Olopatadine (OLO) is a second-generation antihistamine approved for the treatment of allergic conjunctivitis as ophthalmic and nasal solutions. Due to its intrinsic absorption in the near-UV region (approximately 300 nm), OLO may be susceptible to photodegradation and understanding this behavior is essential for ensuring the quality and safety of OLO-containing pharmaceutical formulations. The forced photodegradation of OLO was investigated under UV/Vis irradiation (300-800 nm) over a wide pH range. Photodegradation kinetics was evaluated using a selective LC-UV method. OLO degradation followed first-order kinetics, with rate constants ranging from 3.45 × 10[-5] to 6.91 × 10[-5] s[-1], corresponding to degradation levels in the range 45.54-81.95%. Photodegradation products were characterized using UHPLC-HRMS/MS, leading to the identification of twelve, including seven previously unreported compounds. Seven degradants were isolated by preparative LC-UV and their structures were confirmed by NMR spectroscopy, including three newly reported compounds. The potential toxicity of all identified photodegradants was evaluated using the in silico tools OSIRIS Property Explorer and Toxtree. Five products were predicted to exhibit reproductive toxicity and irritation potential, whereas one compound showed a potential tumorigenic risk. Overall, this study provides comprehensive insight into the photostability of OLO and the formation of its photodegradation products.

Medication safety must be carefully considered during pregnancy because of the potential risks to the fetus. Allergic diseases during pregnancy, oral second-generation antihistamines, such as fexofenadine and olopatadine, are often used when topical agents are insufficiently effective. However, there are limited data on their teratogenic risk, particularly in the Japanese population. A cohort study was conducted using data from Japanese teratogenicity information services at two institutions: Toranomon Hospital and the National Center for Child Health and Development. Outcomes in pregnant women exposed to fexofenadine or olopatadine during the first trimester were compared with those in controls exposed to nonteratogenic drugs. The primary endpoint was the incidence of major birth defects defined by the EUROCAT criteria. Secondary outcomes included preterm birth and low birth weight. Logistic regression analyses were performed with adjustment for maternal age, alcohol consumption, smoking, and comorbidities. In total, 1473 eligible pregnancies for the analysis of major birth defects were included. Major birth defects occurred in 1.8% of the fexofenadine group (n = 231) and 3.0% of the olopatadine group (n = 186), showing no significant increase compared with 1.8% of the control group (n = 1056). Logistic regression showed no association between either antihistamine and major birth defects, preterm birth, or low birth weight after adjustment. No consistent pattern of anomalies was identified. This study found no evidence that exposure to fexofenadine or olopatadine in the first trimester increases the risk of major birth defects. These second-generation antihistamines appear to be relatively safe in pregnant women with allergic conditions.

Biologics targeting interleukin-17 (IL-17) are widely used for moderate to severe psoriasis with great efficiency. Nonetheless, their usage has sporadically resulted in paradoxical reactions, such as eczema, sarcoidosis-like eruptions, alopecia areata, and pyoderma gangrenosum. Here, we report a case of temporary facial eczema to secukinumab with a score of 5 on the Naranjo scale, which suggests a probable drug side effect. The patient was a 32-year-old Chinese male with a history of chronic plaque psoriasis for 5 years. He was previously treated with topical steroids, calcipotriol, narrowband ultraviolet B phototherapy, and oral traditional Chinese medicine intermittently since 2020. In January of 2025, his psoriasis exacerbated and was not well controlled. The patient underwent an initial regimen of 300 mg secukinumab once weekly for 4 weeks, with significant psoriasis area and severity index (PASI) improvement, and was scheduled to continue maintenance therapy on a regimen of every 4 weeks. However, in the seventh week of the secukinumab treatment course, the patient's face developed diffuse, swollen, erythematous patches that had almost coalesced into sheets. The surface is smooth, without scales, blisters, or exudation, and accompanied by mild itching. Lab tests show elevated alanine aminotransferase (ALT) at 83.2 U/L (normal range: 9-50 U/L), slightly increased direct bilirubin at 8.48 μmol/L (normal range: 0-8.0 μmol/L). Other lab tests showed no significant abnormalities. After oral compound glycyrrhizin, olopatadine hydrochloride, triprolidine hydrochloride, and topical pimecrolimus for a week, his facial lesions were completely cleared. Liver function tests normalized following a 2-week course of polyenphosphatidylcholine. The patient delayed secukinumab administration by 2 weeks and continued 300 mg secukinumab administration on a regimen of every 4 weeks. No recurrence of similar rash or other adverse effects was observed during the subsequent follow-up period over 5 months. It is concluded that eczema could be induced temporarily by secukinumab, and maybe continued application.

Olopatadine hydrochloride, a second-generation selective histamine H1 receptor antagonist, is an effective anti-allergic agent. This study evaluated the pharmacokinetics and bioequivalence of two olopatadine hydrochloride tablet formulations in healthy Chinese subjects under fasting (n = 24) and fed (n = 24) conditions. A single-center, randomized, open-label, single-dose, two-way crossover study was conducted, in which 48 subjects were randomized to receive 5 mg of the test or reference formulation, followed by a 7-day washout period. Blood samples were collected at predefined intervals up to 24 h post-dose, and olopatadine plasma concentrations were measured using a validated liquid chromatography-tandem mass spectrometry method. The results demonstrated no significant differences in the pharmacokinetic profiles between the test and reference formulations under fasting or fed conditions. The 90% confidence intervals (CIs) for the ratio of geometric means of Cmax, AUC0-t, and AUC0-∞ of olopatadine hydrochloride under both conditions were within the bioequivalence range of 0.80-1.25. A high-fat diet delayed olopatadine hydrochloride absorption, leading to a reduction in Cmax to approximately 60% of the fasting value and a decrease in AUC to 85%-90%. No serious adverse events occurred, and safety profiles were comparable between formulations. This research confirmed the bioequivalence and similar safety of the generic olopatadine hydrochloride tablets to the reference formulation.

Allergic rhinitis (AR) leads not only to significant nasal obstruction and ocular symptoms but also, by affecting the entire respiratory epithelium, causes combined damage to the Eustachian tube and middle ear, resulting in exudative otitis media (EOM). To evaluate the clinical features of EOM of allergic origin and to compare treatment regimens targeting allergic inflammation - with the goal of restoring Eustachian tube function and middle ear drainage - 329 patients with confirmed allergic rhinitis were examined. Following otorhinolaryngological and audiological evaluations, pathology of the middle ear and Eustachian tube was identified in 51% of cases (168 individuals). Interestingly, 16% of these patients subjectively reported no hearing loss or sensation of ear fullness, despite objective confirmation of pathology. To assess the comparative effectiveness of different AR therapy regimens and their impact on middle ear and Eustachian tube pathology, the 168 affected patients were divided into four parallel groups: Main group (41 patients): treated with a fixed-dose combination of mometasone furoate and olopatadine hydrochloride (Rialtris); Control group 1 (45 patients): received intranasal monotherapy with mometasone furoate; Control group 2 (41 patients): treated with the oral antihistamine levocetirizine; Control group 3 (41 patients): received combination therapy of intranasal mometasone furoate and oral levocetirizine. To monitor the restoration of auditory tube function and middle ear pneumatization, tympanometry and micro-otoscopy were performed on days 1, 7, 14, and 30. All treatment regimens positively influenced Eustachian tube dysfunction. The combination of intranasal mometasone furoate and oral levocetirizine demonstrated superior efficacy, with a statistically significant difference (p=0.01, CO = -33.60; 95% CI -61.05 to -6.15). Due to the accelerated recovery of Eustachian tube function and restoration of its drainage capabilities, the need for invasive middle ear drainage procedures (e.g., shunting, tympanostomy) was eliminated in the group receiving the fixed intranasal combination of mometasone furoate and olopatadine hydrochloride. This fixed-dose combination appears to be the optimal treatment for allergic Eustachian tube dysfunction, owing to its direct endonasal action on the respiratory epithelium at the Eustachian tube, allowing for rapid restoration of middle ear ventilation.

This systematic review and meta-analysis aimed to compare the efficacy and safety of olopatadine and rupatadine in the treatment of allergic rhinitis (AR). By synthesizing data from randomized controlled trials (RCTs), this study aimed to evaluate symptom reduction, specifically in terms of the Total Nasal Symptom Score (TNSS), and assess the incidence of adverse effects between these two second-generation antihistamines. A comprehensive literature search was conducted in PubMed, Google Scholar, Web of Science, Embase, and Cochrane databases from November 2024 to February 2025. Studies were selected based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Clinical trials comparing olopatadine and rupatadine in AR patients were included, with a focus on TNSS reduction and adverse event incidence. The Jadad scale was used for quality assessment. Data were analyzed using the DerSimonian and Laird random effects model, with mean differences and risk ratios (RR) calculated. Heterogeneity was assessed using the chi-square test and I[2] statistic. A total of four RCTs involving 304 patients (153 in the olopatadine group, 151 in the rupatadine group) met the inclusion criteria. Olopatadine demonstrated superior TNSS reduction (mean difference: 2.51; 95% CI: 1.58 to 3.44; p<0.0001), with low heterogeneity (I[2]=0%). Adverse events were comparable between groups (RR=0.66; 95% CI: 0.29-1.50; P=0.33), with dry mouth, headache, and mild sedation being the most frequently reported. Olopatadine showed greater efficacy in reducing symptoms of allergic rhinitis compared to rupatadine, while both drugs had similar safety profiles. These findings suggest that olopatadine may be preferred for more symptom relief, though larger trials are needed for further validation.

Background: The incorporation of polymers into drug delivery vehicles has been shown to be an effective strategy to prolong the residence time of active ingredients in the precorneal tear film and to increase ocular bioavailability. Objectives: The aim of this study was to develop novel, viscous eye drops containing olopatadine (OCH) as the active ingredient, polysaccharides hydroxypropyl guar gum (HPG), and sodium hyaluronate (SH), individually, and in combination as functional polymers. Methods: Viscous eye drops containing 0.1% OCH in combination with HPG (0.25%) and SH (0.4%), were prepared and evaluated for their physicochemical properties, rheological behavior, mucoadhesion, and preliminary stability. A novel rheological method was used to evaluate the resistance of the eye drops under simulated blinking conditions. In vivo efficacy was evaluated using an ocular itch test in mice to compare the formulations with a commercial product. Results: The formulations remained stable and transparent, with physicochemical parameters within acceptable ranges. Rheological studies confirmed pseudoplastic flow, with the HPG-SH combination exhibiting enhanced viscosity and shear-thinning properties for prolonged retention in the eye. Mucoadhesion was highest in SH-HPG formulations. During simulated blinking cycles, eye drops containing a combination of SH and HPG polymers fully regained their initial viscosity during the resting periods. Preliminary stability studies indicate that the formulated eye drops exhibit satisfactory physicochemical stability under various storage conditions. In vivo, OCH-SH and OCH-HPG-SH drops provided prolonged antipruritic and analgesic effects compared to the reference product. Conclusions: Polysaccharide-based innovative formulations improve OCH retention, enhancing therapeutic efficacy and patient compliance in the treatment of allergic conjunctivitis.

Canada’s Drug Agency (CDA-AMC) recommends that Ryaltris should not be reimbursed by public drug plans for the symptomatic treatment of moderate-to-severe seasonal allergic rhinitis and associated ocular symptoms in adults, adolescents, and children aged 6 years and older. WHY DID CDA-AMC MAKE THIS RECOMMENDATION? • Evidence from 3 clinical trials (2 in adolescent and adult patients with seasonal allergic rhinitis and 1 in children with seasonal allergic rhinitis) demonstrated that Ryaltris improved nasal and eye symptoms in people with seasonal allergic rhinitis compared to placebo. However, compared to mometasone nasal spray, the improvements were not clinically meaningful in adolescents and adults, and there was no comparative evidence available in children. • The indirect evidence evaluated the comparative efficacy of Ryaltris versus intranasal corticosteroids and oral antihistamines in adolescent and adult patients, and versus intranasal corticosteroids in children. There were limitations in the indirect evidence that precluded meaningful conclusions on the efficacy of Ryaltris relative to active comparators in adolescent and adult patients or in children with seasonal allergic rhinitis. • Patients identified a need for new treatments that control the symptoms of seasonal allergic rhinitis and improve their quality of life. However, based on the evidence reviewed during the initial meeting and the reconsideration meeting, the Canadian Drug Expert Committee (CDEC) could not determine whether Ryaltris would address the unmet needs of patients because of the uncertainty around the benefit of Ryaltris versus appropriate active comparators.

We compared the antihistamine effect of four new antihistamines with olopatadine, which is used to treat equine allergic diseases. Six healthy Thoroughbred horses received oral doses of olopatadine (50 mg), levocetirizine (50 mg), bilastine (200 mg), rupatadine (100 mg), and desloratadine (50 mg) at >2-week intervals. The effects were investigated by measurement of the wheal area induced by histamine intradermal injection, and inhibition rate was compared with positive and negative controls. The maximum wheal inhibition rate (mean ± SD) of olopatadine (85.3% ± 7.7%) was significantly higher than those of bilastine (51.1% ± 11.8%), rupatadine (55.3% ± 6.6%), and desloratadine (59.8% ± 6.4%), but not levocetirizine (85.4% ± 8.0%). Levocetirizine is expected to have a high antihistamine effect on horses.

Analysis of structure-kinetic relationships (SKR) can contribute to an improved understanding of receptor-ligand interactions. Here, fragment 1 (4-(2-benzylphenoxy)-1-methylpiperidine) was used in different fragment growing approaches to mimic the putative binding mode of the long residence time (RT) ligands olopatadine, acrivastine, and levocetirizine at the histamine H1 receptor (H1R). SKR analyses reveal that introduction of a carboxylic acid moiety can increase RT at H1R up to 11-fold. Ligand efficiency (LE) decreases upon the introduction of the negatively charged group, whereas kinetic efficiency (KE) increases up to 8.5-fold. The olopatadine/acrivastine mimics give up to 15-fold differences in the RT, while the levocetirizine mimics afford similar RTs with only a 3-fold difference. Therefore, the levocetirizine mimics are less sensitive to structural changes. This study illustrates that for H1R, there are several ways to increase RT but the different strategies differ significantly in SKR.