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The limited time indorsed to face the COVID-19 emergency and large number of deaths across the globe, poses an unrelenting challenge to find apt therapeutic approaches. However, lead candidate selection to phase III trials of new chemical entity is a time-consuming procedure, and not feasible in pandemic, such as the one we are facing. Drug repositioning, an exploration of existing drug for new therapeutic use, could be an effective alternative as it allows fast-track estimation in phase II-III trials, or even forthright compassionate use. Although, drugs repurposed for COVID-19 pandemic are commercially available, yet the evaluation of their safety and efficacy is tiresome and painstaking. In absence of any specific treatment the easy alternatives such as over the counter products, phytotherapies and home remedies have been largely adopted for prophylaxis and therapy as well. In recent years, it has been demonstrated that several pharmaceutical excipients possess antiviral properties making them prospective candidates against SARS-CoV-2. This review highlights the mechanism of action of various antiviral excipients and their propensity to act against SARs-CoV2. Though, repurposing of pharmaceutical excipients against COVID-19 has the edge over therapeutic agents in terms of safety, cost and fast-track approval trial burdened, this hypothesis needs to be experimentally verified for COVID-19 patients.

This work was aimed to improve the efficacy of tacrolimus in the treatment of endotoxin-induced uveitis (EIU) using propylene glycol modified lipid vesicles termed as proglycosome nano-vesicles (PNVs). PNVs were prepared by modified film hydration method. Experimental uveitis in rabbit eye was induced by an intravitreal injection of 20 μL of the endotoxin solution containing 100 ng of lipopolysaccharide endotoxin. In vivo efficacy of PNVs was determined by studying clinical symptoms of uveitis using slit lamp examination and by quantitatively measuring levels of tumor necrosis factor-alpha, interleukin-6, leukocytes and total proteins in aqueous humor, 24 h after intravitreal injection of endotoxin. Comparison was made with healthy, untreated and tacrolimus solution treated eyes. PNVs developed were nano-sized, deformable and showed sustained release of tacrolimus over period of 12 h. In vivo results indicated statistically significant difference between the effects of PNVs in the treatment of EIU compared to tacrolimus. PNV treatment not only subsides clinical symptoms of uveitis but also prevented breakdown of blood aqueous barrier. Tacrolimus loaded PNVs are potential new topical treatment for uveitis.

In current clinical settings, frequent intravitreal (IVT) injections of anti-vascular endothelial growth factors are used due to their short in-vivo half-life and rapid clearance from the back of the eye. The IVT injections are associated with pain, risk of infection, retinal detachment, and financial burden. Biologics molecules can undergo physical, chemical, and enzymatic degradation during formulation development and in the biological environment. Moreover, the complex ocular structures also act as a rate-limiting barrier for these biologics. Thus, delivering stable and clinically relevant biologics concentration to the back of the eye is still a challenge. Compare to other drug delivery platforms, injectable in-situ gelling depot systems (IISGDs) have emerged as an effective system for biologics delivery. In this review, we have discussed various biologics used in ocular therapeutics and their associated challenges. Different routes of delivery and associated tissue barriers are also discussed. Different types of IISGDs developed to date for biologics delivery to the back of the eye were also covered. To conclude, various critical parameters related to the formulation development process and injectable depot systems that need careful consideration and further investigations were highlighted.

A posterior segment eye disease like diabetic retinopathy alters the physiology of the retina. Diabetic retinopathy is characterized by a retinal detachment, breakdown of the blood-retinal barrier (BRB), and retinal angiogenesis. An in vivo rat model is a valuable experimental tool to examine the changes in the structure and function of the retina. We propose three different experimental techniques in the rat model to identify morphological changes of retinal cells, retinal vasculature, and compromised BRB. Retinal histology is used to study the morphology of various retinal cells. Also, quantitative measurement is performed by retinal cell count and thickness measurement of different retinal layers. A BRB breakdown assay is used to determine the leakage of extraocular proteins from the plasma to vitreous tissue due to the breakdown of BRB. Fluorescence angiography is used to study angiogenesis and leakage of blood vessels by visualizing retinal vasculature using FITC-dextran dye.

Nanoparticles are potential tools for delivering therapeutics to the target site by several mechanisms. These miniaturized carriers are architected in such a way to provide passive targeting capability, which enhances the permeability and retention effect of the carrier within the biological system; simultaneously, active targeting can increase the target-specific delivery of the therapeutics through ligand attachment. Thus, ligand functionalization to the surface of the nanoparticles can be performed using proteins, peptides, polysaccharides, aptamers, and other small molecules. There are different methods for conjugating these ligands to the surface of the nanocarriers. Upon administration, these ligand-adorned nanoparticles circulate in the biological system and concentrate to the specific region for therapeutic efficacy, where the carrier is internalized to exert its biological role. Active targeting-based researches are expanding tremendously for their superior outcomes in different preclinical and clinical studies. Therefore, this chapter focuses on different methods for developing surface-engineered nanoparticles, treatment of different diseases, and diagnosis and theranostic approaches in different medical applications.

There is a great demand to utilize different in silico tools to address unwanted drug metabolism and pharmacokinetics issues in drug discovery. There is also a demand to optimize existing drug therapeutics by understanding their interactions with various transporters in the body. The cation membrane transporter is among one of the major crucial transporters within the body to regulate movement of foreign molecules/drugs across the cell membrane. The prime objective of this study is to find out the structural fingerprints within molecules to be recognized as substrate/non-substrate against human organic cation transporters (hOCTs). This study may pave the way for a more detailed understanding of the physiological and pharmacological roles of transporters as well as in predicting pharmacokinetics and pharmacodynamics in the design and development of better cationic drugs. The in silico study involving physicochemical parameter analysis revealed a trend that was distinct for substrate and non-substrate molecules present in the dataset. A hyperfine geometric distribution based strategy was also utilized for obtaining the detailed distribution of different functional moiety in substrates and non-substrates for hOCTs. Classification QSAR study by Monte-Carlo optimization and Bayesian modelling methods were used for the identification of crucial structural fingerprints important for substrate activity. Classification QSAR study with the help of Monte-Carlo optimization in case of hOCT1 revealed important structural attributes like aromatic rings with branching, two aromatic rings at one bond distance, presence of sulphur atom in the compound, etc. These seemed to have vital roles of hOCT1 substrate activity. Similarly, a Bayesian classification model was also generated which gave important fingerprints for the analysis of substrates in the case of hOCT1. Models built for hOCT2 by Monte Carlo optimization and Bayesian classification study have not given significant results from the dataset. Finally, various machine learning methods (kNN, ASNN, WEKA RF, XG-BOOST) with the combination of various descriptors were utilized for the development of models and consensus models were generated separately using the best models for both hOCT1 and hOCT2. The consensus models were utilized to predict some recently FDA approved drugs for possibly hOCT1 and hOCT2 substrates. To confirm further, the predicted compounds were docked and the analysis showed that they may bind to the different binding sites of the transporter.

The present work aimed to evaluate the efficacy of topical tacrolimus (0.01%) loaded propylene glycol (PG) modified nano-vesicles (Proglycosomes Nano-vesicles, PNVs) for the treatment of experimental dry eye syndrome (DES) in rabbits. DES was induced by topical application of atropine (1.0%) and benzalkonium chloride (0.1%) aqueous solution. PNVs treatment (PNV group) was compared with tacrolimus solution 0.01% (TAC group) and untreated group and healthy group were used as controls. PNV treated animals showed improved clinical performance with marked increase in tear production and tear break-up time (TBUT). Further, PNVs also subside ocular inflammation as evident from absence of matrix metalloprotenaise-9 and normal ocular surface temperature (32.3 ± 0.34 °C). Additionally, PNVs have positive effect on ocular and epithelial damage observed through low ocular surface staining score and improved globlet cell density. The PNV treatment was found to more effectively compared to TAC solution and most of the parameters were close to those of healthy animals. In conclusion, tacrolimus PNV formulation (0.01%) could be a potential therapy for treatment of dry eye syndrome.

Undoubtedly, various kinds of nanomaterials are of great significance due to their enormous applications in diverse areas. The structure and productivity of nanomaterials are heavily dependent on the process used for their synthesis. The synthesizing process plays a vital role in shaping nanomaterials effectively for better productivity. The conventional method requires expensive and massive thermal instruments, a huge volume of reagents. This paper aims to develop an Automatic Miniaturized Temperature Controller (AMTC) device for the synthesis of nickel oxide (NiO), copper oxide (CuO) nanoparticles, and nanomicelles. The device features a low-cost, miniaturized, easy-to-operate with plug-and-play power source, precise temperature control, and geotagged real-time data logging facility for the producing nanoparticles. With a temperature accuracy of ± 2 °C, NiO and CuO nanoparticles, and nanomicelles are synthesized on AMTC device, and are subjected to different characterizations to analyze their morphological structure. The obtained mean size of NiO and CuO is 27.14 nm and 85.13 nm respectively. As a proof-of-principle, the synthesized NiO and CuO nanomaterials are validated for electrochemical sensing of dopamine, hydrazine, and uric acid. Furthermore, the study is conducted, wherein, Dexamethasone (Dex) loaded nanomicelles are developed using AMTC device and compared to the conventional thin-film hydration method. Subsequently, as a proof-of-application, the developed nanomicelles are evaluated for transcorneal penetration using exvivo goat cornea model. Ultimately, the proposed device can be utilized for performing a variety of controlled thermal reactions on a minuscule platform with an integrated and miniaturized approach for various applications.

Over the past decades, click chemistry has attracted significant attention in the preparation of cross-linked biopolymer-based hydrogels for biomedical applications. The click hydrogels offer various benefits, such as simple preparation methods, better physical stability, improved mechanical properties, ability to deliver biologics, minimal invasive administration at the target sites and sustained drug-release properties. Moreover, the use of biopolymers enhances the biodegradability, biocompatibility and nonimmunogenic properties of these hydrogels. The chapter provides a comprehensive overview of the recent advancements in click-chemistry strategies for fabricating biopolymer-based hydrogels and their drug-delivery applications.

In current clinical settings, frequent intravitreal (IVT) injections of anti-vascular endothelial growth factors are used due to their short in-vivo half-life and rapid clearance from the back of the eye. The IVT injections are associated with pain, risk of infection, retinal detachment, and financial burden. Biologics molecules can undergo physical, chemical, and enzymatic degradation during formulation development and in the biological environment. Moreover, the complex ocular structures also act as a rate-limiting barrier for these biologics. Thus, delivering stable and clinically relevant biologics concentration to the back of the eye is still a challenge. Compare to other drug delivery platforms, injectable in-situ gelling depot systems (IISGDs) have emerged as an effective system for biologics delivery. In this review, we have discussed various biologics used in ocular therapeutics and their associated challenges. Different routes of delivery and associated tissue barriers are also discussed. Different types of IISGDs developed to date for biologics delivery to the back of the eye were also covered. To conclude, various critical parameters related to the formulation development process and injectable depot systems that need careful consideration and further investigations were highlighted.

The present study aimed at the development and evaluation of tacrolimus gellan gum nanoparticles (TGNPs) for the effective management of dry eye disease (DED) following topical application. TGNPs were developed by ionotropic gelation between gellan gum and aluminum chloride. Developed TGNPs were nanosized (274.46 ± 8.90 nm) with high % encapsulation efficiency (74.2 ± 2.4%) and loading capacity (36.14 ± 1.7%). The nanosize and spherical morphology of TGNPs was confirmed by transmission electron microscopy (TEM) and atomic force microscopy (AFM). Fourier transform infrared spectroscopy (FTIR) revealed no interaction between drug and GG. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) confirms the conversion of crystalline tacrolimus to amorphous post encapsulation in the nanoparticle. TGNPs showed prolonged drug release throughout 12 h and higher pre-corneal retention compared to tacrolimus solution. HET-CAM studies, histopathological evaluation, and Draize test confirmed the safety of the formulation for ocular use. Further, the pharmacodynamic studies using experimental DED in rabbits showed that TGNPs are effective in treating symptoms of DED. In conclusion, topical delivery of TGNPs could hold potential for efficient management of DED.

The study aimed to evaluate the intraocular pharmacokinetics and efficacy of aflibercept after subconjunctival injection in animal models for treating choroidal neovascularization (CNV) associated with Age-Related Macular Degeneration (AMD). New Zealand albino rabbits received aflibercept (2000 μg/50 μl) in one eye, and the other eye was used as control. At 7, 14, 21 and 28 days, the animals were sacrificed to dissect the ocular tissues, and serum was collected at 1hr, 3 h, 1, 7, 14, 21 and 28 days. The concentration of aflibercept in various ocular tissues and serum were measured using the immunoassay technique. The concentration maximum (Cmax) at the Retinal Pigment Epithelium (RPE)-choroid complex and retina in treated eyes was 261.55 and 33.83 ng/gm, respectively. The area under the curve (AUC0-last) for RPE-Choroid and retina were 2094.02 and 290.33 days. ng/gm respectively. The time maximum (Tmax) for the ocular tissues was reached on day 7. In the vitreous humour, a lower level of aflibercept was retrieved. The Cmax (1766.84 ng/ml) in the serum was reached on day 1, followed by a decline in the concentration till the end of the study period. In treated eyes, the levels of aflibercept in most of the ocular tissues were maintained for at least 21 days above the invitro IC50 concentration. The results of the efficacy study show that subconjunctival aflibercept could reach the therapeutic target to inhibit CNV. The subconjunctival aflibercept could be a less invasive route for treating CNV with AMD.

The purpose of this study was to develop, characterize and evaluate novel water soluble formulation for its topical and intrastromal application. Natamycin complexed with cyclodextrin was characterized by Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The complexed powder was used to formulate 1% w/v aqueous natamycin formulation (Natasol 1%) for topical use. The developed formulation was subjected to stability testing at various conditions. Single and multi-dose trans-corneal permeation of Natasol 1% was evaluated in New Zealand Albino rabbits in comparison with marketed 5% natamycin suspension. Sterile unpreserved Natasol (0.01% w/v natamycin) formulation was also developed for intrastromal injection. Both formulations were evaluated for the ocular toxicity. FTIR and DSC studies revealed successful complexation of natamycin that further protected the degradation at various stability conditions. Single dose trans-corneal permeation studies revealed that Natasol 1% attained Cmax at one hr and maintain its intraocular concentration 5 and 2.5 times higher at 4th and 6th hr compared to 5% natamycin suspension. Multi-dose kinetics revealed the steady state pharmacokinetics after hourly and two hourly dosing schedules. Topical Natasol 1% and sterile unpreserved Natasol 0.01% intrastromal injection, did not show any ocular toxicity in the animals. To conclude, the newly developed topical 1% w/v natamycin formulation was found to be non-inferior to 5% natamycin topical suspension. It is expected to increase patient compliance for the treatment of fungal keratitis.

Infectious endophthalmitis is an important cause of vision loss worldwide. This entity most often occurs as a complication of intraocular surgery especially following cataract surgery or intravitreal injection. Endophthalmitis is regarded as a serious complication following ocular surgery and the final visual outcome is fundamentally contingent on timely recognition and intervention. Intravitreal and oral antibiotics in combination with pars plana vitrectomy or vitreous aspiration remain the mainstay in the management of endophthalmitis. However, significant inflammation may persist even after sterilization of the intraocular cavities with appropriate antibiotics resulting in failure of treatment. This forms the basis for the use of intravitreal corticosteroids as an adjuvant to antibiotics in the management of infectious endophthalmitis. In the index manuscript, we review the existing literature to determine the role of intravitreal corticosteroids as an adjuvant to antibiotics in treating infectious endophthalmitis, and discuss their beneficial effects and controversial concerns.

Uveitis is an important cause of vision loss worldwide due to its sight-threatening complications, especially cystoid macular edema, as well as choroidal neovascularization, macular ischemia, cataract, and glaucoma. Systemic corticosteroids are the mainstay of therapy for noninfectious posterior uveitis; however, various systemic side effects can occur. Intravitreal medication achieves a therapeutic level in the vitreous while minimizing systemic complications and is thus used as an exciting alternative. Corticosteroids, antivascular endothelial growth factors, immunomodulators such as methotrexate and sirolimus, and nonsteroidal anti-inflammatory drugs are currently available for intravitreal therapy. This article reviews the existing literature for efficacy and safety of these various options for intravitreal drug therapy for the management of noninfectious uveitis (mainly intermediate, posterior, and panuveitis).

The important causes of loss of vision are ocular infections, including keratitis and conjunctivitis. Attaining an adequate concentration of topically applied antibiotics to prevent or treat infections within the cornea is challenging. The study aimed to design and develop a drug-eluting polymeric contact lens for the effective delivery of moxifloxacin (MF) and dexamethasone (DM). The polymeric contact lens was prepared using chitosan, glycerol, and polyethylene glycol. MF and DM were loaded into the contact lens, both separately and in combination. The MF and DM loaded contact lenses were characterized for thickness, swelling index, surface topography, and mucoadhesion strength. Furthermore, studies were performed to understand the in vitro drug release behavior, ex vivo corneal permeation, and in vitro and in vivo antimicrobial activity. The drug-loaded contact lens was compared with the standard drug solutions. The physical characteristics of the polymeric contact lens were similar to the commercially available contact lens. Compared to the topically applied standard drug solutions, the drug-loaded contact lens showed significantly (p 0.05) greater corneal drug distribution after 24 h incubation. In vitro and in vivo antimicrobial activity of the MF loaded contact lens was superior to the standard drug solution. In vivo drug distribution studies showed greater tissue concentration of MF in cornea, sclera, and aqueous humor with contact lens application compared with drug solutions. Overall, the polymeric contact lens was efficient in delivering MF and DM at required therapeutic concentrations. The findings from the present study show that drug-eluting contact lenses could be used in post-operative conditions to prevent ocular infections.

To study the protection offered by empty liposomes (LPs) alone against acrolein-induced changes in urothelial cell viability and explored uptake of LPs by primary (rat) urothelial cells. Acrolein was used as a means to induce cellular damage and reduce urothelial cellular viability. The effect of acrolein or liposomal treatment on cellular proliferation was studied using 5-bromo-2′-deoxy-uridine assay. Cytokine release was measured after urothelial cells were exposed to acrolein. Temperature-dependent uptake study was carried out for fluorescent-labeled LPs using confocal microscopy. Liposome pretreatment protected against acrolein-induced decrease in urothelial cell proliferation. LPs also significantly affected the acrolein-induced cytokine (interferon-gamma) release offering protection to the urothelial cells against acrolein damage. We also observed a temperature-dependent urothelial uptake of fluorescent-labeled LPs occurred at 37 °C (but not at 4 °C). Empty LPs alone provide a therapeutic efficacy against acrolein-induced changes in urothelial cell viability and may be a promising local therapy for bladder diseases. Hence, our preliminary evidence provides support for liposome-therapy for urothelial protection and possible repair.

Uveitis is a sight threatening inflammatory disorder that affects all ages and remains a significant cause of visual loss. Inflammatory activity plays an important role in the whole pathogenesis of uveitis. Treatment of uveitis is mainly driven by corticosteroids that have potential side effects. Recent investigations demonstrated that tacrolimus inhibits T-cell proliferation and suppresses release of inflammatory cytokines. Since tacrolimus is a definite immunosuppressive agent, and since inflammatory process has been involved in uveitis, the compound must have effect on the progression of uveitis through reduction in inflammatory activity. Even results of the clinical trials demonstrate that tacrolimus have useful role in treatment of sight threatening uveitis that is refractory to other therapy. Studies also indicate that long term use of tacrolimus is well tolerated. However, its use in uveitis is limited because of its poor physico-chemical properties including poor aqueous solubility and high molecular weight (822 Da). Therefore, we have proposed that tacrolimus nanoemulsion administered topically is a promising therapeutic approach to treat uveitis. Based on previous evidences, we have hypothesized that nanoemulsion formulation of tacrolimus can improve efficacy and safety profile of tacrolimus.

We hypothesize organic cation transporters (OCT) may have a potential role in determining the pharmacokinetics and toxicity of organic cation drugs applied topically. Hence, in the present in vivo study, we attempted to evaluate the role of OCT in modulating the transport of its substrates after topical application. New Zealand albino rabbits of either sex were used. Transcorneal penetration of OCT substrates tetraethylammonium and metformin after single instillation was evaluated in the absence and presence of OCT blockers (quinidine and atropine). Aqueous humor (AH) samples were collected through paracentesis amounting to 70–100 μl under topical anesthesia at various time intervals. The samples were subjected for estimation of both substrate as well as blocker concentrations using liquid chromatography mass spectrometry. Topical pre-treatment (30 min before substrate) of OCT blockers significantly decreased the transcorneal penetration of OCT substrates after single topical administration. The levels of blockers reaching AH in the presence of substrates were also modulated at 60 min after its administration as compared with its control. OCT are functionally active in the uptake of their substrates from tear to AH. Therefore, OCT in the corneal epithelium may be positioned from apical to basolateral. When administering their substrates/blockers topically, both may be competing for OCT for their uptake across the cornea, thereby decreasing the corneal penetration. Hence OCT can have a potential pharmacokinetic role in modulating the ocular bioavailability of their substrates administered topically, which are used as ocular therapeutics.

The potent immunosuppressive effect of systemic tacrolimus is limited by the high incidence of severe adverse effects, including nephrotoxicity and hypertension. Intravesical application of tacrolimus is hindered by its poor aqueous solubility, justifying the search for novel delivery platforms such as liposomes. We evaluated the pharmacokinetics of tacrolimus encapsulated in liposomes (lipo-tacrolimus), which is being developed as a potential orphan drug indication for hemorrhagic cystitis.A single dose of lipo-tacrolimus was instilled in the bladder with the rat under anesthesia. Also, tacrolimus was instilled intravesically or injected intraperitoneally in other rat groups. The tacrolimus dose was constant in all formulations at 200 μg/ml. At different times blood, urine and bladder samples were collected and stored at -80C until analysis. Tacrolimus levels in samples were analyzed using microparticle enzyme immunoassay II.The AUC of lipo-tacrolimus in serum at 0 to 24 hours was significantly lower than that of tacrolimus instillation or injection. Noncompartmental pharmacokinetic data analysis revealed maximum concentration of lipo-tacrolimus and tacrolimus in serum and urine at 1 and at 2 hours, respectively. Urine AUC(0-24) after intravesical administration was significantly higher than in the intraperitoneal group (p0.05). Bladder tacrolimus AUC(0-24) did not differ significantly between the groups.Single dose pharmacokinetics revealed that bladder instillation of liposome encapsulated tacrolimus significantly decreased systemic exposure to instilled tacrolimus as well as vehicle related toxicity. Intravesical liposomal tacrolimus may be a promising approach as an orphan drug indication for hemorrhagic cystitis.

Background: This paper describes the synthesis of thiolated chitosan-based hydrogels with varying degrees of crosslinking that has been utilized to modulate release kinetics of two clinically relevant FDA-approved anti-VEGF protein drugs, ranibizumab and aflibercept. These hydrogels have been fabricated into disc shaped structures for potential use as patches on ocular surface. Methods: Protein conformational changes and aggregation after loading and release was evaluated by circular dichroism (CD), steady-state tryptophan fluorescence spectroscopy, electrophoresis and size-exclusion chromatography (SEC). Finally, the capacity of both released proteins to bind to VEGF was tested by ELISA and surface plasmon resonance (SPR) technology. Results: The study demonstrates the versatility of thiolated chitosan-based hydrogels for delivering proteins. The effect of various parameters of the hydrogel on protein release kinetics and mechanism of protein release was studied using the Korsmeyer-Peppas release model. Furthermore, we have studied the stability of released proteins in detail while comparing it with non-entrapped proteins under physiological conditions to understand the effect of formulation conditions on protein stability. Conclusions: The disc-shaped thiolated chitosan-based hydrogels provide a potentially useful platform to deliver ranibizumab and aflibercept for the treatments of ocular diseases such as wet AMD, DME and corneal neovascularization

Utilization of the full clinical potential of many novel therapeutic proteins designed for diseases affecting the posterior segment of the eye has often been limited because of their inherent instability and the difficulty in overcoming various ocular barriers. Intravitreal injection is currently the only approved mode of administration, although it is suboptimal because it is painful and has to be done every 1-2 months as a result of high protein clearance rates from the vitreous humor. In this review, we discuss the status of protein drug delivery to back of the eye in terms of novel protein drugs developed, physiological barriers encountered, strategies for carrier design to overcome these limitations, and protein stability. We focus on the most promising approaches as well as on current shortcomings.

The anti-vascular endothelial growth factor (VEGF) agents such as ranibizumab (Lucentis®) and aflibercept (EyLea®) are currently used as monthly or bimonthly intravitreal injections to treat potentially retinal diseases such as wet age-related macular degeneration (AMD) or diabetic macular edema (DME). Because of the complications associated with repeated intra-vitreal injections, there is considerable interest in developing a sustained delivery system. The purpose of this study was to examine the stability of both therapeutic proteins under physiological conditions as well as when incorporated into drug delivery systems (DDS). First, thermotropic properties in physiological conditions and at different pH values were evaluated by differential scanning calorimetry (DSC) to determine the protein denaturation temperature. Second, the effects of pH and incubation time on conformational changes and aggregation were evaluated by circular dichroism (CD), steady-state tryptophan fluorescence spectroscopy, and size-exclusion chromatography (SEC). Also, the ability of both proteins to bind to VEGF was tested in the aforementioned experimental conditions for up to 30 days. Finally, we investigated the stability of both proteins after a rapid screening method that simulates the first homogenizing step during the protein microencapsulation process. This method allowed the development of stable ranibizumab and aflibercept formulations that may be useful to entrap these proteins into microparticles selecting the most convenient organic solvent and protein stabilizers.

Chromatographers often develop problems while optimizing a method for the quantification of quaternary ammonium compounds in ESI-MS/MS. Intransigency observed in quaternary ammonium compounds to undergo the classical molecular adduct formation [M+H]+ in ESI-MS/MS reduces confidence among chromatographers while working with unit mass resolution. In this study, we provide the evidence for an exceptional rule followed by mono- and di-quaternary ammonium compounds in ESI-MS/MS in the precursor ion formation. Under ESI conditions mono- and di-quaternary ammonium compounds form molecular ions with the formula of m q / z q rather than ( m + z )/ z . Formation of m q / 2 is observed for di-quaternary ammonium compounds in precursor ion scan and m q / 1 in product ion scan, if loss of one of the quaternary charge occurs during CID. In di-quaternary ammonium compounds, this process can also result in the formation of fragment ions with higher mass as compared to precursor ion. Hydrophilic interaction liquid chromat...

Intravesical (local) therapy for diseases emanating from the bladder is similar to the commonplace management of ocular diseases using eyedrops. The existing intravesical therapy involves administering dosage forms directly into the bladder (through a catheter). This mode of treatment is routine in the bladder cancer by instillation of bacillus Calmette–Guerin to provoke the body's own natural defenses against invasion by proliferating cancer cells in the bladder. Although convenient, the conventional routes of administration for treating diseases such as interstitial cystitis/painful bladder syndrome (IC/PBS) and overactive bladder (OAB) are less acceptable to patients owing to side effects, which may further exacerbate the disease symptoms. Intravesical therapy has demonstrated varying degrees of efficacy and safety in treating IC/PBS and OAB. In recent years, intravesical delivery of biotechnological products including neurotoxins using a liposome platform demonstrated immense promise for lower urinary tract symptoms. This review considers the current status of intravesical therapy in lower urinary tract diseases with special attention to novel drug-delivery systems.

In this review we discuss insights into therapeutic stratagems that can selectively target the choroid, retinal cells and vitreoretinal space for the treatment of vision-threatening vascular degenerative disorders of the posterior eye. Despite the relative success of these novel drugs, new problems related to its delivery remain. Systems carrying drugs to the target site, such as nanoparticles, liposomes, vectosomes, spanlastics, micelles, dendrimers and implants are also discussed. Further, we also consider drug penetration enhancement approaches along with cutting-edge strategies for regaining vision during vision-threatening vascular degenerative disorders of the eye. Finally, challenges, such as ocular or even systemic complications associated with use of prolonged therapies and future prospects, such as combination of approaches with multidisciplinary integration to optimize delivery to the posterior eye are also addressed.

Various static and dynamic ocular barriers in conjunction with membrane transporters pose a significant challenge for ocular drug therapy. These challenges present unique opportunities for understanding the barriers and overcoming it using novel/innovative drug delivery systems. Recently in response to advent of potent and versatile therapeutic agents, the diversity of conventional ocular formulations has gradually evolved, extending well beyond simple solutions, suspensions and ointments. The field includes a variety of innovative carriers that have shown the capacity to encapsulate wide variety of drugs and macromolecules and maintain extended drug effect in targeted tissues. Vesicular carriers, polymeric and lipid nanoparticles, dendrimers, nanoplexes, nanoemulsions, cubosomes, nanoassemblies, nanomicelles and various hybrid hydrogels as well as drug delivery enhancement devices have been widely explored to overcome various hurdles. This chapter presents an overview about the importance of understanding the blood ocular barriers for developing strategies for appropriate drug delivery systems and applications of innovative carriers for ocular delivery of drugs or macromolecules.

Introduction: Diabetic Retinopathy (DR) is one of the most common causes of blindness among the working population worldwide. Clearly, there is an unmet clinical need to find better treatment options for DR. Areas covered: The literature search was conducted on PubMed with no limitation on language or year of publication. The review focuses on the clinically used drugs/proteins along with a brief background on the pathophysiology of DR. The major focus of this review revolves around three treatment approaches involving drugs/proteins, drug delivery formulations and drug delivery devices. In each category, major advances are discussed along with the possible solutions. We have also discussed the various modes of administration that are currently being evaluated in the clinic. An attempt has been made to address the potential targeted site of action for DR drug delivery, and also to understand the role of Blood Retinal Barrier (BRB). Expert Opinion: In the current scenario, although there have been some advances in the drug delivery devices for delivering drugs/proteins, there are still challenges to be overcome with regard to the particulate systems. For long-term success of DR therapeutics, research options should consider taking into account the 3Ds (drug, delivery and devices). Accepted version

Background: The functional and molecular alterations of nerve growth factor (NGF) and Prostaglandin E2 (PGE2) and its receptors were studied in bladder and urine in streptozotocin (STZ)-induced diabetic rats. Methodology/Principal Findings: Diabetes mellitus was induced with a single dose of 45 mg/kg STZ Intraperitoneally (i.p) in female Sprague-Dawley rats. Continuous cystometrogram were performed on control rats and STZ treated rats at week 4 or 12 under urethane anesthesia. Bladder was then harvested for histology, expression of EP receptors and NGF by western blotting, PGE2 levels by ELISA, and detection of apoptosis by TUNEL staining. In addition, 4-hr urine was collected from all groups for urine levels of PGE2, and NGF assay. DM induced progressive increase of bladder weight, urine production, intercontraction interval (ICI) and residual urine in a time dependent fashion. Upregulation of Prostaglandin E receptor (EP)1 and EP3 receptors and downregulation of NGF expression, increase in urine NGF and decrease levels of urine PGE2 at week 12 was observed. The decrease in ICI by intravesical instillation of PGE2 was by 51% in control rats and 31.4% in DM group at week 12. Conclusions/Significance: DM induced hyposensitive underactive bladder which is characterized by increased inflammatory reaction, apoptosis, urine NGF levels, upregulation of EP1 and EP3 receptors and decreased bladder NGF and urine PGE2. The data suggest that EP3 receptor are potential targets in the treatment of diabetes induced underactive bladder. © 2014 Nirmal et al.