microcrystalline cellulose, MCC; and Starch), three surfactants (i.e. Span 80, Span 20 and Tween 80) in three different lipid phase to carrier ratios (i.e. 1:05, 1:15 and 1:25 w/w), with the incorporation of PTX as a model drug. Hydrophobic chain of SPC may enhance PTX solubility, entrapment and targetted delivery via transfersome vesicles. Out of the 27 Micro protransfersome formulations, PTX-loaded LMH powder formulations F3, F6 and F9 (i.e. 1:25 w/w lipid phase to carrier ratio) exhibited excellent powder flowability via angle of repose (AOR) and good compressibility index due to associated smaller and uniform particle size and shape of LMH. Following hydration, these formulations also showed smaller volume median diameters (VMD) in micrometres (5.65 ± 0.85-6.76 ± 0.61 µm) and PTX entrapment of 93-96%. Hydrated transfersome formulations (F3, F6 and F9) were converted into Nano size via probe sonication and referred to as Nano formulations. These Nano formulations were converted into dry powder via spray drying (SD) (F3NSD, F6NSD and F9NSD) or freeze drying (FD) (F3NFD, F6NFD and F9NFD). Post manufacture of protransfersome tablets (i.e. 9 formulations), quality control tests were conducted in accordance to British Pharmacopeia (BP). Only the Micro formulations protransfersome tablets (i.e. F3, F6 and F9) passed the uniformity of weight test, exhibited high crushing strength and tablet thickness when compared to SD or FD protransfersome tablets. Micro protransfersome formulations (i.e. F3, F6 and F9) into tablets demonstrated a shorter nebulization time and high output rate when using Ultrasonic nebulizer compared to Vibrating mesh nebulizer (i.e. Omron NE U22). Based on formulations, characterizations and nebulizer performance; Micro protransfersome tablet formulations F3, F6 and F9 (i.e. 1:25 w/w) and Ultrasonic nebulizer were found to be a superior combination, eliciting enhanced output efficiency. Moreover, PTX-loaded F3, F6 and F9 tablet formulations (10%) exhibited toxicity (60, 68 and 67% cell viability) to cancer MRC-5 SV2 (i.e. immortalized human lung cells) while safe to MRC-5 (normal lung fibroblast cells) cell lines.

Potential of Natural Biomaterials in Nano-scale Drug Delivery.

BACKGROUND: The usage of natural biomaterials or naturally derived materials intended for interface with biological systems has steadily increased in response to the high demand of amenable materials, which are suitable for purpose, biocompatible and biodegradable. There are many naturally derived polymers which overlap in terms of purpose as biomaterials but are equally diverse in their applications. METHODS: This review examines the applications of the following naturally derived polymers; hyaluronic acid, silk fibroin, chitosan, collagen and tamarind polysaccharide (TSP); further focusing on the biomedical applications of each as well as emphasising on individual novel applications. RESULTS: Each of the polymers was found to demonstrate a wide variety of successful biomedical applications fabricated as wound dressings, scaffolds, matrices, films, sponges, implants or hydrogels to suit the therapeutic need. Interestingly, blending and amelioration of polymer structures were the two selection strategies to modify the functionality of the polymers to suit the purpose. Further, these polymers have shown promise to deliver small molecule drugs, proteins and genes as nano-scale delivery systems. CONCLUSION: The review highlights the range of applications of the aforementioned polymers as biomaterials. Hyaluronic acid, silk fibroin, chitosan, collagen and TSP have been successfully utilised as biomaterials in the subfields of implant enhancement, wound management, drug delivery, tissue engineering and nanotechnology. Whilst there are a number of associated advantages (i.e. biodegradability, biocompatibility, non-toxic, nonantigenic as well as amenability) the selected disadvantages of each individual polymer provide significant scope for their further exploration and overcoming challenges like feasibility of mass production at a relatively low cost.