Intranasal delivery of ciprofloxacin to rats: A topical approach using a thermoreversible in situ gel

Holistic Study Design Following Quality by Design Approach for Fabrication of Hybrid Polymeric Nanoparticulate Based Dry Powders as Carriers for Ciprofloxacin

Resistance to antibiotics such as Ciprofloxacin (CIP) is becoming a critical issue and needs to be addressed globally. CIP is widely used because of manifold uses; however, the long-term therapy poses serious health risks including FDA black box warnings such as tendinitis and peripheral neuropathy. Therefore, nanotechnology-based products can be an effective measure to improve therapeutic outcomes by maintaining the dose at the target site while reducing the dose-dependent toxicity. Biodegradable and biocompatible polymers, Chitosan (CS) and Hyaluronic acid (HA) were used in this work due to their diverse biological characteristics. A simple yet economical ionic gelation method was employed to synthesize nanoparticles with a plexus-like network; nanoplexes, followed by spray-drying to obtain the dry powders to improve stability. Quality by Design (QbD) approach was utilized during the study for robustness and standardization followed by Design of Experiment (DoE) for optimization in a holistic way. The mean particle size of the optimized powder sample was found to be 301.1 nm with a percentage encapsulation efficiency (% EE) of 78.8%. In-vitro dissolution studies corroborated the controlled release of CIP over 48 h. Also, mathematical kinetic modeling was applied to obtain thorough insight into the mechanism of drug release. Moreover, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were presented to be lower in the case of prepared dry powder as compared to CIP, stating that nanotechnology can improve antimicrobial activity.

Essential considerations towards development of effective nasal antibiotic formulation: features, strategies, and future directions

INTRODUCTION

Intranasal antibiotic products are gaining popularity as a promising method of administering antibiotics, which provide numerous benefits, e.g. enhancing drug bioavailability, reducing adverse effects, and potentially minimizing resistance threats. However, some issues related to the antibiotic substances and nasal route challenges must be addressed to prepare effective formulations.

AREAS COVERED

This review focuses on the valuable points of nasal delivery as an alternative route for administering antibiotics, coupled with the challenges in the nasal cavity that might affect the formulations. Moreover, this review also highlights the application of nasal delivery to introduce antibiotics for local therapy, brain targeting, and systemic effects that have been conducted. In addition, this viewpoint provides strategies to maintain antibiotic stability and several crucial aspects to be considered for enabling effective nasal formulation.

EXPERT OPINION

In-depth knowledge and understanding regarding various key considerations with respect to the antibiotic substances and nasal route delivery requirement in preparing effective nasal antibiotic formulation would greatly improve the development of nasally administered antibiotic products, enabling better therapeutic outcomes of antibiotic treatment and establishing appropriate use of antibiotics, which in turn might reduce the chance of antibiotic resistance and enhance patient comfort.

Suppressive Effects of Neuromedin U Receptor 2-Selective Peptide Agonists on Appetite and Prolactin Secretion in Mice

Neuromedin U receptor 2 (NMUR2), which is expressed in the central nervous system (CNS) including the hypothalamus, has been noted as a therapeutic target against obesity. We previously reported that intranasal administration of CPN-219, a NMUR2-selective hexapeptide agonist, suppresses body weight gain in mice; however, there is no detailed information regarding its CNS effects. Recently, in addition to appetite suppression, stress responses and regulation of prolactin (PRL) secretion have also attracted attention. NMUR2 expressed in the hypothalamic tuberoinfundibular dopaminergic neurons has emerged as an alternative target for treating hyperprolactinemia. Here, CPN-219 decreased food intake up to 24 h after administration at a dose of 200 nmol, resulting in body weight gain suppression, although grooming and anxiety-like behaviors were transiently induced. Interestingly, the restraint stress-induced increase in plasma PRL levels was significantly suppressed at a lower dose of 20 nmol, indicating the potential for drug development as an anti-PRL agent of NMUR2-selective agonists.

Formulation development and evaluation of nasal in situ gel of promethazine hydrochloride

OBJECTIVE

The present work aims to develop mucoadhesive thermosensitive nasal in situ gel for Promethazine hydrochloride using quality by design (QbD) approach. It can reduce nasal mucociliary clearance (MCC) and increase residence of the drug on nasal mucosa. This might increase drug absorption to improve bioavailability of the drug as compared to oral dosage form.

SIGNIFICANCE

Promethazine hydrochloride is an antiemetic drug administered by oral, parenteral and rectal routes. These routes have poor patient compliance or low bioavailability. Nasal route is a better alternative as it has large surface area, high drug absorption rate and no first pass effect. Its only limitation is short drug retention time due to MCC. By formulating a mucoadhesive in situ gel, the MCC can be reduced, and drug absorption will be prolonged. Thus, improving bioavailability.

METHOD

In-situ gel was prepared by cold method having material attributes as concentration of Poloxamer 407 (X1) as gelling agent and hydroxypropyl methyl cellulose K4M (X2) as mucoadhesive agent. Critical Quality Attributes (CQA) were gelation temperature, mucoadhesive force and ex-vivo diffusion. Central composite design (CCD) was adopted for optimization.

RESULT

Optimized formulation satisfied all the CQA significant for nasal administration. Moreover, the formulation was found to be stable in accelerated stability studies for 3 months.

CONCLUSION

It can be concluded that since the drug can easily permeate through nasal mucosa and can gain access directly in the brain without undergoing first pass metabolism along with increased residence due to mucoadhesion, mucoadhesive in situ gel has potential to increase drug bioavailability.

Main Aspects of Pharmaceutical Development of In situ Immunobiological Drugs for Intranasal Administration

INTRODUCTION

The review presents the latest developments in the area of intranasal in situ delivery systems of immunobiological drugs (IBDs). Interest in intranasal administration for IBDs has increased significantly due to the COVID-19 pandemic. However, not only intranasal delivery of vaccines is developing, but also bacteriophages, interferons, etc. In situ systems that make a selective phase transition can be a modern solution to intranasal delivery problems caused by mucociliary clearance. In addition, smart-polymers used as the main excipients in in situ systems can be used as specific adjuvants.

METHODS

A scientific search was conducted on the PubMed database of medical publications for the period from 2000 to 2022, using the keywords "intranasal in situ vaccine"; "intranasal in situ immunization". There were analyzed in detail more than 70 scientific studies on intranasal in situ delivery of IBDs.

RESULTS AND CONCLUSIONS

Despite the large number of new studies, the potential of possibilities of intranasal in situ systems is not being realized. Based on the results of the literature review an algorithm was created for the development of in situ systems for intranasal delivery of IBDs. Such algorithms and the methods of study design organization described in the review will help to facilitate the R&D process and bring the drug to commercial market, which will help to improve the quality of medical care.

Development of Thermoresponsive-Gel-Matrix-Embedded Amoxicillin Trihydrate-Loaded Bovine Serum Albumin Nanoparticles for Local Intranasal Therapy

A high dose of amoxicillin is recommended as the first-line therapy for acute bacterial rhinosinusitis (ABR). However, oral administration of amoxicillin is connected to many adverse reactions coupled with moderate bioavailability (~60%). Therefore, this study aimed to develop a topical nasal preparation of amoxicillin, employing a thermoresponsive nanogel system to increase nasal residence time and prolong drug release. Rheological investigations revealed that formulations containing 21−23% w/w Poloxamer 407 (P407) were in accordance with the requirement of nasal administration (gelling temperature ~35 °C). The average hydrodynamic diameter (<200 nm), pH (6.7−6.9), and hypertonic osmolality (611−663 mOsmol/L) of the in situ gelling nasal nanogel appeared as suitable characteristics for local rhinosinusitis treatment. Moreover, taking into account the mucoadhesive strength and drug release studies, the 21% w/w P407 could be considered as an optimized concentration for effective nasal delivery. Antibacterial activity studies showed that the ability of amoxicillin-loaded in situ gelling nasal nanogel to inhibit bacterial growth (five common ABR pathogens) preserved its effectiveness in comparison to 1 mg/mL amoxicillin aqueous solution as a positive control. Altogether, the developed amoxicillin-loaded in situ gelling thermoresponsive nasal nanogel can be a potential candidate for local antibiotic therapy in the nasal cavity.

Formulation and In Vitro Characterization of a Vacuum-Dried Drug–Polymer Thin Film for Intranasal Application

Intranasal drug applications show significant therapeutic potential for diverse pharmaceutical modalities. Because the formulation applied to the nasal cavity is discharged to the pharyngeal side by mucociliary clearance, the formulation should be dissolved effectively in a limited amount of mucus within its retention time in the nasal cavity. In this study, to develop novel formulations with improved dissolution behavior and compatibility with the intranasal environment, a thin-film formulation including drug and polymer was prepared using a vacuum-drying method. The poorly water-soluble drugs ketoprofen, flurbiprofen, ibuprofen, and loxoprofen were dissolved in a solvent comprising water and methanol, and evaporated to obtain a thin film. Physical analyses using differential scanning calorimetry (DSC), powder X-ray diffraction analysis (PXRD), and scanning electron microscopy SEM revealed that the formulations were amorphized in the film. The dissolution behavior of the drugs was investigated using an in vitro evaluation system that mimicked the intranasal physiological environment. The amorphization of drugs formulated with polymers into thin films using the vacuum-drying method improved the dissolution rate in artificial nasal fluid. Therefore, the thin film developed in this study can be safely and effectively used for intranasal drug application.

Mucoadhesive, Thermoreversible Hydrogel, Containing Tetracaine-Loaded Nanostructured Lipid Carriers for Topical, Intranasal Needle-Free Anesthesia

Recent advances have been reported for needle-free local anesthesia in maxillary teeth by administering a nasal spray of tetracaine (TTC) and oxymetazoline, without causing pain, fear, and stress. This work aimed to assess whether a TTC-loaded hybrid system could reduce cytotoxicity, promote sustained permeation, and increase the anesthetic efficacy of TTC for safe, effective, painless, and prolonged analgesia of the maxillary teeth in dental procedures. The hybrid system based on TTC (4%) encapsulated in nanostructured lipid carriers (NLC) and incorporated into a thermoreversible hydrogel of poloxamer 407 (TTCNLC-HG4%) displayed desirable rheological, mechanical, and mucoadhesive properties for topical application in the nasal cavity. Compared to control formulations, the use of TTCNLC-HG4% slowed in vitro permeation of the anesthetic across the nasal mucosa, maintained cytotoxicity against neuroblastoma cells, and provided a three-fold increase in analgesia duration, as observed using the tail-flick test in mice. The results obtained here open up perspectives for future clinical evaluation of the thermoreversible hybrid hydrogel, which contains TTC-loaded NLC, with the aim of creating an effective, topical, intranasal, needle-free anesthesia for use in dentistry.

Promising Polymeric Drug Carriers for Local Delivery: The Case of in situ Gels

BACKGROUND

At present, the controlled local drug delivery is a very promising approach compared to systemic administration, since it mostly targets the affected tissue. In fact, various drug carriers for local delivery have been prepared with improved therapeutic efficacy.

OBJECTIVE

in situ polymer gels are drug delivery systems that not only present liquid characteristics before their administration in body, but once they are administered, form gels due to gelation. Their gelation mechanism is due to factors such as pH alteration, temperature change, ion activation or ultraviolet irradiation. in situ gels offer various advantages compared to conventional formulations due to their ability to release drugs in a sustainable and controllable manner. Most importantly, in situ gels can be used in local drug delivery applications for various diseases.

METHODS

This review includes the basic knowledge and theory of in situ gels as well as their various applications according to their administration route.

RESULTS

Various natural, semisynthetic, and synthetic polymers can produce in situ polymeric gels. For example, natural polysaccharides such as alginic acid, chitosan, gellan gum, carrageenan etc. have been utilized as in situ gels for topical delivery. Besides the polysaccharides, poloxamers, poly(Nisopropylacrylamide), poly(ethyleneoxide)/ (lactic-co-glycolic acid), and thermosensitive liposome systems can be applied as in situ gels. In most cases, in situ polymeric gels could be applied via various administration routes such as oral, vaginal, ocular, intranasal and injectable.

CONCLUSION

To conclude, it can be revealed that in situ gels could be a promising alternative carrier for both chronic and immediate diseases.

Plant-derived exosome-like nanoparticles and their therapeutic activities

Nanotechnologies have been successfully applied to the treatment of various diseases. Plant-derived exosome-like nanoparticles (PENs) are expected to become effective therapeutic modalities for treating disease or in drug-delivery. PENs are minimally cytotoxic to healthy tissues, with which they show excellent biocompatibility, and are biased towards tumors by targeting specific tissues through special endocytosis mechanisms. Thus, the use of these PENs may expand the scope of drug therapies while reducing the off-target effects. In this review, we summarize the fundamental features and bioactivities of PENs extracted from the grape, grapefruit, ginger, lemon, and broccoli and discuss the applications of these particles as therapeutics and nanocarriers.

Formulation optimization of smart thermosetting lamotrigine loaded hydrogels using response surface methodology, box benhken design and artificial neural networks

The aim of this research was to develop lamotrigine containing thermosetting hydrogel for intranasal administration to manage and treat generalized epilepsy. Thermosetting hydrogels were prepared using different ratios of poloxamer 407 (L127), poloxamer 188 (L68) and Carbopol^® 974 P NF (C974) using the cold production process. The in situ thermosetting hydrogel was optimized using Box Behken design. Co-solvency approach was used to increase the solubility of lamotrigine by dissolving it in propylene glycol and polyethylene glycol 400 (0.2: 0.8) and the resultant solution was incorporated in the hydrogel to manufacture an LTG hydrogel. The presence of a higher amount of L127 resulted in higher viscosity at 22 °C and 34 °C and decreased the overall release of LTG. An increase in the amount of C974 resulted in a decrease in the pH of the hydrogel. The results show that formulations F10, F12, F13, F14, F15, F16 and F17 exhibited acceptable thermosetting behavior, pH and released adequate Lamotrigine above the minimum effective concentration to treat generalized epilepsy. The optimized formulation exhibited acceptable thermosetting behavior, pH and lamotrigine release but formed a stiff gel at 22 °C. The average LTG content of the optimized hydrogel was 5.00 ± 0.0225 mg/ml with % recovery of 99.17%. The amount of LTG released at 12 h from the optimized hydrogel was 3.21 ± 0.0155 mg and will be therapeutically effective in the brain after absorption via the olfactory region in the nasal cavity.

Transnasal Delivery of the Peptide Agonist Specific to Neuromedin-U Receptor 2 to the Brain for the Treatment of Obesity

Obesity and metabolic syndrome are threats to the health of large population worldwide as they are associated with high mortality, mainly linked to cardiovascular diseases. Recently, CPN-116 (CPN), which is an agonist peptide specific to neuromedin-U receptor 2 (NMUR2) that is expressed predominantly in the brain, has been developed as a new therapeutic candidate for the treatment of obesity and metabolic syndrome. However, treatment with CPN poses a challenge due to the limited delivery of CPN to the brain. Recent studies have clarified that the direct anatomical connection of the nasal cavity with brain allows delivery of several drugs to the brain. In this study, we confirm the nasal cavity as a promising CPN delivery route to the brain for the treatment of obesity and metabolic syndrome. According to the pharmacokinetic study, the clearance of CPN from the blood was very rapid with a half-life of 3 min. In vitro study on its stability in the serum and cerebrospinal fluid (CSF) indicates that CPN was more stable in the CSF than in the blood. The concentration of CPN in the brain was higher after nasal administration, despite its lower concentrations in the plasma than that after intravenous administration. The study on its pharmacological potency suggests the effective suppression of increased body weight in mice in a dose-dependent manner due to the direct activation of NMUR2 by CPN. This results from the higher concentration of corticosterone in blood after nasal administration of CPN as compared to nasal application of saline. In conclusion, the above findings indicate that the nasal cavity is a promising CPN delivery route to the brain to treat obesity and metabolic syndrome.

Updates on thermosensitive hydrogel for nasal, ocular and cutaneous delivery

Thermosensitive hydrogels are in situ gelling systems composed of hydrophilic homopolymers or block copolymers which remain as solutions at room temperature and form gels after administration into the body. Its application in advanced drug delivery has gained significant attention in recent years. The tunable characteristics of thermosensitive hydrogels make them versatile and capable of incorporating both hydrophilic and lipophilic compounds and macromolecules. The drug molecules can be included as free molecules or preformulated into nano- or micro-particles or liposomes. Although there were several reviews on the materials of thermosensitive hydrogels, the compatibility between the drug and thermosensitive material as well as its in vitro release mechanisms and in vivo performance have barely been investigated. The current review is proposed aiming to not only provide an update on the recent development in thermosensitive hydrogel formulations for nasal, ocular and cutaneous deliveries, but also identify the relationship between the drug characteristics and the loading strategies, and their impacts on the release mechanisms and the in vivo performance. Our current update for the first time highlights the essential features for successful development of in situ thermosensitive hydrogels to facilitate nasal, ocular or cutaneous drug deliveries.

Electrospinning of Cyclodextrin Functional Nanofibers for Drug Delivery Applications

Electrospun nanofibers have sparked tremendous attention in drug delivery since they can offer high specific surface area, tailored release of drugs, controlled surface chemistry for preferred protein adsorption, and tunable porosity. Several functional motifs were incorporated into electrospun nanofibers to greatly expand their drug loading capacity or to provide the sustained release of the embedded drug molecules. In this regard, cyclodextrins (CyD) are considered as ideal drug carrier molecules as they are natural, edible, and biocompatible compounds with a truncated cone-shape with a relatively hydrophobic cavity interior for complexation with hydrophobic drugs and a hydrophilic exterior to increase the water-solubility of drugs. Further, the formation of CyD-drug inclusion complexes can protect drug molecules from physiological degradation, or elimination and thus increases the stability and bioavailability of drugs, of which the release takes place with time, accompanied by fiber degradation. In this review, we summarize studies related to CyD-functional electrospun nanofibers for drug delivery applications. The review begins with an introductory description of electrospinning; the structure, properties, and toxicology of CyD; and CyD-drug complexation. Thereafter, the release of various drug molecules from CyD-functional electrospun nanofibers is provided in subsequent sections. The review concludes with a summary and outlook on material strategies.

Overview of Drug Delivery Methods in Exotics, Including Their Anatomic and Physiologic Considerations

Drug delivery to exotic animals may be extrapolated from domestic animals, but some physiologic and anatomic differences complicate treatment administration. Knowing these differences enables one to choose optimal routes for drug delivery. This review provides practitioners with a detailed review of the currently reported methods used for drug delivery of various medications in the most common exotic animal species. Exotic animal peculiarities that are relevant for drug administration are discussed in the text and outlined in tables and boxes to help the reader easily find targeted information.

Aliphatic Polyester Nanofibers Functionalized with Cyclodextrins and Cyclodextrin-Guest Inclusion Complexes

The fabrication of nanofibers by electrospinning has gained popularity in the past two decades; however, only in this decade, have polymeric nanofibers been functionalized using cyclodextrins (CDs) or their inclusion complexes (ICs). By combining electrospinning of polymers with free CDs, nanofibers can be fabricated that are capable of capturing small molecules, such as wound odors or environmental toxins in water and air. Likewise, combining polymers with cyclodextrin-inclusion complexes (CD-ICs), has shown promise in enhancing or controlling the delivery of small molecule guests, by minor tweaking in the technique utilized in fabricating these nanofibers, for example, by forming core⁻shell or multilayered structures and conventional electrospinning, for controlled and rapid delivery, respectively. In addition to small molecule delivery, the thermomechanical properties of the polymers can be significantly improved, as our group has shown recently, by adding non-stoichiometric inclusion complexes to the polymeric nanofibers. We recently reported and thoroughly characterized the fabrication of polypseudorotaxane (PpR) nanofibers without a polymeric carrier. These PpR nanofibers show unusual rheological and thermomechanical properties, even when the coverage of those polymer chains is relatively sparse (~3%). A key advantage of these PpR nanofibers is the presence of relatively stable hydroxyl groups on the outer surface of the nanofibers, which can subsequently be taken advantage of for bioconjugation, making them suitable for biomedical applications. Although the number of studies in this area is limited, initial results suggest significant potential for bone tissue engineering, and with additional bioconjugation in other areas of tissue engineering. In addition, the behaviors and uses of aliphatic polyester nanofibers functionalized with CDs and CD-ICs are briefly described and summarized. Based on these observations, we attempt to draw conclusions for each of these combinations, and the relationships that exist between their presence and the functional behaviors of their nanofibers.

Statistical Design of Experiment (DoE) based development and optimization of DB213 in situ thermosensitive gel for intranasal delivery

DB213 is an HIV-1 replication inhibitor targeting the Central Nervous System for the treatment of HIV-associated neurocognitive disorders. Current study aims to develop an in situ thermosensitive gelling system for intranasal delivery of DB213 facilitated by Statistical Design of Experiment (DoE) to conduct a more efficient experimentation by extracting the maximum amount of information from limited experiments. In our current study, information was extracted from twenty-five experimental designs from MODDE^® Software and a mathematical model was successfully developed to predict formulations to achieve desired performance as well as to analyze relationships between the amount of Pluronic F-127, Pluronic F-68, Chitosan, DB213 and the performances of in situ thermosensitive gels. Based on DoE, in situ thermosensitive gels of 1% DB213 (F1) and 5% DB213 (F2) were developed for further in vivo bioavailability and brain uptake evaluations in Sprague-Dawley rats and C57BL/6 mice, respectively. In comparison to DB213 water solution, intranasal administrations of F1 at 1 mg/kg in rats and F2 at 25 mg/kg in mice demonstrated relative bioavailabilities of 145% and 165% with significant increase in brain uptake.

Non-invasive strategies for targeting the posterior segment of eye

The safe and effective treatment of eye diseases has been remained a global myth. Several advancements have been done and various drug delivery and treatment techniques have been suggested. The Posterior segment disorders are the leading cause of visual impairments and blindness. Targeting the therapeutic agents to the anterior and posterior segments of the eye has attracted extensive attention from the scientific community. Significant key factors in the success of ocular therapy are the development of safe, effective, economic and non-invasive novel drug delivery systems. These specialized non-invasive ocular drug delivery systems revolutionized the drug delivery strategies by overcoming the limitations, provided targeted delivery to the ocular tissues by avoiding larger doses, and reducing the toxicity encountered by the conventional approaches. These non-invasive systems are fabricated by ingredients encompassing biodegradability, biocompatibility, mucoadhesion, solubility and permeability enhancement and stimuli responsiveness. The variety of routes are utilized to provide minimally invasive drug delivery to the patients without any discomfort and pain. This review is focused on the brief introduction, types, significance, preparation techniques, components and mechanism of drug release of non-invasive systems, including in situ gelling systems, microspheres, iontophoresis, nanoparticles, nanosuspensions and specialized novel emulsions.