Carbonic anhydrase (CA) is a metalloenzyme that catalyzes the interconversion between carbon dioxide and water and dissociated ions of carbonic acid. In addition, CA performs various other functions in animals and plants, depending on the part of the living being. CAs have been found in almost all organisms. Besides, CAs are associated with several diseases, such as glaucoma, obesity, epilepsy, cancer, and so on. CAs are also involved in tumor cell growth and angiogenesis. Thus, inhibition of CA may be an attractive way of control of such diseases. Hence, CA inhibitors have been designed and developed to cure CA-associated diseases. Some examples of approved CA inhibitors are dorzolamide, methazolamide, brinzolamide, and dichlorphenamide. Furthermore, various heterocyclic scaffolds were utilized for the design of CA inhibitors. Among those, pyrazole/pyrazoline derivatives have exhibited greater potency toward CA inhibition. Hence, research that took place in the field of drug design and discovery of CA inhibition has been systematically reviewed and collated. Alongside, the structure-activity relationship has been described, followed by a description of the most potent molecules and their structural features.

We evaluated switching from brinzolamide 1% or brimonidine 0.1% to a fixed-combination of brinzolamide 1% and brimonidine 0.1%, and then determined the efficacy, safety, and satisfaction associated with these changes in glaucoma patients. This prospective, nonrandomized study evaluated a total of 31 enrolled glaucoma patients who underwent treatment with at least brinzolamide 1% or brimonidine 0.1%. Patients were administered a brinzolamide/brimonidine fixed-combination ophthalmic suspension (BBFC) after being switched from their original brinzolamide 1% or brimonidine 0.1% therapy. All other intraocular pressure (IOP)-lowering medications currently being used were continued. IOP, superficial punctate keratopathy (SPK), and conjunctival hyperemia data obtained at baseline and then at 4 and 12 weeks were evaluated. To assess the changes in treatment satisfaction, this study utilized the Treatment Satisfaction Questionnaire for Medication-9 (TSQM-9). There was a significant decrease in the mean baseline IOP from 15.7 ± 4.9 mmHg to 13.6 ± 4.4 (p = 0.001) and 13.5 ± 3.9 mmHg (p = 0.002) at 4 and 12 weeks, respectively. Evaluation of the incidence of conjunctival hyperemia or SPK score showed there were no significant changes noted at any time point. The TSQM-9 score demonstrated there was a significant increase for effectiveness after switching from brinzolamide 1% or brimonidine 0.1% to BBFC. After switching from brinzolamide 1% or brimonidine 0.1% to BBFC, there was a significant decrease in the IOP. Patients were aware of the effectiveness of switching from brinzolamide 1% or brimonidine 0.1% to BBFC.

[This retracts the article DOI: 10.2147/DDDT.S153405.].

Glaucoma is a group of eye diseases consisting of optic nerve damage with corresponding loss of field vision and blindness. Hydrogen sulfide (H2S) is a gaseous neurotransmitter implicated in various pathophysiological processes. It is involved in the pathological mechanism of glaucomatous neuropathy and exerts promising effects in the treatment of this disease. In this work, we designed and synthetized new molecular hybrids between antiglaucoma drugs and H2S donors to combine the pharmacological effect of both moieties, providing a heightened therapy. Brinzolamide, betaxolol and brimonidine were linked to different H2S donors. The H2S-releasing properties of the new compounds were evaluated in a phosphate buffer solution by the amperometric approach, and evaluated in human primary corneal epithelial cells (HCEs) by spectrofluorometric measurements. Experimental data showed that compounds 1c, 1d and 3d were the hybrids with the best properties, characterized by a significant and long-lasting production of the gasotransmitter both in the aqueous solution (in the presence of L-cysteine) and in the intracellular environment. Because, to date, the donation of H2S by antiglaucoma H2S donor hybrids using non-immortalized corneal cells has never been reported, these results pave the way to further investigation of the potential efficacy of the newly synthesized compounds.

Carbonic anhydrases (CA), having Zn2+ metal atoms, are responsible for the catalysis of CO2 and water to bicarbonate and protons. Any abnormality in the functioning of these enzymes may lead to morbidities such as glaucoma and different types of cancers including brain, renal and pancreatic carcinomas. To cope with the lack of presence of a promising therapeutic agent against these cancers, searching for an efficient and suitable carbonic anhydrase inhibitor is crucial. In the current study, ten novel 3-ethylaniline hybrid imino-thiazolidinones were synthesized and characterized by FTIR, NMR (1H, 13C), and mass spectrometry. Synthesis was carried out by diethyl but-2-ynedioate cyclization and different acyl thiourea substitutions of 3-ethyl amine. The CA (II) enzyme inhibition profile for all synthesized derivatives was determined. It was observed that compound 6e demonstrated highest inhibition of CA-II with an IC50 value of 1.545 ± 0.016 µM. In order to explore the pharmacophoric properties and develop structure activity relationship, in silico screening was performed. In silico investigations included density functional theory (DFT) studies, pharmacophore-guided model development, molecular docking, molecular dynamic (MD) simulations, and prediction of drug likeness scores. DFT investigations provided insight into the electronic characteristics of compounds, while molecular docking determined the binding orientation of derivatives within the CA-II active site. Compounds 6a, 6e, and 6g had a reactive profile and generated stable protein-ligand interactions with respective docking scores of -6.12, -6.99, and -6.76 kcal/mol. MD simulations were used to evaluate the stability of the top-ranked complex. In addition, pharmacophore-guided modeling demonstrated that compound 6e produced the best pharmacophore model (HHAAARR) compared to standard brinzolamide. In vitro and in silico investigations anticipated that compound 6e would be an inhibitor of carbonic anhydrase II with high efficacy. Compound 6e may serve as a potential lead for future synthesis that can be investigated at the molecular level, and additional in vivo studies are strongly encouraged.

Monkeypox Virus (MPXV), the causative agent of Monkeypox (MPX) disease, is an emerging zoonotic pathogen spreading in different endemic and non-endemic nations and creating outbreaks. MPX treatment mainly includes Cidofovir and Tecovirimat but they have several side effects and solely depending on these drugs may promote the emergence of drug-resistant variants. Hence, new drugs are required to control the spread of the disease. In this study, we explored the MPXV proteome to suggest repurposable drugs. DrugBank screening revealed drugs such as Brinzolamide, Dorzolamide, Methazolamide, Zidovudine, Gemcitabine, Hydroxyurea, Fludarabine, and Tecovirimat as controls. Structural analogs of these compounds were extracted from ChEMBL Database. After Molecular docking and Absorption, Distribution, Metabolism, Excretion, and Toxicity (ADMET)-based screening, we identified Zidovudine (binding affinity-5.9 kcal/mol) and a Harmala alkaloid (2S,4R)-4-(9H-Pyrido[3,4-b]indol-1-yl)-1,2,4-butanetriol (binding affinity - 6.6 kcal/mol) against L2R receptor (Thymidine Kinase). Moreover, Fludarabine (binding affinity - 6.4 kcal/mol) and 5'-Dehydroadenosine (binding affinity - 6.4 kcal/mol) can strongly interact with the I4L receptor (Ribonucleotide reductase large subunit R1). Molecular Dynamics (MD) simulations suggest all of these compounds can change the C-alpha backbone, residue mobility, compactness, and solvent accessible surface area of L2R and I4L. Our results strongly suggest that these drug repurposing small molecules are worth exploring in vivo and in vitro for clinical applications.

Carbonic anhydrase inhibitors (CAIs) are prescription drugs also used in doping to dilute urine samples and tamper with urinalyses. Dorzolamide, brinzolamide, and acetazolamide are prohibited by the World Anti-Doping Agency. Detecting CAIs and their metabolites in biological samples is crucial to documenting misuse in doping. We quantified dorzolamide, brinzolamide, acetazolamide, and their metabolites in the urine and hair of 88 patients under treatment for ocular hypertension or glaucoma. Samples of the patients' relatives were analyzed to assess potential for accidental exposure. After washing, 25 mg hair was incubated with an acidic buffer at 100 °C for 1 h. After cooling and centrifugation, the supernatant was analyzed by ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Urine (100 μL) was diluted and centrifuged before UHPLC-MS/MS analysis. Run time was 8 min through a reverse-phase column with a mobile phase gradient. MS/MS analysis was performed in a multiple-reaction monitoring mode after positive electrospray ionization. Median urinary concentration was 245 ng/mL (IQR: 116.2-501 ng/mL) for dorzolamide, 81.1 ng/mL (IQR: 35.9-125.3 ng/mL) for N-deethyl-dorzolamide, 0.77 ng/mL (IQR: 0.64 ng/mL-0.84 ng/mL) for N-acetyl-dorzolamide, 38.9 ng/mL (IQR: 20.4-79.2 ng/mL) for brinzolamide, and 72.8 ng/mL (IQR: 20.7-437.3 ng/mL) for acetazolamide. Median hair concentration was 0.48 ng/mg (IQR: 0.1-0.98 ng/mg) for dorzolamide, 0.07 ng/mg (IQR: 0.06-0.08 ng/mg) for N-deethyl-dorzolamide, 0.40 ng/mL (IQR: 0.13-1.95 ng/mL) for brinzolamide. Acetazolamide was detected in only one hair sample. Dorzolamide and brinzolamide were detected in the urine of three and one relatives, respectively. Cutoff concentrations of urinary dorzolamide and brinzolamide are necessary to preclude false positives due to contamination or passive exposure. We reported the first concentrations of brinzolamide in hair.

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.

Glaucoma is a common eye disease and a major cause of blindness. We designed brinzolamide (Brla)- and latanoprost (Ltp)-loaded nano-lipoidal carriers (NLCs) for glaucoma treatment. Brla and Ltp-loaded NLCs were designed and characterized by assessing the zeta potential, polydispersity index, X-ray diffraction and scanning electron microscopy images, and particle size. Drug release was assessed by in vitro and ex vivo methods to determine transcorneal permeation, ocular irritation, and cell viability. Moreover, Brla- and Ltp-loaded NLCs were assessed in terms of the management of raised intraocular pressure (IOP). The size of Brla- and Ltp-loaded NLCs was <200 nm, the drug entrapment efficiency was 97.5%, and the zeta potential was 35.33 mv. The transcorneal permeation levels of Blra and Ltp after 8 h were 50.5% and 49.4%, respectively; after 24 h, they were 81.4% and 84.2%, respectively. However, NLCs are not cytotoxic. Moreover, Brla+Ltp-treated NLCs effectively reduced IOP in glaucoma patients. Therefore, Brla+Ltp-loaded NLCs showed promising effects against glaucoma.

Aim: In this study, brinzolamide (BRZ) was loaded in balafilcon A silicone hydrogel soft contact lens to enhance delivery in glaucoma therapy. Materials & methods: BRZ-loaded soft contact lens was prepared by the soaking method with optimization of pH, temperature and concentration of drug loading solution. Results: At pH 7.4, loading temperature and concentration of 32°C and 3 mg/ml, respectively, enhanced drug loading capacity and release were observed. Diffusional experiments showed Higuchi model of release. BRZ loading brought no appreciable changes in the physical properties of soft contact lens, likewise, maintaining stability. Conclusion: The results demonstrated BRZ loading and delivery through silicone hydrogel soft contact lens which provides a potential alternative in glaucoma therapy.

Purpose: Our aim was to evaluate the effects of topical antiglaucomatous medications on conjunctival thickness using anterior segment optical coherence tomography (AS-OCT). Methods: Thirty eyes of 30 patients with primary open angle glaucoma, who had never used any antiglaucomatous medications, enrolled in this prospective study. Followed by a full ophthalmologic examination, the conjunctival thickness was measured before treatment and at 1, 3, and 6-month post-treatment by AS-OCT. Measurements were taken from the superior bulbar conjunctiva, 3-4 mm from the limbus. Results: The mean age of patients was 67.7 ± 8.6; fourteen cases (46.7%) were given latanoprost, 2 cases (6.7%) brinzolamide+timolol, 2 cases (6.7%) betaxolol, 4 cases (13.3%) travoprost, and 8 cases (26.7%) brimonidine. The mean baseline conjunctival thickness was 222.9 ± 38 μm, while the mean conjunctival thickness was 212.8 ± 36.0 μm in the first month, 198.2 ± 35.8 μm in the third month, and 187.5 ± 40.2 μm in the sixth month. Decrease in conjunctival thickness at each examination was statistically significantly compared to baseline. (P < 0.05) Decrease in conjunctival thickness in Latanoprost subgroup was statistically significant, whereas the decreases in other active ingredients were not. Conclusion: Topical antiglaucomatous medications especially prostaglandin analogs may affect conjunctival thickness even during the first few months. This thinning effect may be crucial for the conjunctiva, as the basis of the possible filtration surgery.

WHAT IS KNOWN AND OBJECTIVE?: Since comprehensive medication has an important role in the initial management of patients presenting with acute primary angle closure, it is necessary to analyse the effect of each drug on alleviating the disease. This study aimed to evaluate the intraocular pressure-lowering effect of brinzolamide in the sequential treatment of acute primary angle closure. METHODS: In this randomized double-blind controlled trial, a total of 131 eyes of 125 consecutive patients who presented with their first episode of acute primary angle closure were recruited and received sequential treatment. In this treatment, in the absence of remission, anti-glaucoma drugs, anterior chamber paracentesis and argon laser peripheral iridoplasty are used sequentially. The patients were randomized to receive either brinzolamide or normal saline as a placebo. The primary outcomes were decreased intraocular pressure, success rate and treatment time. RESULTS AND DISCUSSION: There was no statistically significant difference in the decreased level of intraocular pressure between the two groups at 6, 12 or 24 h after the start of treatment (p-values were 0.526, 0.206 and 0.130 respectively). The success rate and treatment time were also not significantly different between the groups. No adverse side effects of brinzolamide were observed in the brinzolamide group. WHAT IS NEW AND CONCLUSION?: In patients with a first episode of acute primary angle closure, brinzolamide did not improve the effectiveness of the sequential treatment for reducing the intraocular pressure levels or shortening the treatment time within the first 24 h of initiating therapy.

About 95% of Glioblastoma (GBM) patients experience tumor relapse as a consequence of resistance to the first-line standard chemotherapy using temozolomide (TMZ). Recent studies reported consistently elevated expression levels of carbonic anhydrase CA2 in recurrent glioblastoma and temozolomide-resistant glioblastoma stem-like cells (GSCs). Here we show that CA2 is preferentially expressed in GSCs and upregulated by TMZ treatment. When expressed in GBM cell lines, CA2 exerts significant metabolic changes reflected by enhanced oxygen consumption and increased extracellular acidification causing higher rates of cell invasion. Notably, GBM cells expressing CA2 respond to combined treatment with TMZ and brinzolamide (BRZ), a non-toxic and potent CA2 inhibitor. Interestingly, brinzolamide was more effective than the pan-CA inhibitor Acetazolamide (ACZ) to sensitize naïve GSCs and TMZ-resistant GSCs to TMZ induced cell death. Mechanistically, we demonstrated that the combined treatment of GBM stem cells with TMZ and BRZ caused autophagy of GBM cell lines and GSCs, reflected by enhanced LC3 cleavage (LC3-II) and p62 reduction. Our findings illustrate the potential of CA2 as a chemo-sensitizing drug target in recurrent GBM and propose a combined treatment of TMZ with CA2 inhibitor to tackle GBM chemoresistance and recurrence.

Angiographically silent cystoid macular edema (CME) is a rare complication from nab-paclitaxel. Here we report a 45-year-old woman with breast cancer who developed CME after several months of treatment with albumin-bound paclitaxel (nab-paclitaxel). Her visual acuity did not improve significantly with the cessation of nab-paclitaxel and intravitreal ranibizumab treatment. Then, brinzolamide eye drops were prescribed. One month later, her vision improved, with the macular edema significantly subsided. Finally, we reviewed other cases of CME induced by nab-paclitaxel that have been reported in the literature and discussed the underlying pathogenesis of nab-paclitaxel-induced CME.

We evaluated glaucoma patients for the efficacy, safety and satisfaction associated with switching from brinzolamide 1% and brimonidine 0.1% to a fixed combination of brinzolamide 1% and brimonidine 0.1%. A total of 22 glaucoma patients were enrolled and completed this prospective, nonrandomized study that evaluated patients who underwent treatment with at least brinzolamide 1% and brimonidine 0.1%. Patients on brinzolamide 1% and brimonidine 0.1% were switched to a brinzolamide/brimonidine fixed-combination ophthalmic suspension (BBFC). Evaluations of intraocular pressure (IOP), superficial punctate keratopathy (SPK) and conjunctival hyperemia were conducted at baseline and at 4 and 12 weeks. The Treatment Satisfaction Questionnaire for Medication-9 (TSQM-9) was utilized to assess the change in treatment satisfaction. At baseline and at 4 and 12 weeks, the IOP was 15.0 ± 4.1, 14.8 ± 4.1 and 14.8 ± 4.1 mmHg, respectively. There were no significant differences observed at any of the time points. However, the SPK score significantly decreased at 12 weeks, even though no significant differences were observed for the conjunctival hyperemia incidence at any of the time points. After switching from brinzolamide 1% and brimonidine 0.1% to BBFC, there was a significant increase in the TSQM-9 score for convenience and global satisfaction. Both an improvement in the degree of SPK and an increase in treatment satisfaction occurred after switching from brinzolamide 1% and brimonidine 0.1% to BBFC, even though there were sustained IOP values throughout the 12-week evaluation period.