Preparation of intravenous stealthy acyclovir nanoparticles with increased mean residence time

Intranasal administration of innovative triamcinolone acetonide encapsulated cubosomal in situ gel: formulation and characterization

AIM

The primary objective of the research was to develop a cubosomal in situ gel encapsulated with Triamcinolone acetonide (TCA) in order to enhance its penetration through the blood-brain barrier (BBB) when administered via the intranasal route, thus enabling efficient and rapid action.

METHOD

Cubosomes were formulated by top-down approach using glyceryl monooleate (GMO), using pluronics127 (PF127) and polyvinyl alcohol (PVA) in varying proportions based on the Box-Behnken design. High resolution transmission electron microscopy (HR-TEM) analysis confirmed the morphology of the cubosomes. The in situ gel was formulated and optimized. Experiments involving ex vivo permeation and histopathology analyses were undertaken to evaluate drug permeation and tissue effects.

RESULTS

The cubosomes exhibited a particle size (PS) of 197.9 nm, zeta potential (ZP) of -31.11 mV, and entrapment efficacy (EE) of 84.31%, with low deviation. Batch F4 (19% PF127) showed favorable results. In vitro and ex vivo permeation studies revealed drug release of 78.59% and 76.65%, respectively, after 8 h. Drug release followed the Hixson Crowell model of release kinetics. The histopathological examination revealed no signs of toxicity or adverse effects on the nasal mucosa of the sheep. The formulation exhibited short-term stability, maintaining its integrity and properties when stored at room temperature.

CONCLUSION

The utilization of an intranasal cubosomal in situ gel encapsulated with TCA was anticipated to lower intracranial pressure and improve patient adherence by offering effective relief for individuals suffering from Brain edema. This efficacy is attributed to its rapid onset of action and its safe and well-tolerated dosage form.

Polymer-Based Nanoparticles as Drug Delivery Systems for Purines of Established Importance in Medicine

Many purine derivatives are active pharmaceutical ingredients of significant importance in the therapy of autoimmune diseases, cancers, and viral infections. In many cases, their medical use is limited due to unfavorable physicochemical and pharmacokinetic properties. These problems can be overcome by the preparation of the prodrugs of purines or by combining these compounds with nanoparticles. Herein, we aim to review the scientific progress and perspectives for polymer-based nanoparticles as drug delivery systems for purines. Polymeric nanoparticles turned out to have the potential to augment antiviral and antiproliferative effects of purine derivatives by specific binding to receptors (ASGR1-liver, macrophage mannose receptor), increase in drug retention (in eye, intestines, and vagina), and permeation (intranasal to brain delivery, PEPT1 transport of acyclovir). The most significant achievements of polymer-based nanoparticles as drug delivery systems for purines were found for tenofovir disoproxil in protection against HIV, for acyclovir against HSV, for 6-mercaptopurine in prolongation of mice ALL model life, as well as for 6-thioguanine for increased efficacy of adoptively transferred T cells. Moreover, nanocarriers were able to diminish the toxic effects of acyclovir, didanosine, cladribine, tenofovir, 6-mercaptopurine, and 6-thioguanine.

Nano Drug Delivery Platforms for Dental Application: Infection Control and TMJ Management-A Review

The oral cavity is an intricate environment subjected to various chemical, physical, and thermal injuries. The effectiveness of the local and systemically administered drugs is limited mainly due to their toxicities and poor oral bioavailability that leads to the limited effectiveness of the drugs in the target tissues. To address these issues, nanoparticle drug delivery systems based on metals, liposomes, polymeric particles, and core shells have been developed in recent years. Nano drug delivery systems have applications in the treatment of patients suffering from temporomandibular joint disorders such as preventing degeneration of cartilage in patients suffering from rheumatoid arthritis and osteoarthritis and alleviating the pain along with it. The antibacterial dental applications of nano-drug delivery systems such as silver and copper-based nanoparticles include these agents used to arrest dental caries, multiple steps in root canal treatment, and patients suffering from periodontitis. Nanoparticles have been used in adjunct with antifungals to treat oral fungal infections such as candida albicans in denture wearers. Acyclovir being the most commonly used antiviral has been used in combination with nanoparticles against an array of viral infections such as the herpes simplex virus. Nanoparticles based combination agents offer more favorable drug release in a controlled manner along with efficient delivery at the site of action. This review presents an updated overview of the recently developed nanoparticles delivery systems for the management of temporomandibular joint disorders along with the treatment of different oral infections.

Inhibition of aldehyde dehydrogenase by furazolidone nanoemulsion to decrease cisplatin resistance in lung cancer cells

Aim: The overexpression of aldehyde dehydrogenase (ALDH) in cancer cells contributes to therapeutic resistance. Furazolidone (FUR) is a strong ALDH inhibitor. Methods: FUR nanoemulsion (NE) was formulated and tested for ALDH inhibitory activity in comparison with free FUR. The cytotoxic potential of cisplatin was evaluated in combination with free FUR and FUR NE. Results: The optimized FUR NE showed droplet size of 167.9 ± 3.1 nm and drug content of 84.2 ± 2.3%. FUR NE inhibited 99.75 ± 2.1% of ALDH activity while 25.0 ± 4.6% was inhibited by free FUR. FUR NE increased the sensitivity to cisplatin in A549 cells by more than tenfold by its ALDH inhibitory effects. Conclusion: This finding can be a promising approach to improve cancer survival in ALDH-positive drug-resistant cancers.

Transdermal Film Loaded with Garlic Oil-Acyclovir Nanoemulsion to Overcome Barriers for Its Use in Alleviating Cold Sore Conditions

The exponentially mounting cases of herpes simplex virus infection or cold sores have become a serious global concern. Acyclovir (ACV) and garlic oil (GO)-loaded lipid nanocarrier could be a promising therapeutic approach in alleviating cold sores, as well as limiting the biopharmaceutical constraints associated with ACV absorption and therapeutic efficacy. Therefore, the objective of the current research study was to formulate an ACV-GO self-nanoemulsifying drug delivery system (ACV-GO-SNEDDS) as transdermal films. The prepared SNEDDS was optimized using an experimental mixture design. The optimized ACV-GO SNEDDS was loaded in transdermal film and was evaluated for ex vivo skin permeation and in vivo pharmacokinetic prospects. An optimized ACV-GO SNEDDs formulation constituted of 10.4% (w/w) of GO, 64.8% (w/w) of surfactant mixture (Tween 20^®-Span 20^®); 24.8%(w/w) of co-surfactant (Propylene glycol^®), and 200mg of ACV, respectively, were prepared and characterized for particle size (Y). The observed globule size of the optimized ACV-GO SNEDDS is 170 ± 13.45 nm. The results of stability studies indicated that the stability index of optimized ACV-GO-SNEDDS was more than 92 ± 3%. This optimized ACV-GO SNEDDS was loaded in hydroxypropyl cellulose transdermal film. The outcome of the ex vivo skin permeation study demonstrated a 2.3-fold augmented permeation of ACV from the optimized ACV-GO SNEDDS HPC transdermal film in comparison to the raw ACV transdermal film. There was a 3-fold increase in the relative bioavailability of the optimized ACV-GO SNEDDS transdermal film compared to the raw ACV-HPC film. The study findings confirmed that the ACV-GO SNEDDS transdermal film exhibited excellent potential to enhance the bioavailability of ACV.

Cubogel as potential platform for glaucoma management

The aim of this work is to survey the potential of cubogel as an ocular dosage form to boost the corneal permeability of Dorzolamide Hydrochloride DZ; an antiglaucomal drug. DZ-loaded cubosomal dispersions were prepared according to Box-Behnken design, where the effect of independent variables; Monoolein MO concentration (2.5, 5 and 7.5%w/w), Pluronic^® F127 concentration (0.25, 0.5 and 0.75%w/w) and magnetic stirrer speed of (400, 800 and 1200 rpm) was studied on PS (nm), Zp (−mV) and Q 2 h (%) respectively. The prepared formulae were characterized via drug content DC (%), particle size PS (nm), polydispersity index PDI, zeta potential Zp (−mV), in-vitro drug release (Q 2 h%) and finally TEM. The optimized formulation composed of: 6.13% w/w of MO, 0.75% w/w of F127 and prepared at 1200 rpm stirring speed was chosen based on the criteria of minimum PS (nm), maximum Zp (−mV) and minimum Q 2 h (%). Results revealed that the optimum formula showed PS of 153.3 ± 8.4 n, Zp of 32 ± 3 −mV and 37.78 ± 1.3% released after 2 h. Carbopol 934 (1% w/v) as gelling agent was used to prepare the optimum cubogel, which was further evaluated by DSC, ex-vivo permeation and stability studies at 4 °C for three months. Moreover, in vivo studies of the optimized cubogel include; draize test, histological examination, confocal laser scanning microscopy (CLSM) and intraocular pressure (IOP) measurement. Results revealed that the optimized cubogel was considerably safe, stable and competent to corneal delivery as assured by draize and histological examination. CLSM showed a deeper penetration of more than 2.5-fold. A higher bioavailability (288.24 mg. h/ml) was attained from cubogel compared to the market product Trusopt^® eye drops (115.40 mg. h/ml) following IOP measurement. Therefore, DZ-loaded cubogel could be considered as promising delivery system to boost the transcorneal permeation hence corneal bioavailability of DZ as antiglaucomal drug.

Formulation of acyclovir-loaded solid lipid nanoparticles: design, optimization, and in-vitro characterization

The goal of this study was to design, optimize, and characterize Acyclovir-loaded solid lipid nanoparticles (ACV-SLNs) concerning particle size, zeta potential, entrapment efficiency, and release profile. Full factorial design (2³) was applied and the independent variables were surfactant type (Tween 80 and Pluronic F68), lipid type (Stearic acid and Compritol 888 ATO), and co-surfactant type (Lecithin and Sodium deoxycholate). The microemulsion technique was used followed by ultrasonication. The ACV-SLNs had a particle size range of about 172-542 nm. The polydispersity index (PDI) was found to be between 0.193 and 0.526. Zeta potential was in the range of -25.7 to -41.6 mV indicating good physical stability. Entrapment efficiency values were in the range of 56.3-80.7%. The drug release kinetics of the prepared formulations was best fitted to Higuchi diffusion model. After storing ACV-SLNs at refrigerated condition (5 ± 3 °C) and room temperature (25 ± 2 °C) for 4 weeks; we studied the change in the particle size, PDI, and zeta potential. The selected optimized formulation (F4) was containing Compritol, Pluronic F68, and Lecithin. These results indicated the successful application of this design to optimize the ACV-SLNs as a promising delivery system.

Formulation of acyclovir-loaded solid lipid nanoparticles: 2. Brain targeting and pharmacokinetic study

Acyclovir (ACV) is widely used in the treatment of herpes encephalitis. The present study was conducted to prepare chitosan-tween 80 coated solid lipid nanoparticles (SLNs) as a delivery system for brain targeting of ACV in rabbits. The SLNs were prepared and coated in one step by microemulsion method using a coating solution containing chitosan (0.1% w/v) and tween 80 (2% w/v) for loading sustained release ACV. In vitro characterization was performed for coated ACV-SLNs. Concerning in vivo experiments; a single intravenous bolus dose of coated ACV-SLNs was given versus free ACV solution to rabbits (62 mg/kg). Plasma pharmacokinetic parameters were calculated from the ACV concentration-time profiles in plasma using the two compartmental analysis. The values of AUC_0-∞ and MRT of coated ACV-SLNs were higher than free drug by about twofold, 233.36 ± 41.56 μg.h/mL and 1.81 ± 0.36 h, respectively. The noncompartmental analysis was conducted to estimate the brain pharmacokinetic parameters. The AUC_0-∞ brain/AUC_0-∞ plasma ratio for coated ACV-SLNs and free ACV was 0.22 and 0.12, respectively. These results indicated the effectiveness of using coated ACV-SLNs for brain targeting.

Niosomes: A Strategy toward Prevention of Clinically Significant Drug Incompatibilities

Drug incompatibilities are considered as one of the most critical problems in intensive care units. In the current study, the ability of nanomaterials to prevent drug incompatibilities in clinical settings has been investigated. As a proof-of-concept, the ability of niosomes to prevent physical and chemical incompatibilities that occur upon mixing acyclovir and vancomycin during management of acute meningitis has been explored. Nanosized spherical particles loaded separately with either vancomycin or acyclovir, with high entrapment efficiency (ca. 46–56%), could be prepared, and sustained release of their entrapped cargoes have been demonstrated over time. We have shown that precipitation, degradation and loss of biological activity of drugs occurred upon mixing solutions of the free drugs. On the contrary, drugs loaded separately inside niosomal structures exhibited high stability, exceptional physical and chemical compatibilities for up to 48 h with complete preservation of the antimicrobial activity of vancomycin. This study opens a venue for a new spectrum of applications of nanomaterials in preventing clinically significant drug incompatibilities, aiming at the reduction of adverse reactions, cost and hospitalization period, and improvement of patient compliance and therapeutic outcomes.

Current applications of nanoparticles in infectious diseases

For decades infections have been treated easily with drugs. However, in the 21st century, they may become lethal again owing to the development of antimicrobial resistance. Pathogens can become resistant by means of different mechanisms, such as increasing the time they spend in the intracellular environment, where drugs are unable to reach therapeutic levels. Moreover, drugs are also subject to certain problems that decrease their efficacy. This requires the use of high doses, and frequent administrations must be implemented, causing adverse side effects or toxicity. The use of nanoparticle systems can help to overcome such problems and increase drug efficacy. Accordingly, there is considerable current interest in their use as antimicrobial agents against different pathogens like bacteria, virus, fungi or parasites, multidrug-resistant strains and biofilms; as targeting vectors towards specific tissues; as vaccines and as theranostic systems. This review begins with an overview of the different types and characteristics of nanoparticles used to deliver drugs to the target, followed by a review of current research and clinical trials addressing the use of nanoparticles within the field of infectious diseases.

Development and optimisation of mucoadhesive nanoparticles of acyclovir using design of experiments approach

The aim of our study was to improve the bioavailability of acyclovir (ACV) by delivery of mucoadhesive nanoparticles (NPs) and controlled delivery of drug at its absorption window. Central composite design was used by which the effects of independent variables (gelatin and Pluronic F-68) on various responses such as particle size, polydispersity index, entrapment efficiency, loading efficiency, drug release and mucoadhesive strength were studied. The optimised formulation was evaluated for morphology, stability, pharmacokinetic and gastrointestinal tracking. The optimised NPs were found to be nearly spherical. Changes in characteristics of NPs were not significant after six months of accelerated stability studies. In vivo mucoadhesion study showed significant retention of mucoadhesive NPs in upper gastro-intestinal tract for more than 12 h. Pharmacokinetic study in rats revealed that mucoadhesive NPs could maintain relatively steady plasma concentration of ACV for more than 10 h. The AUC0-∞ and mean residence time of optimised formulation (7527.9 ng h/mL and 12.09 h) were significantly high than tablet dispersion (3841.13 ng h/mL and 7.97 h).

Effective parameters for formulation of gastro adhesive nanoparticles: screening by design-of-experiments approach

The objective of this study was selection of most influential variable for the preparation of gastro adhesive nanoparticles of acyclovir. Effect of formulation and processing variables on various response variables were studied by a Taguchi standard orthogonal array L8 design. Independent variables studied were the amount of gelatin, amount of glutaraldehyde, amount of Pluronic F-68, acetone addition rate, pH, stirring time and stirring speed. The size of all nanoparticulate formulations prepared as per the experimental design (Taguchi screening design) varied between 165 and 1610 nm, PDI between 0.360 and 1.00, Q6 between 7.31-34.93%, T60% between 19.2-37.6 h, entrapment efficiency between 15.70 and 83.12%, loading efficiency between 39.72 and 80.49% and mucoadhesive strength between 3.959-11.02 g. Pareto ranking analyses showed that the two most important factors affecting the selected responses were amount of gelatin and amount of Pluronic F-68 (p < 0.05).

Novel insights into appropriate encapsulation methods for bioactive compounds into polymers: a study with peptides and HDAC inhibitors

The use of different nanoparticles (NPs) for successful encapsulation of bioactive substances is discussed. The inclusion efficiency into liposomes, acetalated dextran (Ac-Dex), and variants of poly[(lactic acid)-co-(glycolic acid)] (PLGA) NPs is analyzed after chemical degradation. Efficient inclusion of SIRT1 inhibitor Ex527 in liposomes, Ac-Dex- and PLGA-NPs is observed for all procedures used. Activity of Ex527 is demonstrated by monitoring the acetylation status of SIRT1-target p53. In contrast, small peptides are only incorporated into acid-terminated PLGA-NPs and marginally into Ac-Dex-NPs. The yield depends on peptide sequence and terminal modifications. Activity is exemplified for angiotensin II using the dynamic mass redistribution technology.

Critical evaluation of biodegradable polymers used in nanodrugs

Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed.

Screening of Most Effective Variables for Development of Gastroretentive Mucoadhesive Nanoparticles by Taguchi Design

The objective of this study was the selection of the most influential variable for the preparation of gastroretentive mucoadhesive nanoparticles of acyclovir. Nanoparticles were prepared by one-step desolvation method; effect of formulation and processing variables on various response variables were studied by a Taguchi standard orthogonal array L8 design. Independent variables studied were the amount of gelatin, amount of glutaraldehyde, amount of Pluronic F-68, acetone addition rate, pH, stirring time, and stirring speed. The dependent variables studied were the particle size, polydispersity index, amount of drug released in 6 h, time required to release 60% of drug, entrapment efficiency, loading efficiency, and mucoadhesiveness. The size of all nanoparticulate formulations prepared as per the experimental design (Taguchi screening design) varied between 165 and 1610 nm, PDI between 0.360 and 1.00, bioadhesiveness between 3.959 and 11.02 g, cumulative percent drug release in 24 h between 40.74 and 72.48, entrapment efficiency between 15.70 and 83.12, and loading efficiency between 39.72 and 80.49. Pareto ranking analyses showed that the two most important factors affecting the selected responses were amount of gelatin and amount of Pluronic F-68 (P<0.05).

Exploration of statistical experimental design to improve entrapment efficiency of acyclovir in poly (d, l) lactide nanoparticles

OBJECTIVE

In current exploration, systematic attempts have been made to improve the entrapment efficiency of a model hydrophilic drug substance, i.e. acyclovir, in poly (d, l) lactide (PLA) nanoparticles (NPs) using a modified nanoprecipitation technique.

METHODS

Formulation parameters such as drug to polymer ratio, antisolvent selection, electrolyte (NaCl) addition, pH alteration and temperature were screened to improve the entrapment efficiency of acyclovir in PLA NPs. The temperature of the system (0-5 °C), phase volume ratio (1:2), stirring speed (2000 rpm), sonication time (5 min), etc. were kept constant during the preparation of NPs. Drug to polymer ratio and electrolyte addition emerged as critical formulation parameters affecting particle size as well as entrapment efficiency. Hence, in the present investigation a 3(2) full factorial design was used to investigate the combined influence of two factors, i.e. drug to polymer ratio (X1) and the amount of electrolyte, i.e. NaCl (X2) on particle size (Y1) and entrapment efficiency (Y2). The NPs were also evaluated for drug-excipient compatibility study by employing DSC and FT-IR analysis, whereas in vitro drug release studies were performed using dialysis bag technique in phosphate buffer pH 7.4.

RESULTS

Statistically significant models were evolved to predict entrapment efficiency and particle size. The effect of factors X1, X2 and [Formula: see text] was found to be statistically significant in nature. Response variables, i.e. entrapment efficiency and particle size, were simultaneously optimized using desirability function using Design Expert software. This process allowed the selection of most suitable level of factors to achieve desired level of particle size and entrapment efficiency. The results of multiple linear regression analysis revealed that for obtaining desirable particle size (less than 250 nm) and entrapment efficiency (more than 17%), the NPs should be prepared using 1:3 drug to polymer ratio and 0.04 M NaCl. Acyclovir was found to be compatible with PLA as indicated by DSC and FT-IR studies. The experimental values obtained from the optimized formulation highly agreed with the predicted values. The drug release from the optimized formulation exhibited biphasic pattern and the drug release kinetics was best explained by Weibull model.

CONCLUSION

In conclusion, results of the present study demonstrated that PLA NPs with expected particle size and entrapment efficiency can be obtained by adopting the concept of quality by design.

Encapsulation of Acyclovir in new carboxylated cyclodextrin-based nanosponges improves the agent's antiviral efficacy

Cyclodextrin-based nanosponges (NS) are solid nanoparticles, obtained from the cross-linking of cyclodextrins that have been proposed as delivery systems for many types of drugs. Various NS derivatives are currently under investigation in order that their properties might be tuned for different applications. In this work, new carboxylated cyclodextrin-based nanosponges (Carb-NS) carrying carboxylic groups within their structure were purposely designed as novel Acyclovir carriers. TEM measurements revealed their spherical shape and size of about 400 nm. The behaviour of Carb-NS, with respect to the incorporation and delivery of Acyclovir, was compared to that of NS, previously investigated as a drug carrier. DSC, XRPD and FTIR analyses were used to investigate the two NS formulations. The results confirm the incorporation of the drug into the NS structure and NS-Acyclovir interactions. The Acyclovir loading into Carb-NS was higher than that obtained using NS, reaching about 70% (w/w). In vitro release studies showed the release kinetics of Acyclovir from Carb-NS to be prolonged in comparison with those observed with NS, with no initial burst effect. The NS uptake into cells was evaluated using fluorescent Carb-NS and revealed the nanoparticle internalisation. Enhanced antiviral activity against a clinical isolate of HSV-1 was obtained using Acyclovir loaded in Carb-NS.