Thermoreversible nanoethosomal gel for the intranasal delivery of Eletriptan hydrobromide

Versatile Nanoparticulate Systems as a Prosperous Platform for Targeted Nose-Brain Drug Delivery

The intranasal route has proven to be a reliable and promising route for delivering therapeutics to the central nervous system (CNS), averting the blood-brain barrier (BBB) and avoiding extensive first-pass metabolism of some drugs, with minimal systemic exposure. This is considered to be the main problem associated with other routes of drug delivery such as oral, parenteral, and transdermal, among other administration methods. The intranasal route maximizes drug bioavailability, particularly those susceptible to enzymatic degradation such as peptides and proteins. This review will stipulate an overview of the intranasal route as a channel for drug delivery, including its benefits and drawbacks, as well as different mechanisms of CNS drug targeting using nanoparticulate drug delivery systems devices; it also focuses on pharmaceutical dosage forms such as drops, sprays, or gels via the nasal route comprising different polymers, absorption promoters, CNS ligands, and permeation enhancers.

Nanovesicular-Mediated Intranasal Drug Therapy for Neurodegenerative Disease

Numerous neurodegenerative conditions, such as Alzheimer's, Huntington's, Parkinson's, amyotrophic lateral sclerosis, and glioblastoma multiform are now becoming significant concerns of global health. Formulation-related issues, physiological and anatomical barriers, post-administration obstacles, physical challenges, regulatory limitations, environmental hurdles, and health and safety issues have all hindered successful delivery and effective outcomes despite a variety of treatment options. In the current review, we covered the intranasal route, an alternative strategic route targeting brain for improved delivery across the BBB. The trans-nasal pathway is non-invasive, directing therapeutics directly towards brain, circumventing the barrier and reducing peripheral exposure. The delivery of nanosized vesicles loaded with drugs was also covered in the review. Nanovesicle systems are organised in concentric bilayered lipid membranes separated with aqueous layers. These carriers surmount the disadvantages posed by intranasal delivery of rapid mucociliary clearance and enzymatic degradation, and enhance retention of drug to reach the site of target. In conclusion, the review covers in-depth conclusions on numerous aspects of formulation of drug-loaded vesicular system delivery across BBB, current marketed nasal devices, significant jeopardies, potential therapeutic aids, and current advancements followed by future perspectives.

Advances and challenges in nintedanib drug delivery

INTRODUCTION

Nintedanib (N.T.B) is an orally administered tyrosine kinase inhibitor that has been approved recently by U.S.F.D.A for idiopathic pulmonary fibrosis (I.P.F) and systemic sclerosis-associated interstitial lung disease (S.Sc-I.L.D). N.T.B is also prescribed in COVID-19 patients associated with I.P.F. However, it has an extremely low bioavailability of around 4.7%, and hence, researchers are attempting to address this drawback by different approaches.

AREAS COVERED

This review article focuses on enlisting all the formulation attempts explored by researchers to increase the bioavailability of N.T.B while also providing meaningful insight into the unexplored areas in formulation development, such as targeting of the lymphatic system and transdermal delivery. All the patents on the formulation development of N.T.B have also been summarized.

EXPERT OPINION

N.T.B has the potential to act on multiple diseases that are still being discovered, but its extremely low bioavailability is a challenge that is to be dealt with for obtaining the full benefit. Few studies have been performed aiming at improving the bioavailability, but there are unexplored areas that can be used, a few of which are explained in this article. However, the ability to reproduce laboratory results when scaling up to the industry level is the only factor to be taken into consideration.

Formulation and Evaluation of Resveratrol Loaded Cubosomal Nanoformulation for Topical Delivery

AIM

The aim of the study was to formulate, characterize, and evaluate the Resveratrol- loaded Cubosomes (RC) for topical application.

BACKGROUND

Resveratrol (RV) is a nutraceutical compound with exciting pharmacological potential in different diseases, including cancers. Many studies on resveratrol have been reported for anti- melanoma activity. Due to its low bioavailability, the therapeutic activities of resveratrol are strongly limited. Hence, an approach with nanotechnology has been made to increase its activity through transdermal drug delivery.

OBJECTIVE

To formulate, characterize, and evaluate the resveratrol-loaded cubosomes (RC). To evaluate Resveratrol-loaded Cubosomal Gel (RC-Gel) for its topical application.

METHODS

RC was formulated by homogenization technique and optimized using a 2-factor 3-level factorial design. Formulated RCs were characterized for particle size, zeta potential, and entrapment efficiency. Optimized RC was evaluated for in vitro release and stability study. Optimized RC was further formulated into cubosomal gel (RC-Gel) using carbopol and evaluated for drug permeation and deposition. Furthermore, developed RC-Gel was evaluated for its topical application using skin irritancy, toxicity, and in vivo local bioavailability studies.

RESULTS

The optimized RC indicated cubic-shaped structure with mean particle size, entrapment efficiency, and zeta potential were 113±2.36 nm, 85.07 ± 0.91%, and -27.40 ± 1.40 mV, respectively. In vitro drug release of optimized RC demonstrated biphasic drug release with the diffusion-controlled release of resveratrol (RV) (87.20 ± 3.91%). The RC-Gel demonstrated better drug permeation and deposition in mice skin layers. The composition of RC-Gel has been proved non-irritant to mice skin. In vivo local bioavailability study depicted the good potential of RC-Gel for skin localization.

CONCLUSION

The RC nanoformulation proposes a promising drug delivery system for melanoma treatment simply through topical application.

Coenzyme Q10 phospholipidic vesicular formulations for treatment of androgenic alopecia: ex vivo permeation and clinical appraisal

INTRODUCTION

Coenzyme Q10 (CoQ10) is an antioxidant molecule with anti-aging activity on human hair, and because of its pharmaceutical limitations such as large molecular weight, high lipophilicity and poor water solubility, its therapeutic effectiveness has been hampered. Therefore, different vesicular nanocarriers were developed in the current work, for enhancement of the skin penetration of CoQ10 for treatment of androgenic alopecia.

AREAS COVERED

In order to overcome the poor skin penetration of CoQ10, it was formulated in liposomes, transfersomes, ethosomes, cerosomes and transethosomes using the thin-film hydration method. Results revealed that transethosomes were the carrier of choice for CoQ10, in which it displayed a particle size of 146 nm, zeta potential -55 mV and entrapment efficiency of 97.63%. Transethosomes also achieved the highest deposition percentage for CoQ10, exceeding 95% in the different skin layers. Upon clinical examination in patients suffering from androgenic alopecia, CoQ10 transethosomes displayed better clinical response than the administration of CoQ10 solution, which was further confirmed by dermoscopic examination.

EXPERT OPINION

Findings of this study further prove that loading antioxidants such as CoQ10 in nanocarriers maximizes their therapeutic efficiency, and opens many opportunities for their application in treatment of several other topical diseases.

Intranasal In Situ Gel of Apixaban-Loaded Nanoethosomes: Preparation, Optimization, and In Vivo Evaluation

The present study was conducted to formulate ethosomal thermoreversible in situ gel of apixaban, an anticoagulant drug, for nasal delivery. Ethosomes were formed, of lecithin, cholesterol, and ethanol, by using thin-film hydration method. The prepared ethosomes were characterized by Zetasizer, transmission electron microscope, entrapment efficiency, and in vitro study. The selected ethosomal formula (API-ETHO2) was incorporated in gel using P407 and P188 as thermoreversible agents and carbopol 934 as mucoadhesive agent. Box-Behnken design was used to study the effect of independent variables (concentration of P407, P188, and carbopol 934) on gelation temperature, mucoadhesive strength, and in vitro cumulative percent drug released at 12h (response variables). The optimized formulation was subjected to compatibility study, ex vivo permeation, histopathological examination for the nasal mucosa, and in vivo study. API-ETHO2 was spherical with an average size of 145.1±12.3 nm, zeta potential of -20±4 mV, entrapment efficiency of 67.11%±3.26, and in vitro % release of 79.54%±4.1. All gel formulations exhibited an acceptable pH and drug content. The optimum gel offered 32.3°C, 1226.3 dyne/cm², and 53.50% for gelation temperature, mucoadhesive strength, and in vitro percent released, respectively. Apixaban ethosomal in situ gel evolved higher ex vivo permeation (1.499±0.11 μg/cm²h) through the nasal mucosa than pure apixaban gel. Histopathological study assured that there is no necrosis or tearing of the nasal mucosa happened by ethosomal gel. The pharmacokinetic parameters in rabbit plasma showed that intranasal administration of optimized API-ethosomal in situ gel achieved higher C_max and AUC_0-∞ than unprocessed API nasal gel, nasal suspension, and oral suspension. The ethosomal thermoreversible nasal gel established its potential to improve nasal permeation and prolong anticoagulant effect of apixaban.

Development, evaluation and biodistribution of stealth liposomes of 5-fluorouracil for effective treatment of breast cancer

The current research was undertaken to design stealth liposomes of 5-Fluorouracil for reducing its cardiotoxicity and prolong the half-life by developing long-circulating liposomes. The liposomes were prepared by the NH₄EDTA gradient method, where EDTA is used as a cardioprotectant. Ascorbyl-6-palmitate was also used which helped for the synergistic effect of 5-Fluorouracil to counteract the cancer cells and provide promising application in the treatment of breast cancer cells. Taguchi design was used for screening of formulation and HSPC phospholipid was selected. The drug-excipient compatibility was checked through FTIR which showed all the excipients were compatible with the drug. The formulation was optimized by using 3² factorial design. The drug to lipid ratio (1:5) and Ascorbyl-6-Palmitate concentration (15 mg) were selected. The vesicle size of the prepared liposomes was found to be 70.12 ± 0.58 nm and uniform distribution was observed. The zeta potential and entrapment efficiency of the stealth liposomes were found -16.28 mV and 92 ± 0.007% respectively. In-vitro drug release study of formulation showed drug release of 63.50 ± 0.94% in 24 hrs. The formulation was sterilized by 0.22 µm Mixed cellulose esters (MCE) membrane filter and passed sterility test. Moreover, a biodistribution study was performed by Fluorescence microscopy and by HPLC method, which showed formulation was circulated for 24 hours. Finally, a cell line study indicated that prepared formulation possess greater anti-tumour activity. The cardiotoxicity study revealed that the stealth liposomes have minimum cardiotoxicity as compare to the plain drug.

Enhanced brain targeting efficiency using 5-FU (fluorouracil) lipid-drug conjugated nanoparticles in brain cancer therapy

The present investigation was aimed to synthesize, optimize, and characterize lipid/drug conjugate nanoparticles for delivering 5-fluorouracil (5-FU) to treat brain cancer. The Box-Behnken design was used to optimize the formulation, evaluate the particle size, entrapment efficiency, morphology, in vitro drug release study, and stability profiles. The in vitro performance was executed using cell line studies. The in vivo performance was carried out for pharmacokinetic studies, sterility test, biodistribution studies, and distribution lipid-drug conjugated (LDC) nanoparticles in the brain. Particle size, zeta potential, entrapment efficiency, and morphology of the optimized formulation demonstrated desirable results. In vitro release pattern showed initial fast release, followed by sustained release up to 48 h. Cytotoxic effects of blank stearic acid nanoparticles, LDC nanoparticles, and 5-FU solution on human glioma cell lines U373 MG cell showed more cytotoxicity by LDC-NPs compared to others. The values reported for LDC (AUC = 19.37 ± 0.09 µg/mL h and VD 2.4 ± 0.24 mL) and pure drug (AUC = 8.37 ± 0.04 µg/mL h and VD = 5.24 ± 0.29 mL) indicate higher concentrations of LDC in systemic circulation, while pure 5-FU was found to be largely available in tissue rather than blood circulation. The t1/2 for LDC represents an approximate rise by ninefold, while MRT (12.10 ± 0.44 h) denotes 12-fold rise than pure 5-FU indicating the prolonged circulation of LDC. Free 5-FU concentration in the brain was maximum (5.24 ± 0.01 μg/g) after 3 h, while for the optimized formulation of LDC it was twofold greater estimated as 11.52 ± 0.32 μg/g. In conclusion, the efficiency of 5-FU to treat the brain is increased when it is formulated with LDC nanoparticles.

Stimuli-responsive In situ gelling system for nose-to-brain drug delivery

The diagnosis and treatment of neurological ailments always remain an utmost challenge for research fraternity due to the presence of BBB. The intranasal route appeared as an attractive and alternative route for brain targeting of therapeutics without the intrusion of BBB and GI exposure. This route directly and effectively delivers the therapeutics to different regions of the brain via olfactory and trigeminal nerve pathways. However, shorter drug retention time and mucociliary clearance curtail the efficiency of the intranasal route. The in situ mucoadhesive gel overthrow the limitations of direct nose-to-brain delivery by not only enhancing nasal residence time but also minimizing the mucociliary clearance and enzymatic degradation. This delivery system further improves the nasal absorption as well as bioavailability of drugs in the brain. The in situ mucoadhesive gel is a controlled and sustained release system that facilitates the absorption of various proteins, peptides and other larger lipophilic and hydrophilic moieties. Owing to multiple benefits, in situ gelling system has been widely explored to target the brain via nasal route. However, very few review works are reported which explains the application of in situ nasal gel for brain delivery of CNS acting moieties. Hence, in this piece of work, we have initially discussed the global statistics of neurological disorders reported by WHO and other reputed organizations, nasal anatomy, mechanism and challenges of nose-to-brain drug delivery. The work mainly focused on the use of different stimuli-responsive polymers, specifically thermoresponsive, pH-responsive, and ion triggered systems for the development of an effective and controlled dosage form, i.e., in situ nasal gel for brain targeting of bioactives. We have also highlighted the origin, structure, nature and phase transition behavior of the smart polymers found suitable for nasal administration, including poloxamer, chitosan, EHEC, xyloglucan, Carbopol, gellan gum and DGG along with their application in the treatment of neurological disorders. The article is aimed to gather all the information of the past 10 years related to the development and application of stimuli-responsive in situ nasal gel for brain drug delivery.

Mometasone furoate-loaded aspasomal gel for topical treatment of psoriasis: formulation, optimization, in vitro and in vivo performance

BACKGROUND

Present investigation was aimed to develop aspasomal gel of Mometasone Furoate for the treatment of Psoriasis that are biologically active and deliver drug at controlled rate and decrease dosing frequency.

METHODS

The vesicles were fabricated using film hydration method and optimized using 32 factorial Design. Prepared formulations were evaluated for percent drug loading, vesicle size, Zeta potential, polydispersity index and morphological studies. Gel was prepared using carbopol by loading optimized drug loaded asposomes and was evaluated for drug content, pH, viscosity and spreadability. The drug release study from the gel was done using dialysis membrane and goat skin. Anti- oxidant potency of the prepared aspasomal gel was determined by Ferric Reducing Assay whereas, in-vivo performance for inflammation and skin irritation was carried out using Wistar rats.

RESULTS

Optimized aspasomes demonstrated desired properties for entrapment efficiency (74.72 ± 1.8), vesicle size (282.9 ± 1.7), polydispersity index (0.2), zeta potential (-20.2 mV) with spherical shape. The results recorded for drug release from the optimized aspasomal gel exhibited sustained release (24h) compared to the marketed cream (5h). Depot formation of Mometasone furoate loaded aspasomal gel in the epidermis was confirmed by ex vivo skin penetration study by using fluorescent marker. In-vivo study revealed no any irritation and inflammation to the skin promoting drug delivery system to treat psoriasis.

CONCLUSION

In conclusion, Mometasone furoate loaded aspasomal gel releases the drug for longer duration of time and reduce dosing frequency, providing the new dimension for the treatment of psoriasis.

Development and Evaluation of in-situ Nasal Gel Formulations of Nanosized Transferosomal Sumatriptan: Design, Optimization, in vitro and in vivo Evaluation

Background

Sumatriptan succinate (SUT) is a potent drug used for relieving or ending migraine and cluster headaches. SUT bioavailability is low (15%) when it is taken orally owing to its gastric breakdown and bloodstream before reaching the target arteries.

Aim

The aim of the study was to enhance SUT bioavailability through developing an intranasal transferosomal mucoadhesive gel.

Methods

SUT-loaded nanotransferosomes were prepared by thin film hydration method and characterized for various parameters such as vesicle diameter, percent entrapment efficiency (%EE), in vitro release and ex vivo permeation studies. The in-situ gels were prepared using various ratios of poloxamer 407, poloxamer 188, and carrageenan and characterized for gelation temperature, mucoadhesive strength, and rheological properties.

Results

The prepared transferosomes exhibited percent entrapment efficiencies (%EE) of 40.41±3.02 to 77.47±2.85%, mean diameters of 97.25 to 245.01 nm, sustained drug release over 6 hours, and acceptable ex vivo permeation findings. The optimum formulae were incorporated into poloxamer 407 and poloxamer 188-based thermosensitive in-situ gel using carrageenan as a mucoadhesive polymer. Pharmacokinetic evaluation showed that the prepared in-situ gel of SUT-loaded nano-transferosomes gave enhanced bioavailability, 4.09-fold, as compared to oral drug solution.

Conclusion

Based on enhancing the bioavailability and sustaining the drug release, it can be concluded that the in-situ gel of SUT-loaded nano-transferosomes were developed as a promising non-invasive drug delivery system for treating migraine.

Local drug delivery systems in the management of periodontitis: A scientific review

Periodontitis (PD) is a microbial disease of tooth supporting tissues that results in progressive destruction of surrounding soft and hard tissues with eventual tooth mobility and exfoliation. Perioceutics, which includes the delivery of therapeutic agents via systemic and local means as an adjunct to mechanical therapy has revolutionized the arena of periodontal therapy. Selection of a right antimicrobial agent with appropriate route of drug administration is the key to successful periodontal therapy. Irrigating systems, fibers, gels, strips, films, microparticles, nanoparticles and low dose antimicrobial agents are some of the local drug delivery systems (LDDS) available in the field, which aims to deliver antimicrobial agents to sub-gingival diseased sites with minimal or no side-effects on other body sites. The present review aim to summarize the current state-of-the-art technology on LDDS in periodontal therapy ensuring the the practitioners are able to choose LDD agents which are custom made for a specific clinical condition.

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.

Neuroprotective effects of novel nanosystems simultaneously loaded with vinpocetine and piracetam after intranasal administration

AIMS

The study aim was to test the efficacy of a novel created hybrid nanosystem compared to other nanosystems in treatment of scopolamine induced memory impairment.

MAIN METHODS

The fabrication and characterization of nanoformulations (microemulsion, liposomes, ethosomes, transfersomes and transethosomes) coencapsulating two cognitive enhancers; piracetam and vinpocetine delivered intranasally, in addition to a novel nanocomposite microemulsion/vesicular nanoformulation was described.

KEY FINDINGS

Formulations delivered the drugs across sheep nasal mucosa, with cumulative percentage reaching 29.99% for vinpocetine and 57.78% for piracetam. While the solution form of the drugs was totally ineffective, the selected transethosomal, microemulsion and nanocomposite formulations reversed the scopolamine induced effect on the step through latency of passive avoidance test and the spontaneous alternation behavior in Y maze test, further confirmed by histopathlogical examination. All three nanoformulations significantly decreased the acetylcholinesterase activity and the extent of lipid peroxidation by 32-42%. The nanocomposite formulation was superior to the microemulsion and transethosomal formulations in its anti-inflammatory and antiapoptotic effects, delineated by higher extent of inhibition of COX-2 and caspase 3 expression respectively.

SIGNIFICANCE

Results support the hypothesis that the novel microemulsion/vesicular nanocomposite system is a promising neuroprotective modality for intranasal brain targeting which is worthy of exploitation in other brain diseases.

Mucosal Applications of Poloxamer 407-Based Hydrogels: An Overview

Poloxamer 407, also known by the trademark Pluronic^® F127, is a water-soluble, non-ionic triblock copolymer that is made up of a hydrophobic residue of polyoxypropylene (POP) between the two hydrophilic units of polyoxyethylene (POE). Poloxamer 407-based hydrogels exhibit an interesting reversible thermal characteristic. That is, they are liquid at room temperature, but they assume a gel form when administered at body temperature, which makes them attractive candidates as pharmaceutical drug carriers. These systems have been widely investigated in the development of mucoadhesive formulations because they do not irritate the mucosal membranes. Based on these mucoadhesive properties, a simple administration into a specific compartment should maintain the required drug concentration in situ for a prolonged period of time, decreasing the necessary dosages and side effects. Their main limitations are their modest mechanical strength and, notwithstanding their bioadhesive properties, their tendency to succumb to rapid elimination in physiological media. Various technological approaches have been investigated in the attempt to modulate these properties. This review focuses on the application of poloxamer 407-based hydrogels for mucosal drug delivery with particular attention being paid to the latest published works.

Paeonol-Loaded Ethosomes as Transdermal Delivery Carriers: Design, Preparation and Evaluation

Paeonol exhibits a wide range of pharmacological activities, such as anti-inflammatory, antidiabetic as well as pain-relieving activities. However, its intrinsic properties, such as low water solubility, poor stability and low oral bioavailability, restrict its clinical application. The current study aimed to optimize paeonol-loaded ethosomal formulation and characterize it in terms of encapsulation efficiency (EE), vesicle size (VS), zeta potential (ZP) and polydispersity index (PDI), in addition to differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) studies. Here, paeonol-loaded ethosomes were prepared by the injection method and optimized by the single-factor test and central composite design-response surface methodology. The optimized paeonol-loaded ethosomes had an EE of 84.33 ± 1.34%, VS of 120.2 ± 1.3 nm, negative charge of −16.8 ± 0.36 mV, and PDI of 0.131 ± 0.006. Ethosomes showed a spherical morphology under the transmission electron microscope (TEM). DSC, XRD and FT-IR results indicated that paeonol was successfully incorporated into the ethosomes. In-vitro transdermal absorption and skin retention of paeonol from paeonol-loaded ethosomes were 138.58 ± 9.60 µg/cm² and 52.60 ± 7.90 µg/cm², respectively. With reasonable skin tolerance, ethosomes could be a promising vehicle for transdermal delivery of paeonol.

A mucoadhesive, thermoreversible in situ nasal gel of geniposide for neurodegenerative diseases

Neurodegenerative diseases are becoming prevalent as the population ages. Geniposide could inhibit oxidative stress, reduce apoptosis, protect neuron, and has been used for therapy of the neurodegenerative diseases. The bioavailability of geniposide by nasal route is greater than that by oral administration. However, mucociliary clearance is a rate-limiting factor for nasal route administration. The objective of this study was to develop and evaluate a mucoadhesive, thermoreversible in situ nasal gel of geniposide. The poloxamers (P407, P188) and the hydroxypropyl methylcellulose were used as thermoreversible and mucoadhesive polymers, respectively. Borneol was used as a permeation enhancer. The hydrogel was prepared with the cold method and optimized by the response surface methodology-central composite design. Gelation temperature, pH, clarity, gel strength, mucoadhesive strength, in vitro and ex vivo release kinetics of formulations were evaluated. The optimized amounts of poloxamer407 (P407), poloxamer188 (P188) and hydroxypropyl methylcellulose were determined to be 19.4-20.5%, 1.1-4.0% and 0.3-0.6% respectively. The second-order polynomial equation in terms of actual factors indicated a satisfactory correlation between the independent variables and the response (R2 = 0.9760). An ANOVA of the empirical second-order polynomial model indicated the model was significant (P<0.01). P407, P188, P407×P188, P4072 and P1882 were significant model terms. The effects of P407 on gelation temperature were greater than those of other independent variables. The pH values of all the formulations were found to be within 6.3-6.5 which was in the nasal physiological pH range 4.5-6.5. The drug content, gel strength, mucoadhesive strength of the optimized formulations were 97-101%, 25-50 sec and 4000-6000 dyn/cm2 respectively. The in vitro release kinetics of cumulative release of geniposide was fitted to the zero-order model. The ex vivo cumulative release kinetics of geniposide was fitted to the Weibull model. This study concludes that the release of geniposide is controlled by gel corrosion, and that the permeation of geniposide is time-dependent. The more residence time, mucoadhesive, thermoreversible in situ nasal gel of geniposide for neurodegenerative diseases is of compliance and potential application.

Formulation, physicochemical characterization and in vitro evaluation of human insulin-loaded microspheres as potential oral carrier

Abstract

The objective of the present investigation was to formulate and characterize the human insulin entrapped Eudragit S100 microspheres containing protease inhibitors and to develop an optimized formulation with desirable features. A w/o/w multiple emulsion solvent evaporation technique was employed to produce microspheres of human insulin using Eudragit S-100 as coating material and polyvinyl alcohol as a stabilizer. The resultant microspheres were evaluated for drug-excipient compatibility, encapsulation efficiency, particle size, surface morphology, micromeritic properties, enteric nature, and in vitro drug release studies. Micromeritic properties indicated good flow properties and compressibility. In present investigation formulation F6 with drug/polymer ratio (1:100) was found to be optimal in terms of evaluated parameters where it showed a significantly higher percentage of encapsulation efficiency (76.84%) with minimal drug release (3.25%) in an acidic environment. The optimized formulation (F6) also possessed good spherical shape and particle size (57.42 µm) required to achieve the desired in vitro drug release profile at pH 7.4. The results confirmed that human insulin-loaded Eudragit S-100 microspheres containing protease inhibitor possessed good encapsulation efficiency, pH dependant controlled release carrying encapsulated insulin to its optimum site of absorption. This ultimately resulted in enhanced insulin absorption and biological response.

Graphical Abstract

Floating Hydrogel with Self-Generating Micro-Bubbles for Intravesical Instillation

Intravesical instillation is the main therapy for bladder cancer and interstitial cystitis. However, most drug solutions are eliminated from bladder after the first voiding of urine. To solve this problem, we proposed a floating hydrogel with self-generating micro-bubbles as a new delivery system. It floated in urine, avoiding the urinary obstruction and bladder irritation that ordinary hydrogels caused. In this study, we abandoned traditional gas-producing method like chemical decomposition of NaHCO₃, and used the foamability of Poloxamer 407 (P407) instead. Through simple shaking (just like shaking SonoVue for contrast-enhanced ultrasound in clinical), the P407 solution will “lock” many micro-bubbles and float in urine as quickly and steadily as other gas producing materials. In vivo release experiments showed that drug was released continually from hydrogel for 10 h during the erosion process. Thus, the residence time of drug in bladder was prolonged and drug efficacy was improved. In vivo efficacy study using rabbit acute bladder injury model showed that prolonged drug residence time in bladder increased the efficiency of heparin in the protection of bladder mucosal permeability. Therefore, our floating hydrogel system with self-generating micro-bubbles was single-component, simply prepared and efficacy enhancing, successfully exempting users from worries on safety and clinical efficiency from bench to bedside.