In vitro and in vivo investigation for optimization of niosomal ability for sustainment and bioavailability enhancement of diltiazem after nasal administration

Optimized mucoadhesive niosomal carriers for intranasal delivery of carvedilol: A quality by design approach

Carvedilol (CV), a β-blocker essential for treating cardiovascular diseases, faces bioavailability challenges due to poor water solubility and first-pass metabolism. This study developed and optimized chitosan (CS)-coated niosomes loaded with CV (CS/CV-NS) for intranasal (IN) delivery, aiming to enhance systemic bioavailability. Utilizing a Quality-by-Design (QbD) approach, the study investigated the effects of formulation variables, such as surfactant type, surfactant-to-cholesterol (CHOL) ratio, and CS concentration, on CS/CV-NS properties. The focus was to optimize specific characteristics including particle size (PS), polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (EE%), and mucin binding efficiency (MBE%). The optimal formulation (Opt CS/CV-NS), achieved with a surfactant: CHOL ratio of 0.918 and a CS concentration of 0.062 g/100 mL, using Span 60 as the surfactant, exhibited a PS of 305 nm, PDI of 0.36, ZP of + 33 mV, EE% of 63 %, and MBE% of 57 %. Opt CS/CV-NS was characterized for its morphological and physicochemical properties, evaluated for stability under different storage conditions, and assessed for in vitro drug release profile. Opt CS/CV-NS demonstrated a 1.7-fold and 4.8-fold increase in in vitro CV release after 24 h, compared to uncoated CV-loaded niosomes (Opt CV-NS) and free CV, respectively. In vivo pharmacokinetic (PK) study, using a rat model, demonstrated that Opt CS/CV-NS achieved faster Tmax and higher Cmax compared to free CV suspension indicating enhanced absorption rate. Additionally, Opt CV-NS showed a 1.68-fold higher bioavailability compared to the control. These results underscore the potential of niosomal formulations in enhancing IN delivery of CV, offering an effective strategy for improving drug bioavailability and therapeutic efficacy.

A Comprehensive Review on Niosomes as a Tool for Advanced Drug Delivery

Over the past few decades, advancements in nanocarrier-based therapeutic delivery have been significant, and niosomes research has recently received much interest. The self-assembled nonionic surfactant vesicles lead to the production of niosomes. The most recent nanocarriers, niosomes, are self-assembled vesicles made of nonionic surfactants with or without the proper quantities of cholesterol or other amphiphilic molecules. Because of their durability, low cost of components, largescale production, simple maintenance, and high entrapment efficiency, niosomes are being used more frequently. Additionally, they enhance pharmacokinetics, reduce toxicity, enhance the solubility of poorly water-soluble compounds, & increase bioavailability. One of the most crucial features of niosomes is their controlled release and targeted diffusion, which is utilized for treating cancer, infectious diseases, and other problems. In this review article, we have covered all the fundamental information about niosomes, including preparation techniques, niosomes types, factors influencing their formation, niosomes evaluation, applications, and administration routes, along with recent developments.

Drug delivery methods based on nanotechnology for the treatment of eye diseases

One of the most difficult tasks among the numerous medication delivery methods is ocular drug delivery. Despite having effective medications for treating ocular illness, we have not yet managed to develop an appropriate drug delivery strategy with the fewest side effects. Nanotechnology has the potential to significantly address the drawbacks of current ocular delivery systems, such as their insufficient therapeutic effectiveness and unfavourable side effects from invasive surgery or systemic exposure. The objective of the current research is to highlight and update the most recent developments in nano-based technologies for the detection and treatment of ocular diseases. Even if more work has to be done, the advancements shown here might lead to brand-new, very practical ocular nanomedicines.

Nanotechnology-based ocular drug delivery systems: recent advances and future prospects

Ocular drug delivery has constantly challenged ophthalmologists and drug delivery scientists due to various anatomical and physiological barriers. Static and dynamic ocular barriers prevent the entry of exogenous substances and impede therapeutic agents' active absorption. This review elaborates on the anatomy of the eye and the associated constraints. Followed by an illustration of some common ocular diseases, including glaucoma and their current clinical therapies, emphasizing the significance of drug therapy in treating ocular diseases. Subsequently, advances in ocular drug delivery modalities, especially nanotechnology-based ocular drug delivery systems, are recommended, and some typical research is highlighted. Based on the related research, systematic and comprehensive characterizations of the nanocarriers are summarized, hoping to assist with future research. Besides, we summarize the nanotechnology-based ophthalmic drugs currently on the market or still in clinical trials and the recent patents of nanocarriers. Finally, inspired by current trends and therapeutic concepts, we provide an insight into the challenges faced by novel ocular drug delivery systems and further put forward directions for future research. We hope this review can provide inspiration and motivation for better design and development of novel ophthalmic formulations.

Nanotechnology based drug delivery systems for the treatment of anterior segment eye diseases

Diseases affecting the anterior segment of the eye are the primary causes of vision impairment and blindness globally. Drug administration through the topical ocular route is widely accepted because of its user/patient friendliness - ease of administration and convenience. However, it remains a significant challenge to efficiently deliver drugs to the eye through this route because of various structural and physiological constraints that restrict the distribution of therapeutic molecules into the ocular tissues. The bioavailability of topically applied ocular medications such as eye drops is typically less than 5%. Developing novel delivery systems to increase the retention time on the ocular surfaces and permeation through the cornea is one of the approaches adopted to boost the bioavailability of topically administered medications. Drug delivery systems based on nanotechnology such as micelles, nanosuspensions, nanoparticles, nanoemulsions, liposomes, dendrimers, niosomes, cubosomes and nanowafers have been investigated as effective alternatives to conventional ocular delivery systems in treating diseases of the anterior segment of the eye. This review discussed different nanotechnology-based delivery systems that are currently investigated for treating and managing diseases affecting the anterior ocular tissues. We also looked at the challenges in translating these systems into clinical use and the prospects of nanocarriers as a vehicle for the delivery of phytoactive compounds to the anterior segment of the eye.

Convolution- and Deconvolution-Based Approaches for Prediction of Pharmacokinetic Parameters of Diltiazem Extended-Release Products in Flow-Through Cell Dissolution Tester

The present study evaluated the effect of different configuration setups of the Flow-Through Cell (USP IV) dissolution tester in developing in vitro-in vivo correlation (IVIVC). A Biopharmaceutics Classification System (BCS) Class I Diltiazem (DTZ), formulated in extended-release (ER) gel-matrix system, was employed for this purpose. The study also assessed the validity and predictability of IVIVC employing both deconvolution- and convolution-based approaches. In vitro release was conducted in USP IV as open- or closed-loop setups, while the pharmacokinetic (PK) data were obtained from a previous fasted-state cross-over study conducted on 8 healthy male volunteers, after oral administration of ER matrix tablets against market product (Tildiem Retard® 90 mg). PK parameters (C_max, AUC_0-t and AUC_0-∞) were predicted, and compared with actual data to establish the strength of correlation models. Results showed that DTZ release from ER products was influenced by operating the FTC in different configuration-setups, where ≥ 75% of labeled DTZ was released after 6 h and 12 h using the open- and closed-loop settings, respectively. Correlation between fraction-dissolved versus fraction-absorbed for both ER products displayed linear relation upon employing FTC open-loop setup. Convolution-based approach was more discriminative in predicting DTZ in vivo PK parameters with a minimal prediction error, compared to deconvolution-based approach. A successful trial to predict DTZ PKs from individual in vitro data performed in USP IV dissolution model was established, employing convolution technique. Basic principle of the convolution approach provides a simple and practical method for developing IVIVC, hence could be utilized for other BCS Class I extended-release drug products.

Augmented in vitro and in vivo Profiles of Brimonidine Tartrate Using Gelatinized-Core Liposomes

Background

The low entrapment efficiency of the hydrophilic drugs such as brimonidine tartrate (BRT) in liposomes represents a challenge that requires interventions. Gelatinized core liposomes (GCLs) were fabricated to increase the drug entrapment, corneal penetration, and physical stability of the investigated molecule.

Research Design and Methods

GCLs encapsulating BRT were prepared and optimized utilizing D-optimal design (DOD). The effect of plasticizer incorporation on the physicochemical characteristics and on the in vivo performance was studied. The optimized formulations were investigated for pH, rheological properties, morphological characteristics, in vitro release profiles, biological performance, safety profile. The effects of storage and gamma sterilization were also investigated.

Results

The results revealed the great success of the prepared formulations to achieve high entrapment efficiency reaching 98% after a maturation period of 10 days. The addition of glycerol as plasticizer significantly minimized the particle size and shortened the maturation period to 7 days. The selected formulations were stable for 3 months after gamma sterilization. The formulations showed significant lowering of intra-ocular pressure (IOP) in glaucomatous rabbits with sustainment of the pharmacological effect for 24 hours compared to drug solution.

Conclusions

Enhanced in vitro and in vivo profiles of brimonidine tartrate loaded gelatinized-core-liposomes were obtained.

Enhancement of Anti-Inflammatory Activity of Optimized Niosomal Colchicine Loaded into Jojoba Oil-Based Emulgel Using Response Surface Methodology

Recent progression in investigational studies aiming to integrate natural products and plant oils in developing new dosage forms that would provide optimal therapeutic effect. Therefore, the aim of the present exploration was to inspect the influence of jojoba oil in boosting the anti-inflammatory effect of colchicine natural product. To our knowledge, there is no formulation comprising colchicine and jojoba oil together to form a niosomal emulgel preparation anticipated for topical application. Colchicine is a natural product extracted from Colchicum autumnale that has been evidenced to show respectable anti-inflammatory activity. Owing to its drawbacks and low therapeutic index, it was preferable to be formulated into topical dosage form. The current study inspected colchicine transdermal delivery by developing niosomal preparation as a potential nanocarrier included into emulgel prepared with jojoba oil. Box Behnken design was constructed to develop 17 niosomal emulgel formulations. The optimized colchicine niosomal emulgel was evaluated for its physical characteristics and in vitro release studies. The in vivo anti-inflammatory activity was estimated via carrageenan-induced rat hind paw edema method. The developed colchicine niosomal preparation revealed particle size of 220.7 nm with PDI value 0.22, entrapment efficiency 65.3%. The formulation was found to be stable showing no significant difference in particle size and entrapment efficiency up on storage at 4 °C and 25 °C for 3 months. The optimized colchicine niosomal emulgel exhibited a pH value 6.73, viscosity 4598 cP, and spreadability 38.3 mm. In vitro release study of colchicine from niosomal emulgel formulation was around 52.4% over 6 h. Apparently, the proficient anti-inflammatory activity of colchicine niosomal emulgel was confirmed via carrageenan-induced rat hind paw edema test. Overall, the results recommend the combination of niosomal preparation with jojoba oil-based emulgel that might signify a favorable delivery of anti-inflammatory drug such as colchicine.

The Impact of Improving Dermal Permeation on the Efficacy and Targeting of Liposome Nanoparticles as a Potential Treatment for Breast Cancer

Breast cancer is the most frequent malignancy in women. This work focuses on developing deformable liposomes as a potential carrier for breast cancer treatment and studying the impact of improving dermal permeation on the efficacy and targeting of liposomes. Raloxifene (RXF), an oestrogen antagonist, was used as a model drug. Using Box-Behnken design, different formulations of RXF-loaded deformable liposome (RLDL) were prepared using different propylene glycol, phospholipid and cholesterol concentrations. The percentage of entrapment efficiency (Y₁), particle size (Y₂), zeta potential (Y₃) and steady-state flux (Y₄) of the prepared formulations were all evaluated. Y₁ and Y₄ were significantly increased and Y₂ and Y₃ were significantly decreased when the propylene glycol concentration was increased. The optimization was obtained and the optimum formulation was that including phospholipid (1.40% w/w), cholesterol (0.15% w/w) and propylene glycol (10% v/v). The selected optimum formulation displayed a % EE of 78.34 ± 1.04% with a steady-state flux of 4.21 ± 0.02 µg/cm²/h. In order to investigate bioavailability, antitumor effectiveness and permeation, the optimum formulation was selected and included in a carbopol gel. The optimum gel formulation had 2.77 times higher bioavailability and, as a result, considerable antitumor action as compared to oral RXF. In conclusion, optimum RLDL gel may be an effective breast cancer treatment.

Improving the Antitumor Activity and Bioavailability of Sonidegib for the Treatment of Skin Cancer

Throughout the United States and the world, skin cancer is the most frequent form of cancer. Sonidegib (SNG) is a hedgehog inhibitor that has been used for skin cancer treatment. However, SNG has low bioavailability and is associated with resistance. The focus of this work is to enhance bioavailability, anti-tumor efficacy and targeting of SNG via developing ethosome gel as a potential treatment for skin cancer. SNG-loaded ethosomes formulation was prepared and characterized in vitro by %entrapment efficiency (%EE), vesicle size, morphology, %release and steady-state flux. The results showed that the prepared formulation was spherical nanovesicles with a %EE of 85.4 ± 0.57%, a particle size of 199.53 ± 4.51 nm and a steady-state flux of 5.58 ± 0.08 µg/cm2/h. In addition, SNG-loaded ethosomes formulation was incorporated into carbopol gel to study the anti-tumor efficacy, localization and bioavailability in vivo. Compared with oral SNG, the formulation showed 3.18 times higher relative bioavailability and consequently significant anti-tumor activity. In addition, this formulation showed a higher rate of SNG penetration in the skin's deep layers and passive targeting in tumor cells. Briefly, SNG-loaded ethosome gel can produce desirable therapeutic benefits for treatment of skin cancer.

A Novel Calcium Channel Blocker: Etripamil: What is the Future of Intranasal Drug Delivery in the Treatment of Cardiac Arrhythmias?

Symptomatic paroxysmal cardiac arrhythmias are common cardiac conditions that lead to a decreased quality of life, increased healthcare costs, and significant morbidity. Many cardiac arrhythmias increase in frequency with age, and as the elderly population continues to increase, so will the incidence and prevalence of cardiac arrhythmias. The long-term treatment options for patients with paroxysmal arrhythmias include ablation procedures and daily oral antiarrhythmics. Acute management entails vagal maneuvers, intravenous antiarrhythmics, and synchronized cardioversion. However, there are limited treatment options for patients with less frequent and less severe arrhythmias, ablation refractory disease, or who are poor candidates for ablative procedures, For abortive therapy, oral anti-arrhythmic medications are ineffective due to their slow onset of action and intravenous medications require treatment at an acute care facility, which is both costly and stressful to the patient. Etripamil is a novel intranasal non-dihydropyridine calcium channel blocker that has begun phase III clinical trials for the treatment of paroxysmal supraventricular tachycardias. Due to its intranasal mode of delivery, etripamil has a rapid onset of action, and could feasibly be administered by the patient themselves. Clinical phase II trials of etripamil in moderate to high doses demonstrated efficacy comparable to the standard of care, and took an average of 3 minutes from drug administration to conversion to sinus rhythm. In this article, we have conducted an extensive literature review of intranasal drug delivery, calcium channel blockers, and etripamil, to discuss the future possibilities of using this new medication.

Quantitative analysis of inulin distribution in the brain focused on nose-to-brain route via olfactory epithelium by reverse esophageal cannulation

This study aimed to determine the effect of intranasal dosing speed and administrating volume of nose-to-brain delivery on candidates for peptide drugs (molecular weight ca. 1-10 kDa). Using inulin as the model molecule of a peptide drug, intranasal administration by cannulation from the airway side through the esophagus was tested in mice. This was done to determine the quantitative distribution levels of the drug in the brain and cerebral spinal fluid (CSF). Distribution levels were increased with slower and constant speed (5 μL/min), with higher dosing volume equivalent to nasal volume per body weight in mice (25 μL), and were recorded 0.27% injected dose per gram of tissue (ID/g) in the brain, and 0.24% injected dose per milliliter (ID/mL) in the CSF at 60 min. Then, brain distribution resulting from reverse cannulation was two times more than that of the typical intranasal administration method using a micropipette. In addition, the percentage of inulin estimated to reach the brain via direct transport (%DTP) during reverse cannulation was estimated to be 93%, suggesting that ~95% of the total dose was transferred directly to the brain via the olfactory mucosa. These results show that distribution of the peptide drug in the brain was increased through constant administration at a slow and constant speed.

Directly Compressed Tablets: A Novel Drug-Containing Reservoir Combined with Hydrogel-Forming Microneedle Arrays for Transdermal Drug Delivery

Microneedle (MN) patches consist of a hydrogel-forming MN array and a drug-containing reservoir. Drug-containing reservoirs documented in the literature include polymeric films and lyophilized wafers. While effective, both reservoir formulations are aqueous based, and so degradation can occur during formulation and drying for drugs inherently unstable in aqueous media. The preparation and characterization of novel, nonaqueous-based, directly compressed tablets (DCTs) for use in combination with hydrogel-forming MN arrays are described for the first time. In this work, a range of drug molecules are investigated. Precipitation of amoxicillin (AMX) and primaquine (PQ) in conventional hydrogel-forming MN arrays leads to use of poly(vinyl alcohol)-based MN arrays. Following in vitro permeation studies, in vivo pharmacokinetic studies are conducted in rats with MN patches containing AMX, levodopa/carbidopa (LD/CD), and levofloxacin (LVX). Therapeutically relevant concentrations of AMX (≥2 µg mL^-1 ), LD (≥0.5 µg mL^-1 ), and LVX (≥0.2 µg mL^-1 ) are successfully achieved at 1, 2, and 1 h, respectively. Thus, the use of DCTs offers promise to expand the range of drug molecules that can be delivered transdermally using MN patches.

Development of Provesicular Nanodelivery System of Curcumin as a Safe and Effective Antiviral Agent: Statistical Optimization, In Vitro Characterization, and Antiviral Effectiveness

Curcumin is a natural compound that has many medical applications. However, its low solubility and poor stability could impede its clinical applications. The present study aimed to formulate dry proniosomes to overcome these pitfalls and improve the therapeutic efficacy of Curcumin. Curcumin-loaded proniosomes were fabricated by the slurry method according to 32 factorial design using Design-Expert software to demonstrate the impact of different independent variables on entrapment efficiency (EE%) and % drug released after 12 h (Q12h). The optimized formula (F5) was selected according to the desirability criteria. F5 exhibited good flowability and appeared, after reconstitution, as spherical nanovesicles with EE% of 89.94 ± 2.31% and Q12h of 70.89 ± 1.62%. F5 demonstrated higher stability and a significant enhancement of Q12h than the corresponding niosomes. The docking study investigated the ability of Curcumin to bind effectively with the active site of DNA polymerase of Herpes simplex virus (HSV). The antiviral activity and the safety of F5 were significantly higher than Curcumin. F5 improved the safety of Acyclovir (ACV) and reduced its effective dose that produced a 100% reduction of viral plaques. Proniosomes could be promising stable carriers of Curcumin to be used as a safe and efficient antiviral agent.

Glaucoma: Management and Future Perspectives for Nanotechnology-Based Treatment Modalities

Glaucoma, being asymptomatic for relatively late stage, is recognized as a worldwide cause of irreversible vision loss. The eye is an impervious organ that exhibits natural anatomical and physiological barriers which renders the design of an efficient ocular delivery system a formidable task and challenge scientists to find alternative formulation approaches. In the field of glaucoma treatment, smart delivery systems for targeting have aroused interest in the topical ocular delivery field owing to its potentiality to oppress many treatment challenges associated with many of glaucoma types. The current momentum of nano-pharmaceuticals, in the development of advanced drug delivery systems, hold promises for much improved therapies for glaucoma to reduce its impact on vision loss. In this review, a brief about glaucoma; its etiology, predisposing factors and different treatment modalities has been reviewed. The diverse ocular drug delivery systems currently available or under investigations have been presented. Additionally, future foreseeing of new drug delivery systems that may represent potential means for more efficient glaucoma management are overviewed. Finally, a gab-analysis for the required investigation to pave the road for commercialization of ocular novel-delivery systems based on the nano-technology are discussed.

Proniosomal Microcarriers: Impact of Constituents on the Physicochemical Properties of Proniosomes as a New Approach to Enhance Inhalation Efficiency of Dry Powder Inhalers

Proniosomes are free-flowing systems with coating carriers, which developed as a method for improving the drug flow and pulmonary delivery. Extensive research on proniosomes was done to enhance the dry powder inhalers (DPI)'s inhalation performance. This research aimed at studying the impact of lactose-mannitol mixture additives on the proniosome's physicochemical properties as a method for improving the inhalation efficiency of DPI. Vismodegib has been employed as a compound model. Box-Behnken design has been employed to prepare different proniosomes formulae by incorporating various (A) span 60 concentrations, (B) lactose concentrations and (C) mannitol: total carrier mixture. The measured responses were vesicle size (R₁), %release (R₂), Carr's index (R₃) and %recovery (R₄). The results displayed that R₁ and R₄ were significantly antagonistic to C and significantly synergistic to both A and B while R₂ and R₃ were significantly synergistic to C and significantly antagonistic to both A and B. The optimal formula was selected for its aerodynamic behaviour, cytotoxic activity and bioavailability assessment. The optimal formula resulted in better Vismodegib lung deposition, cytotoxic activity and relative bioavailability. This novel formula could be a promising carrier for sustained delivery of drugs via the pulmonary route.

Formulation and evaluation of niosomal vesicles containing ondansetron HCL for trans-mucosal nasal drug delivery

Ondansetron HCl is a (5-HT3) serotonin receptor antagonist, used as anti-emetic drug in combination with anticancer agents. Conventional dosage forms have poor bioavailability and patient compliance. These problems can be reduced by the use of nasal niosomal thermo-reversible in situ gelling system. Niosomes were formulated using various surfactants (Span 60, Span 80, Tween 20, and Tween 80) in different ratios using the thin-film hydration technique. Niosomes were evaluated for particle size, zeta potential, transmission electron microscopy (TEM) imaging, drug entrapment efficiency, and in vitro drug release. Niosomes prepared using Span 60 and cholesterol in the ratio 1:1 (F5) showed higher entrapment efficiency (76.13 ± 1.2%) and in vitro drug release (91.76%) after 12 h was optimized. The optimized niosomes were developed into thermo-reversible in situ gel, composed of Poloxamer 407 and sodium carboxymethyl cellulose, prepared by cold method technique. Compatibility study (FTIR, DSC) was made for drugs and excipients that showed no significant interaction. The gel formulation G5 showed the most suitable gelation temperature (31 °C), viscosity (1250 mpoise), bioadhesion force (5860 ± 28 dyne/cm²), and in vitro drug release (70.6%) after 12 h. Comparative in vivo pharmacokinetic study on rabbits showed a sustained release and higher relative bioavailability of the prepared nasal in situ gel compared to similar dose of oral tablets (202.4%) which make ondansetron HCl niosomal nasal thermo-sensitive in situ gel a more convenient dosage form for the administration of ondansetron HCl than oral tablets.

Intranasal Nanoparticulate Systems as Alternative Route of Drug Delivery

There is always a need for alternative and efficient methods of drug delivery. The nasal cavity can be considered as a non-invasive and efficient route of administration. It has been used for local, systemic, brain targeting, and vaccination delivery. Although many intranasal products are currently available on the market, the majority is used for local delivery with fewer products available for the other targets. As nanotechnology utilization in drug delivery has rapidly spread out, the nasal delivery has become attractive as a promising approach. Nanoparticulate systems facilitate drug transportation across the mucosal barrier, protect the drug from nasal enzyme degradation, enhance the delivery of vaccines to the lymphoid tissue of the nasal cavity with an adjuvant activity, and offer a way for peptide delivery into the brain and the systemic circulation, in addition to their potential for brain tumor treatment. This review article aims at discussing the potential benefit of the intranasal nanoparticulate systems, including nanosuspensions, lipid and surfactant, and polymer-based nanoparticles as regards productive intranasal delivery. The aim of this review is to focus on the topicalities of nanotechnology applications for intranasal delivery of local, systemic, brain, and vaccination purposes during the last decade, referring to the factors affecting delivery, regulatory aspects, and patient expectations. This review further identifies the benefits of applying the Quality by Design approaches (QbD) in product development. According to the reported studies on nanotechnology-based intranasal delivery, potential attention has been focused on brain targeting and vaccine delivery with promising outcomes. Despite the significant research effort in this field, nanoparticle-based products for intranasal delivery are not available. Thus, further efforts are required to promote the introduction of intranasal nanoparticulate products that can meet the requirements of regulatory affairs with high patient acceptance.

Proniosomal gel-derived niosomes: an approach to sustain and improve the ocular delivery of brimonidine tartrate; formulation, in-vitro characterization, and in-vivo pharmacodynamic study

Brimonidine tartrate (BRT) is a hydrophilic α2 adrenergic agonist used for the treatment of glaucoma. Glaucoma is an ocular disease affecting the anterior segment of the eye requiring lifetime treatment. Owing to the obstacles facing ocular delivery systems and hydrophilicity of BRT, frequent administration of the eye drops is required. Niosomes have been widely used to improve the ocular bioavailability of the topically applied drugs and to enhance the ocular residence time. However, they have drawbacks as physical instability, aggregation, and loss of the entrapped drug. For this reason, BRT proniosomes were prepared to overcome niosomal instability issues. A D-optimal design was utilized to determine the optimum conditions for preparation of the proniosomal gels. Independent variables were amount of surfactant, surfactant:cholesterol ratio, and type of surfactant used. The dependent variables were entrapment efficiency (EE%), particle size, percentage of drug released after 2 h (Q2h), and percentage of drug released after 24 h (Q24h). The optimum formula was suggested with desirability 0.732 and the composition of 540 mg Span 60 and 10:1 surfactant:cholesterol ratio. The results obtained after reconstitution were; EE% of 79.23 ± 1.12% particle size of 810.95 ± 16.758 nm, polydispersity index (PDI) 0.6785 ± 0.213, zeta potential 59.1 ± 0.99 mV, Q2h40.98 ± 1.29%, Q8h 63.35 ± 6.07%, and Q24h = 91.11 ± 1.76%. Transmission electron microscope imaging of the formula showed the typical spherical shape of niosomes. In-vivo pharmacodynamic study assured the improved ocular bioavailability of BRT selected formula when compared with Alphagan®P with relative AUC0-24 of 5.024 and 7.90 folds increase in the mean residence time (MRT). Lack of ocular irritation of the formula was assured by Draize test.

Nanosized Transferosome-Based Intranasal In Situ Gel for Brain Targeting of Resveratrol: Formulation, Optimization, In Vitro Evaluation, and In Vivo Pharmacokinetic Study

Resveratrol (RES) is a potent antioxidant used for the management of several central nervous system diseases. RES bioavailability is less than 1 owing to its low solubility and extensive intestinal and hepatic metabolism. The aim of the study was to enhance RES bioavailability through developing intranasal transferosomal mucoadhesive gel. Reverse evaporation-vortexing sonication method was employed to prepare RES-loaded transferosomes. Transferosomes were developed via 3⁴ definitive screening design, using soya lecithin, permeation enhancers, and surfactants. The optimized formula displayed spherical shape with vesicle size of 83.79 ± 2.54 nm and entrapment efficiency (EE%) of 72.58 ± 4.51%. Mucoadhesive gels were prepared and evaluated, then optimized RES transferosomes were incorporated into the selected gel and characterized using FTIR spectroscopy, in vitro release, and ex vivo permeation study. Histopathological examination of nasal mucosa and in vivo pharmacokinetic study were conducted. In vitro drug release from transferosomal gel was 65.87 ± 2.12% and ex vivo permeation was 75.95 ± 3.19%. Histopathological study confirmed the safety of the optimized formula. The C_max of RES in the optimized RES trans-gel was 2.15 times higher than the oral RES suspension and AUC_(0-∞) increased by 22.5 times. The optimized RES trans-gel developed intranasal safety and bioavailability enhancement through passing hepatic and intestinal metabolism.

Intranasal niosomes of nefopam with improved bioavailability: preparation, optimization, and in-vivo evaluation

OBJECTIVE

One of the greatest challenges drug formulation is facing is poor bioavailability via oral route. In this regard, nasal drug delivery has been commonly used as an alternative route to improve drug bioavailability. Nefopam hydrochloride (NF) is an analgesic drug that suffers from poor bioavailability due to extensive metabolism in liver. Accordingly, the goal of the present study was to improve NF bioavailability via niosomal-based formulation designed for intranasal delivery.

MATERIALS AND METHODS

Vesicles were developed by mixing surfactants (Span 20, Span 40, Span 80, and Span 85) at four molar ratios of 1:1, 1:2, 1:3, and 1:4 of cholesterol to surfactant. Entrapment efficiency, particle size, zeta potential, release percentage, ex-vivo permeation parameters, and niosomes' stability were determined. Also, the pharmacokinetic parameters of the optimized formula in in-situ gel base were measured in rats.

RESULTS

Niosomes showed entrapment efficiency .80%, particle size ,550 nm, and zeta potential ranging from -16.8±0.13 to -29.7±0.15. The produced vesicles showed significantly higher amounts of drug permeated across nasal mucosa (2.5 folds) and prolonged NF release compared with NF solution. Stability studies of optimum formula showed nonsignificant changes in niosomes parameters over a storage period of 6 months. The in-vivo studies showed a 4.77-fold increase in bioavailability of optimized nasal niosomes compared with oral solution of drug.

CONCLUSION

The obtained results revealed the great ability of the produced NF-loaded nio-somes to enhance drug penetration through nasal mucosa and improve its relative bioavailability compared with NF oral solution.

Nano-scale drug delivery systems for antiarrhythmic agents

Arrhythmia means the heart is beating too fast, too slow, or with an irregular pattern. Due to the side effects and low bioavailability of many antiarrhythmic drugs, nano-encapsulation has been widely used for their targeted delivery. Lipid nanocapsules, nano liposomes, nano niosomes, solid lipid nanoparticles and polymeric nanoparticles are common nano-carriers used for this purpose. The aim of this article is to summarize some of nano systems used for the specific delivery of antiarrhythmic agents to target tissues. At first, nanotechnology and its applications in drug delivery are described in brief. Then, some information on arrhythmias and antiarrhythmic drugs are provided. Finally, the nano drug delivery systems are explained and examples of their applications in encapsulation of antiarrhythmic drugs are presented.

Delivery of Oxytocin to the Brain for the Treatment of Autism Spectrum Disorder by Nasal Application

Oxytocin (OXT) is a cyclic nonapeptide, two amino acids of which are cysteine, forming an intramolecular disulfide bond. OXT is produced in the hypothalamus and is secreted into the bloodstream from the posterior pituitary. As recent studies have suggested that OXT is a neurotransmitter exhibiting central effects important for social deficits, it has drawn much attention as a drug candidate for the treatment of autism. Although human-stage clinical trials of the nasal spray of OXT for the treatment of autism have already begun, few studies have examined the pharmacokinetics and brain distribution of OXT after nasal application. The aim of this study is to evaluate the disposition, nasal absorption, and therapeutic potential of OXT after nasal administration. The pharmacokinetics of OXT after intravenous bolus injection to rats followed a two-compartment model, with a rapid initial half-life of 3 min. The nasal bioavailability of OXT was approximately 2%. The brain concentration of OXT after nasal application was much higher than that after intravenous application, despite much lower concentrations in the plasma. More than 95% of OXT in the brain was directly transported from the nasal cavity. The in vivo stress-relief effect by OXT was observed only after intranasal administration. These results indicate that pharmacologically active OXT was effectively delivered to the brain after intranasal administration. In conclusion, the nasal cavity is a promising route for the efficient delivery of OXT to the brain.