In Vitro and Ex Vivo Evaluation of Nepafenac-Based Cyclodextrin Microparticles for Treatment of Eye Inflammation

Physical and mechanical properties of ocular thin films: a systematic review and meta-analysis

The ocular thin film presents a potential solution for addressing challenges to ocular drug delivery. In this review, we summarise the findings of a comprehensive review analysing 336 formulations from 68 studies. We investigated the physical and mechanical properties of ocular thin films, categorised into natural polymer-based, synthetic polymer-based, and combined polymer films. The results showed that the type of polymers used impacted mucoadhesion force, moisture absorption:moisture loss ratio, pH, swelling index, and elongation percentage. Significant relationships were found between these properties within each subgroup. The results also highlighted the influence of plasticisers on elongation percentage, mucoadhesion force, swelling index, and moisture absorption:moisture loss ratio. These findings have implications for designing and optimising ocular drug formulations and selecting appropriate plasticisers to achieve formulations with the desired properties.

A Postbiotic Formulation of Lactiplantibacillus plantarum CRL 759 Attenuates Endotoxin Induced Uveitis

PURPOSE

To evaluate the anti-inflammatory activity of a cell-free supernatant from Lactiplantibacillus plantarum CRL 759, in phosphate buffer modified according to Sorensen called POF-759.

METHODS

The activity of POF-759 administered by means of eye drops was evaluated on animals subcutaneously injected with the lipopolysaccharide animals in which uveitis was induced by a subcutaneous injection of lipopolysaccharide (EIU). Clinical signs of ocular inflammation, cytokines and proteins were examined in the aqueous humor. Additionally, cellular infiltration was evaluated by histopathological analysis.

RESULTS

The new postbiotic administered locally decreases signs of ocular damage, the number of infiltrating cells in the anterior and posterior chambers, the proinflammatory mediators and the proteins in the aqueous humor on mice with EIU.

CONCLUSIONS

Our results provide an impetus to relieve ocular inflammation and to identify and develop preventive and therapeutic approaches, to avoid deterioration and to maintain healthy eyes on inflammatory processes.

Dexamethasone phosphate and penetratin co-eluting contact lenses: a strategy to enhance ocular drug permeability

Contact lenses (CLs) have been suggested as drug delivery platforms capable of increasing the drug residence time on the cornea and therefore its bioavailability. However, when targeting the posterior segment of the eye, the drug released from CLs still encounters the barrier effect of the ocular tissues, which considerably reduces the efficacy of administration. This work aims at the development of CLs able to simultaneously deliver an anti-inflammatory drug (dexamethasone sodium phosphate) and a cell-penetrating peptide (penetratin), the latter acting as a drug carrier across the tissues. Hydroxyethyl methacrylate (HEMA)-based hydrogels were functionalized with acrylic acid (AAc) and/or aminopropyl methacrylamide (APMA) to serve as CL materials with increased affinity for the drug and peptide. APMA-functionalized hydrogels sustained the dual release for 8 h, which is compatible with the wearing time of daily CLs. Hydrogels demonstrated suitable light transmittance, swelling capacity and in vitro biocompatibility. The anti-inflammatory activity of the drug was not compromised by the presence of the peptide nor by sterilization. The ocular distribution of the drug after 6 h of CL wearing was evaluated in vivo in rabbits and revealed that the amount of drug in the cornea and aqueous humor significantly increased when the drug was co-delivered with penetratin.

Application of Starch, Cellulose, and Their Derivatives in the Development of Microparticle Drug-Delivery Systems

Micro- and nanotechnologies have been intensively studied in recent years as novel platforms for targeting and controlling the delivery of various pharmaceutical substances. Microparticulate drug delivery systems for oral, parenteral, or topical administration are multiple unit formulations, considered as powerful therapeutic tools for the treatment of various diseases, providing sustained drug release, enhanced drug stability, and precise dosing and directing the active substance to specific sites in the organism. The properties of these pharmaceutical formulations are highly dependent on the characteristics of the polymers used as drug carriers for their preparation. Starch and cellulose are among the most preferred biomaterials for biomedical applications due to their biocompatibility, biodegradability, and lack of toxicity. These polysaccharides and their derivatives, like dextrins (maltodextrin, cyclodextrins), ethylcellulose, methylcellulose, hydroxypropyl methylcellulose, carboxy methylcellulose, etc., have been widely used in pharmaceutical technology as excipients for the preparation of solid, semi-solid, and liquid dosage forms. Due to their accessibility and relatively easy particle-forming properties, starch and cellulose are promising materials for designing drug-loaded microparticles for various therapeutic applications. This study aims to summarize some of the basic characteristics of starch and cellulose derivatives related to their potential utilization as microparticulate drug carriers in the pharmaceutical field.

Cyclodextrin-enabled nepafenac eye drops with improved absorption open a new therapeutic window

Nepafenac is a highly effective NSAID used for treating postoperative ocular inflammation and pain after cataract surgery and its advantage over conventional topical NSAIDs has been proved many times. However, Nevanac® is a suspension eye drop, which clearly lacks patient compliance causing irritation, blurred vision, foreign body sensation along with problematic dosage due to its sticky, inhomogeneous consistence. In this study, nepafenac containing eye drops were prepared using hydroxypropyl-β-cyclodextrin to ensure complete dissolution of nepafenac, sodium hyaluronate to provide mucoadhesion and adequate viscosity and a preservative-free officinal formula, Oculogutta Carbomerae containing carbomer (just like Nevanac®), therefore providing a similar base for the new formulations. According to an experimental design, 11 formulations were tested in vitro including two reference formulations by measuring their viscosity, mucoadhesion, drug release and corneal permeability. Finally, two formulations were found promising and investigated further on porcine eyes ex vivo and corneal distribution of nepafenac was determined by RAMAN mapping. The results showed that one formulation possessed better bioavailability ex vivo than Nevanac® 0.1 % suspension, while the other formulation containing only 60 % of the original dose were ex vivo equivalent with Nevanac® opening the way to nepafenac-containing eye drops with better patient compliance in the future.

Biopolymers in Mucoadhesive Eye Drops for Treatment of Dry Eye and Allergic Conditions: Application and Perspectives

Dry eye syndrome and allergic conjunctivitis are the most common inflammatory disorders of the eye surface. Although eye drops are the most usual prescribed dosage form, they are characterized by low ocular availability due to numerous barrier mechanisms of the eye. The use of biopolymers in liquid ophthalmic preparations has numerous advantages, such as increasing the viscosity of the tear film, exhibiting bioadhesive properties, and resisting the drainage system, leading to prolonged retention of the preparation at the site of application, and improvement of the therapeutic effect. Some mucoadhesive polymers are multifunctional excipients, so they act by different mechanisms on increasing the permeability of the cornea. Additionally, many hydrophilic biopolymers can also represent the active substances in artificial tear preparations, due to their lubrication and moisturizing effect. With the modification of conventional ophthalmic preparations, there is a need for development of new methods for their characterization. Numerous methods for the assessment of mucoadhesiveness have been suggested by the literature. This review gives an overview related to the development of mucoadhesive liquid ophthalmic formulations for the treatment of dry eye and allergic conditions.

Development of an ophthalmic formulation with a postbiotic of Lactiplantibacillus plantarum CRL 759

The term postbiotics has acquired great interest in recent years. Numerous studies have shown a potential beneficial effect of its use in many inflammatory pathologies. However, it has not been much explored in ocular inflammatory diseases. The aims of this study were to develop and characterise an ophthalmic formulation with a postbiotic of Lactiplantibacillus plantarum CRL 759, and to evaluate its anti-inflammatory actions on murine macrophage stimulated with lipopolysaccharides (LPS) in vitro. First, we evaluated the ability of L. plantarum CRL 759 to generate a supernatant with anti-inflammatory property using different buffers. Then, we studied the stability at different temperatures and storage times of the generated postbiotic. In vitro assays showed that incubation of L. plantarum CRL 759 in modified phosphate buffer according to Sorensen (called POF-759), generated a supernatant that significantly reduced the production of interleukin-6, tumour necrosis factor-α, and nitric oxide by RAW 264.7 cells stimulated with LPS. Furthermore, POF-759 maintained its anti-inflammatory activity at room temperature, 4 and -20 °C, up to 30 days of storage. From the studies reported here, a postbiotic product with anti-inflammatory properties and optimal characteristics for the formulation of eye drops was obtained.

Mucoadhesive brinzolamide-loaded nanofibers for alternative glaucoma treatment

Despite the advances in the field of pharmaceutical materials and technology, topical administration remains a method of choice for the treatment of eye diseases such as glaucoma, with eye drops being a leading dosage form. Their main disadvantage is a very short drug residence time and thus poor drug bioavailability, leading to the necessity of continuous repeated dosing. Mucoadhesive electrospun nanofibers are promising candidates for overcoming these challenges, while still benefiting from topical ocular administration. As an alternative for eye drops, a nanofibrous drug delivery system (DDS) for the delivery of brinzolamide (BRZ), based on β-cyclodextrin (β-CD), hydroxypropyl cellulose (HPC) and polycaprolactone (PCL), was designed. The results showed β-CD/BRZ guest-host interactions, successful drug incorporation into the nanofibers, and the possibility of more accurate dosing in comparison with the control eye drops. Drug permeation through sheep corneas was almost linear in time, achieving therapeutic concentrations in the receptor medium, and mucoadhesion to sheep eye mucosa was relatively high in case of formulations with high HPC content. All formulations were biocompatible, their mechanical properties were sufficient to handle them without caution and UV irradiation was suitable to reduce bioburden of the fibers matrix, yet no antibacterial properties of BRZ were observed.

Long-acting formulation strategies for protein and peptide delivery in the treatment of PSED

The invigoration of protein and peptides in serious eye disease includes age-related macular degeneration, choroidal neovascularization, retinal neovascularization, and diabetic retinopathy. The transportation of macromolecules like aptamers, recombinant proteins, and monoclonal antibodies to the posterior segment of the eye is challenging due to their high molecular weight, rapid degradation, and low solubility. Moreover, it requires frequent administration for prolonged therapy. The long-acting novel formulation strategies are helpful to overcome these issues and provide superior therapy. It avoids frequent administration, improves stability, high retention time, and avoids burst release. This review briefly enlightens posterior segments of eye diseases with their diagnosis techniques and treatments. This article mainly focuses on recent advanced approaches like intravitreal implants and injectables, electrospun injectables, 3D printed drug-loaded implants, nanostructure thin-film polymer devices encapsulated cell technology-based intravitreal implants, injectable and depots, microneedles, PDS with ranibizumab, polymer nanoparticles, inorganic nanoparticles, hydrogels and microparticles for delivering macromolecules in the eye for intended therapy. Furthermore, novel techniques like aptamer, small Interference RNA, and stem cell therapy were also discussed. It is predicted that these systems will make revolutionary changes in treating posterior segment eye diseases in future.

Chitosan/sulfobutylether-β-cyclodextrin based nanoparticles coated with thiolated hyaluronic acid for indomethacin ophthalmic delivery

Indomethacin (IND) is topically administered for the treatment of the anterior segment diseases such as conjunctivitis, uveitis, and inflammation prevention for post-cataract surgery, as well as posterior segment diseases as macular edema. Currently IND is available as 0.1% w/v hydroxypropyl-β-cyclodextrin-based eye drop formulation and its bioavailability is limited by several drawbacks such as the nasolacrimal duct draining, the reflex blinking and the low volume of the conjunctival sac. In this study, chitosan (CS)/sulfobutylether-β-cyclodextrin (SBE-β-CD) based nanoparticles (NPs) with a mean diameter of 340 (±7) nm, a ζ-potential value of +18.3 (±0.5) mV and coated with thiolated low molecular weight hyaluronic acid were formulated to improve both the solubility and the residential time in the conjunctival sac of the loaded drug IND. The NPs were prepared through the ionotropic gelation technique, exploiting the interaction between the positively charged amino group of CS and the negatively charged sulfonic group of SBE-β-CD. The mucoadhesive properties of the NPs were evaluated on chicken trachea and esophagus tissues using a texture analyser. The irritability effects of NPs were disclaimed with Hecam test. The developed coated NPs showed increased residential time in the conjunctival sac, displayed no irritancy or toxicity for local administration, making them an optimal and innovative drug delivery system for the treatment of anterior segment inflammation diseases. On the other hand, the uncoated NPs displayed better permeating properties since they are smaller and could be further exploited for the treatment of posterior segment diseases.

Topical treatment of diabetic retinopathy: a systematic review

Diabetic retinopathy (DR) is the most common microvascular complication in diabetes and may cause severe visual impairment. Until late stages of DR, treatment options are limited. The aim of the present review was to investigate whether changes of DR might be influenced by topical treatment with eye drops. This systematic review included both randomized and non-randomized human clinical studies on the subject. A systematic search of PubMed Medline, Embase and Scopus databases yielded 710 studies. No inclusion criteria regarding classification of DR were defined. Reference lists as well as first authors were screened for the inclusion of additional studies. Potential bias of the randomized studies was assessed using the Cochrane Risk of Bias tool. Nineteen studies suitable for inclusion were identified. Seven studies were randomized trials. These examined 11 different pharmacological groups of drugs in DR. A favourable effect of corticosteroid eye drops in diabetic macular oedema (DMO) was reported in four studies, and another study reported a positive trend. Eye drops with non-steroidal anti-inflammatory drugs were also reported to have a favourable effect in DMO, but not in non-center involving DMO. Application of neuroprotective agents was found effective in patients with pre-existing neurodegeneration in three studies. The remaining studies of DMO and DR were heterogeneous in both designs and results. Studies on treatment of DR with topical eye drops vary with regards to patient population, interventional drugs, study design, and outcome measures. Treatment of DR with eye drops was found effective in the aforementioned cases, but there is still a need for further investigations of long-term, randomized controlled trials in any of the reported pharmacological group.

Improving the solubility of vorinostat using cyclodextrin inclusion complexes: The physicochemical characteristics, corneal permeability and ocular pharmacokinetics of the drug after topical application

Vorinostat (suberoylanilide hydroxamic acid, SAHA), an FDA-approved drug for cutaneous T cell lymphoma, has antiangiogenic and anti-inflammatory activity and thus has therapeutic potential for inflammatory corneal neovascularization (CNV). However, its practical administration is limited due to its poor aqueous solubility and permeability. This study aimed to enhance the corneal permeability of SAHA by promoting its inclusion into a complex with hydroxypropyl-β-CD (HPβCD) for topical application. In phase-solubility studies, the solubility of SAHA with HPβCD and sulfobutyl ether-β-CD (SEβCD) was assessed at different temperatures, and complexation efficiencies (K) were calculated. The inclusion complexes (ICs) were prepared and characterized by differential scanning calorimetry (DSC), infrared spectrometry (IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD) after freeze-drying. The phase-solubility study showed that the complexation efficiencies of SAHA were higher in HPβCD solutions (297.35 M^-1, 115.28 M^-1 and 122.75 M^-1) than in SEβCD solutions (169.75 M^-1, 91.33 M^-1 and 96.49 M^-1) at 4 °C, 25 °C and 37 °C. HPβCD was selected for SAHA-IC preparation, and characterization revealed IC formation. SAHA existed in an amorphous state in the ICs. The ex vivo corneal permeability of SAHA was also evaluated and found to be greater when formulated as an HPβCD solution than as a suspension. Irritation assays in rabbit eyes showed that the SAHA-IC solution was not irritating after topical application. The ocular pharmacokinetics of SAHA in New Zealand White rabbits were assessed following topical administration (0.2%), and a 0.2% SAHA suspension was used as the control. Compared to its formulation as a suspension, the formulation of SAHA as an HPβCD solution increased its corneal bioavailability by more than 3-fold and its conjunctival bioavailability by more than 2-fold. Thus, IC formation was effective at improving the ocular bioavailability of SAHA. This study provides an important alternative approach for developing liquid pharmaceutical formulations of SAHA for topical ocular applications.

Cellulosic Polymers for Enhancing Drug Bioavailability in Ocular Drug Delivery Systems

One of the major impediments to drug development is low aqueous solubility and thus poor bioavailability, which leads to insufficient clinical utility. Around 70–80% of drugs in the discovery pipeline are suffering from poor aqueous solubility and poor bioavailability, which is a major challenge when one has to develop an ocular drug delivery system. The outer lipid layer, pre-corneal, dynamic, and static ocular barriers limit drug availability to the targeted ocular tissues. Biopharmaceutical Classification System (BCS) class II drugs with adequate permeability and limited or no aqueous solubility have been extensively studied for various polymer-based solubility enhancement approaches. The hydrophilic nature of cellulosic polymers and their tunable properties make them the polymers of choice in various solubility-enhancement techniques. This review focuses on various cellulose derivatives, specifically, their role, current status and novel modified cellulosic polymers for enhancing the bioavailability of BCS class II drugs in ocular drug delivery systems.

Posterior Segment Ophthalmic Drug Delivery: Role of Muco-Adhesion with a Special Focus on Chitosan

Posterior segment eye diseases (PSEDs) including age macular degeneration (AMD) and diabetic retinopathy (DR) are amongst the major causes of irreversible blindness worldwide. Due to the numerous barriers encountered, highly invasive intravitreal (IVT) injections represent the primary route to deliver drugs to the posterior eye tissues. Thus, the potential of a more patient friendly topical route has been widely investigated. Mucoadhesive formulations can decrease precorneal clearance while prolonging precorneal residence. Thus, they are expected to enhance the chances of adherence to corneal and conjunctival surfaces and as such, enable increased delivery to the posterior eye segment. Among the mucoadhesive polymers available, chitosan is the most widely explored due to its outstanding mucoadhesive characteristics. In this review, the major PSEDs, their treatments, barriers to topical delivery, and routes of topical drug absorption to the posterior eye are presented. To enable the successful design of mucoadhesive ophthalmic drug delivery systems (DDSs), an overview of mucoadhesion, its theory, characterization, and considerations for ocular mucoadhesion is given. Furthermore, chitosan-based DDs that have been explored to promote topical drug delivery to the posterior eye segment are reviewed. Finally, challenges of successful preclinical to clinical translation of these DDSs for posterior eye drug delivery are discussed.

Tailoring Terpesomes and Leciplex for the Effective Ocular Conveyance of Moxifloxacin Hydrochloride (Comparative Assessment): In-vitro, Ex-vivo, and In-vivo Evaluation

Aim

To compare the ability of both terpesomes (TPs) and leciplex (LPs) loaded moxifloxacin hydrochloride (MOX) for enhancing ocular drug conveyance.

Methods

Two separate 2¹.3¹ full-factorial trials were established to determine the influence of multiple variables upon nanovesicles properties and select the optimized formulae using Design Expert^® software. The thin-film hydration method was used to formulate TPs, while the single-step procedure was used for LPs. All formulae were characterized for their entrapment efficiency percent (EE%), particle size distribution (PS), polydispersity index (PDI), and zeta potential (ZP). Then, the optimized formulae were selected, evaluated, and compared for additional assessments.

Results

The optimized formulae TP4 and LP1 showed EE% of 84.14±0.21 and 78.47±0.17%, PS of 578.65±5.65 and 102.41±3.39 nm, PDI of 0.56±0.04 and 0.28±0.01, ZP of -12.50±0.30 and 32.50±0.50 mV, respectively. Further, LP1 showed enhanced corneal permeation across cow cornea compared to MOX solution and TP4. Besides, confocal laser scanning microscopy assessment viewed valuable infiltration from the fluoro-labeled LP through corneal layers compared to TP. LP1 showed spherical morphology and, its ability to adhere to mucus membranes was justified. Further, LP1 showed superiority over MOX solution in biofilm inhibition and eradication in addition to the treatment of infected mice with methicillin-resistant Staphylococcus aureus without any inflammatory response. Finally, the histopathological study verified the harmlessness and biocompatibility of the assembled LPs.

Conclusion

The gained outcomes confirmed the capability of utilizing LPs as a successful nanovesicle for the ocular conveyance of MOX over TPs and MOX solution.

Ocular microemulsion of brinzolamide: Formulation, physicochemical characterization, and in vitro irritation studies based on EpiOcular™ eye irritation assay

In recent years, the hydrophobic active substances have led researchers to develop new formulations to enhance bioavailability and dissolution rate; brinzolamide, a lipophilic drug belongs to carbonic anhydrase inhibitors, which cause reduction of intraocular pressure in patients suffering from glaucoma. Currently, the marketed product of brinzolamide is in the form of ocular drops; nonetheless, the conventional drops provide decreased therapeutic efficacy owing to their low bioavailability and pulsed drug release. Thus, the development of novel ocular formulations such as topical microemulsions is of high importance. In this work, the preparation of new microemulsions containing brinzolamide (0.2, 0.5 and 1% w/w) and comprised from isopropyl myristate, tween 80 and span 20 and Cremophor EL was performed. The obtained microemulsions were further characterized for their physicochemical properties. In addition, Fourier Transformed-Infrared spectroscopy was used touate the compatibility of active ingredients and components. In vitro release studies along with kinetic modeling were performed using the dialysis membrane method in simulated tear fluid. Bioadhesion studies were performed using Texture analysis. Finally, in vitro ocular irritation based on EpiOcular™ Eye Irritation Test and cytocompatibility studies was performed to examine any possible harm on ocular cells and predict in vivo safety profile.

Review of Approaches for Increasing Ophthalmic Bioavailability for Eye Drop Formulations

Ophthalmic diseases represent a significant problem as over 2 billion people worldwide suffer from vison impairment and blindness. Eye drops account for around 90% of ophthalmic medications but are limited in success due to poor patient compliance and low bioavailability. Low bioavailability can be attributed to short retention times in the eye caused by rapid tear turnover and the difficulty of drug diffusion through the multi-layered structure of the eye that includes lipid-rich endothelial and epithelial layers as well as the stroma which is high in water content. In addition, there are barriers such as tight junctional complexes in the corneal epithelium, lacrimal turnover, nasolacrimal drainage, blinking reflexes, efflux transporters, drug metabolism by ocular enzymes, and drug binding to or repulsion from conjunctival mucins, tear proteins, and melanin. In order to maximize transport through the cornea while minimizing drug loss through other pathways, researchers have developed numerous methods to improve eye drop formulations including the addition of viscosity enhancers, permeability enhancers, mucoadhesives, and vasoconstrictors, or using formulations that include puncta occlusion, nanocarriers, or prodrugs. This review explains the mechanism behind each of these methods, examines their history, analyzes previous and current research, evaluates future applications, and discusses the pros and cons of each technique.

Inclusion Complexes of Non-Steroidal Anti-Inflammatory Drugs with Cyclodextrins: A Systematic Review

Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most widely used classes of medicines in the treatment of inflammation, fever, and pain. However, evidence has demonstrated that these drugs can induce significant toxicity. In the search for innovative strategies to overcome NSAID-related problems, the incorporation of drugs into cyclodextrins (CDs) has demonstrated promising results. This study aims to review the impact of cyclodextrin incorporation on the biopharmaceutical and pharmacological properties of non-steroidal anti-inflammatory drugs. A systematic search for papers published between 2010 and 2020 was carried out using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol and the following search terms: “Complexation”; AND “Cyclodextrin”; AND “non-steroidal anti-inflammatory drug”. A total of 24 different NSAIDs, 12 types of CDs, and 60 distinct inclusion complexes were identified, with meloxicam and β-CD appearing in most studies. The results of the present review suggest that CDs are drug delivery systems capable of improving the pharmacological and biopharmaceutical properties of non-steroidal anti-inflammatory drugs.

Latanoprost-loaded cyclodextrin microaggregate suspension eye drops for enhanced bioavailability and stability

OBJECTIVE

The bioavailability of conventional eye drops is very low due to different physiological barriers. Commercial latanoprost (LAT) eye drops (Xalatan®) need to be refrigerated and protected from light. The purpose of this study was to develop novel LAT eye drops to improve ocular bioavailability and stability.

METHODS

Ophthalmic suspension containing LAT/γ-cyclodextrin (γCD) aggregates was designed and the preparation process was sufficiently studied. The prepared formulations were evaluated for pH, viscosity, osmolality, particle size, entrapment efficiency and in vitro release study. In vitro permeability study using Human Corneal Epithelial Cells and in vivo studies on rabbits were also performed.

RESULTS

LAT/γCD aggregates were formed and confirmed by scanning electron microscopy. LAT/γCD eye drops showed obvious sustained release profiles and were more stable than Xalatan®. In vitro corneal permeation study indicated LAT/γCD eye drops had no significant cytotoxicity and had higher cell permeability. In vivo precorneal retention study showed AUC_0-6 h, C_max, and mean residence time (MRT) of LAT/γCD eye drops were 3.98, 2.12, and 2.07 times higher than those of Xalatan®, respectively. In vivo ocular distribution study revealed that AUC_0-24 h, C_max, and MRT for latanoprost acid in aqueous humor exhibited 2.60-fold, 1.36-fold, and 1.99-fold increase in LAT/γCD eye drops group than those of Xalatan® group, respectively.

CONCLUSION

Cyclodextrin microaggregate suspension eye drops represent a potential strategy for enhanced bioavailability and stability of LAT.

Technological evolution of cyclodextrins in the pharmaceutical field

We herein disclose how global cyclodextrin-based pharmaceutical technologies have evolved since the early 80s through a 1998 patents dataset retrieved from Derwent Innovation Index. We used text-mining techniques based on the patents semantic content to extract the knowledge contained therein, to analyze technologies related to the principal attributes of CDs: solubility, stability, and taste-masking enhancement. The majority of CDs pharmaceutical technologies are directed toward parenteral aqueous solutions. The development of oral and ocular formulations is rapidly growing, while technologies for nasal and pulmonary routes are emerging and seem to be promising. Formulations for topical, transdermal, vaginal, and rectal routes do not account for a high number of patents, but they may be hiding a great potential, representing opportunity research areas. Certainly, the progress in materials sciences, supramolecular chemistry, and nanotechnology, will influence the trend of that, apparently neglected, research. The bottom line, CDs pharmaceutical technologies are still increasing, and this trend is expected to continue in the coming years.

Patent monitoring allows the identification of relevant technologies and trends to prioritize research, development, and investment in both, academia and industry. We expect the scope of this approach to be applied in the pharmaceutical field beyond CDs technological applications.

A shell-less hen's egg test as infection model to determine the biocompatibility and antimicrobial efficacy of drugs and drug formulations against Pseudomonas aeruginosa

A shell-less hen's egg based infection test with Pseudomonas aeruginosa was established to investigate the antimicrobial efficacy of drugs and drug formulations close to the in vivo situation. The test system using preincubated fertilized chicken eggs transferred in petri dishes was optimized with respect to the controlled local application of liquid materials and bacteria as well as the bacterial cultivation conditions. The applicability of the ex ovo infection model was confirmed with antimicrobial susceptibility tests using tobramycin, ciprofloxacin and meropenem. The validity of the ex ovo data was demonstrated by correlation with in vitro data of the CellTiter®-Blue and the microplate laser nephelometry assay. Real-time imaging of the progress of infection and the efficacy of the treatment could be realized by the MolecuLight i:X™ technique. Furthermore, in a proof-of-concept efficacy, biocompatibility and even the presence of irritants were determined side-by-side using commercial ophthalmics. In conclusion, this egg based infection model could bridge the gap between in vitro and in vivo models for the evaluation of antimicrobial susceptibility to reduce animal tests according to the 3R concept.