A non-extraction sequential injection method for determination of loratadine using formation of its ion-association complex with bromocresol purple in acetonitrile

The formation of an ion-association complex (IA) between sulfonephthalein dye and basic nitrogen-containing compound in an organic solvent medium has been for the first time used to develop an automated SIA method. In highly polar aprotic solvents, the tautomeric equilibrium for such dyes is strongly shifted towards the colorless lactonic form. The addition of a basic nitrogen-containing substance leads to the formation of IA with a highly colored quinonoid form, which is accompanied by an increase in the absorbance of the dye band at approximately 400 nm. Protonation of pyridine nitrogen in loratadine, structure and binding places of IA were shown using quantum-chemical calculations. The very simple, direct and non-extraction spectrophotometric SIA method with high throughput of 43 h-1 was developed based on the formation of IA between loratadine and bromocresol purple in the medium of acetonitrile used both as solvent and carrier. The calibration graph was linear in the concentration range from 1.0 to 20 mg L-1 with correlation coefficient of 0.9992. The developed method was successfully applied to the analysis of pharmaceutical formulations.

Incorporation of Loratadine-Cyclodextrin Complexes in Oral Thin Films for Rapid Drug Delivery

Rapidly dissolving polymer thin films, or oral thin films (OTFs), have recently emerged as an improved oral drug delivery vehicle with its ability to bypass liver first pass metabolism, longer shelf-life, and simpler transport and distribution requirements, compared to traditional tablets and liquid formulations. Loratadine (LOR), an antihistamine commonly used to treat allergic rhinitis, undergoes liver first pass metabolism and is a prime candidate for incorporation within an OTF. However, loratadine is a BCS II drug with low aqueous solubility. Herein, the solubility of loratadine was improved by complexation with methyl β-cyclodextrin (MBCD) by co-evaporation of 2:1, 1:1, and 1:2 LOR:MBCD ratios and incorporation into a pullulan-based OTF at 4 wt% by solvent casting at 50 °C for 30 - 35 min. A therapeutically relevant 10 mg LOR dose could be prepared in a 3 cm by 3 cm OTF. The feasibility of complexation was observed with a Bs-type phase solubility diagram, and complexation itself was confirmed via differential scanning calorimetry (DSC) by disappearance of the LOR melting peak, Fourier-transform infrared spectroscopy (FTIR) by shifting of the C=O peak, via 1H NMR spectroscopy by downfield shifting and change in peak multiplicity of the LOR aromatic protons, and via diffusion-ordered spectroscopy by a decrease in the diffusion coefficient of LOR:MBCD complex. LOR:MBCD could be incorporated homogeneously throughout an OTF, and LOR:MBCD OTFs exhibited reasonable mechanical strength and endured 12 ± 3 folds before breaking. LOR:MBCD OTFs disintegrated within 38 ± 10 s. The cumulative in vitro release of LOR:MBCD OTFs peaked at 80 % within 3-4 min of dissolution, and LOR in LOR:MBCD OTFs exhibited permeability across a 0.22 μm nitrocellulose membrane, demonstrating its applicability as a rapid drug delivery vehicle.

Application of 32 factorial design for loratadine-loaded nanosponge in topical gel formulation: comprehensive in-vitro and ex vivo evaluations

Loratadine (LoR) is a highly lipophilic and practically insoluble in water, hence having a low oral bioavailability. As it is formulated as topical gel, it competitively binds with the receptors, thus reducing the side-effects. The objective of this study was to prepare LoR loaded nanosponge (LoR-NS) in gel for topical delivery. Nine different formulations of emulsion were prepared by solvent evaporation method with polyvinyl alcohol (PVA), ethyl cellulose (EC), and dichloromethane (DCM). Based on 32 Full Factorial Design (FFD), optimization was carried out by varying the concentration of LOR:EC ratio and stirring rate. The preparations were subjected for the evaluation of particle size (PS), in vitro release, zeta potential (ZP) and entrapment efficiency (EE). The results revealed that the NS dispersion was nanosized with sustained release profiles and significant PS. The optimised formulation was formulated and incorporated into carbopol 934P hydrogel. The formulation was then examined to surface morphological characterizations using scanning electron microscopy (SEM) which depicted spherical NS. Stability studies, undertaken for 2 months at 40 ± 2 °C/75 ± 5% RH, concluded to the stability of the formulation. The formulation did not cause skin irritation. Therefore, the prepared NS hydrogel proved to be a promising applicant for LoR as a novel drug delivery system (NDDS) for safe, sustained and controlled topical application.

Nanostructured Lipid Carrier-loaded In situ Gel for Ophthalmic Drug Delivery: Preparation and In vitro Characterization Studies

BACKGROUND

Nanostructured lipid carriers (NLCs) are explored as vehicles for ophthalmic drug delivery owing to their better drug loading, good permeation, and satisfactory safety profile.

OBJECTIVE

The purpose of the study was to fabricate and characterize an in situ ocular gel of loratadine as a model drug based on NLCs to enhance the drug residence time.

METHODS

NLCs were fabricated using the microemulsion method in which solid lipid as Compritol 888 ATO, lipid as oleic acid, surfactant as Tween 80, and isopropyl co-surfactant as alcohol, were used. Based on the evaluation of formulation batches of NLCs, the optimized batch was selected and further utilized for the formulation of in situ gel containing Carbopol 934 and HPMC K15M as gelling agents, and characterized.

RESULTS

The optimized NLCs of loratadine exhibited entrapment efficiency of 83.13 ± 0.13 % and an average particle size of 18.98 ± 1.22 nm. Drug content and drug release were found to be 98.67 and 92.48 %, respectively. Excellent rheology and mucoadhesion were demonstrated by the loratadine NLC-loaded in situ gel to enhance its attachment to the mucosa. NLC-based in situ ocular gel showed the desired results for topical administration. The prepared gel was observed to be non-irritating to the eye.

CONCLUSION

The optimized NLC-based in situ gel formulation presented better corneal retention and it was found to be stable, offering sustained release of the drug. Thus, the joined system of sol-gel was found promising for ophthalmic drug delivery.

Loratidine is associated with improved prognosis and exerts antineoplastic effects via apoptotic and pyroptotic crosstalk in lung cancer

BACKGROUND

Tumor-associated inflammation suggests that anti-inflammatory medication could be beneficial in cancer therapy. Loratadine, an antihistamine, has demonstrated improved survival in certain cancers. However, the anticancer mechanisms of loratadine in lung cancer remain unclear.

OBJECTIVE

This study investigates the anticancer mechanisms of loratadine in lung cancer.

METHODS

A retrospective cohort of 4,522 lung cancer patients from 2006 to 2018 was analyzed to identify noncancer drug exposures associated with prognosis. Cellular experiments, animal models, and RNA-seq data analysis were employed to validate the findings and explore the antitumor effects of loratadine.

RESULTS

This retrospective study revealed a positive association between loratadine administration and ameliorated survival outcomes in lung cancer patients, exhibiting dose dependency. Rigorous in vitro and in vivo assays demonstrated that apoptosis induction and epithelial-mesenchymal transition (EMT) reduction were stimulated by moderate loratadine concentrations, whereas pyroptosis was triggered by elevated dosages. Intriguingly, loratadine was found to augment PPARγ levels, which acted as a gasdermin D transcription promoter and caspase-8 activation enhancer. Consequently, loratadine might incite a sophisticated interplay between apoptosis and pyroptosis, facilitated by the pivotal role of caspase-8.

CONCLUSION

Loratadine use is linked to enhanced survival in lung cancer patients, potentially due to its role in modulating the interplay between apoptosis and pyroptosis via caspase-8.

Amelioration of acetic acid-induced ulcerative colitis in rats by cetirizine and loratadine via regulation of the PI3K/Akt/Nrf2 signalling pathway and pro-inflammatory cytokine release

Objectives

Ulcerative colitis is a chronic inflammatory bowel disease (IBD) that causes inflammation and ulcers in the rectum and the innermost layer of the large intestine. Our study aimed to elucidate the ameliorative effect of cetirizine (CTZ) and loratadine (LOR) against acetic acid-induced ulcerative colitis in rats via assessment of the PI3K/p-Akt/Nrf2 signaling pathway and proinflammatory cytokine release.

Materials and Methods

Thirty-two rats were allocated into four groups (n=8). Group (I) was considered normal control. Acetic acid (AA) was injected intrarectally in groups (2-4). Group (2) was kept untreated. Group (3) was administered CTZ (20 mg/kg/day) for 7 days. Group (4) was administered LOR (10 mg/kg/day) for 7 days.

Results

AA showed severe macroscopic colonic lesions associated with increased ulcer number, area, and severity with significantly elevated PI3K, p-Akt, Nrf2, TNF-α, and IL-6 in colorectal tissue as compared to the normal control group. All the aforementioned indicators were greatly improved by CTZ and LOR therapy.

Conclusion

This is the first study to elucidate the ameliorative effect of CTZ and LOR against AA-induced UC in rats. CTZ and LOR treatment mitigates UC via amelioration of the PI3K/p-Akt/Nrf2 pathway and proinflammatory cytokine release.

Simultaneous Determination of Montelukast Sodium and Loratadine by Eco-Friendly Densitometry and Spectrophotometric Methods

Recently, the aim of analytical community is to reduce the usage of hazardous chemicals; so eco-friendly, rapid, selective and cost-effective methods were developed for simultaneous determination of montelukast sodium (MKT) and loratadine (LRT). The first method was based on chromatographic separation performed on precoated silica gel 60 GF254 plates with ethyl acetate-ethanol 9: 1 (v/v) as the mobile phase. The developed plates were scanned and quantified at 260 nm. The method gives linear correlation over concentration ranges of 0.3-3.6 μg/spot and 0.2-4.0 μg/spot for MKT and LRT, respectively. It was also successfully applied to analysis of both drugs in their pharmaceutical preparation and human plasma. The other methods are UV-spectrophotometric methods based on smart spectra manipulating to zero order spectrum of each drug. These methods are named response correlation (RC), a-centering and ratio derivative methods. RC and a-centering methods were dependent on the presence of an isosbestic point between the overlapped spectra of both drugs. While ratio derivative method based on manipulation of the ratio spectra of both drugs. The two drugs obey Beer-Lambert law over the concentration ranges of 3.0-30.0 μg/mL in the three spectrophotometric methods. Moreover, the greenness of the developed methods is assessed using suitable analytical Eco-Scale and Green Analytical Procedure Index.

Loratadine oral bioavailability enhancement via solid dispersion loaded oro-dispersible films: Formulation, characterization and pharmacokinetics

Loratadine (LRD) belongs to second-generation tricyclic H1 antihistamine class, known for its non-sedating properties in allergic reactions. H1 antihistamines avoid and block the responses to allergens or histamine in nose and conjunctivae, thereby abolishing itching, congestion and sneezing. LRD is a Biopharmaceutical Class System (BCS) class II drug with dissolution or solubility limited absorption which limited the oral bioavailability and therapeutic efficacy of LRD. To improve the oral bioavailability of LRD for allergic disease (urticaria) treatment, LRD solid dispersions (LRD-SDs) were integrating into oro-dispersible films (ODFs). LRD-SDs were prepared through hot-melt extrusion method (HME) using d-alpha-tocopherol polyethylene glycol 1000 succinate (TPGS-1000), and polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer (SP). Subsequently, LRD-SDs were incorporated in ODFs by solvent casting method. The physicochemical and mechanical properties of LRD solid dispersions-loaded oro-dispersible films (LRD-SDs-ODFs), were evaluated. The in-vitro dissolution, ex-vivo permeation, oral bioavailability, and pharmacodynamics studies were conducted to evaluate LRD-SDs-ODFs efficiency. LRD-SDs-ODFs showed superior solubility and in-vitro dissolution results compared to that of pure LRD (p < 0.05). The solubility of the LRD-SD coded as LTS-4 was 190 times higher than the pure drug in aqueous media. The average hydrodynamic particle size (PS), polydispersity index (PDI), and zeta potential (ZP) of SD particles were 76 ± 2.1 nm, 0.20 ± 0.08 and - 19.16 ± 1.4 mV, respectively. Moreover, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) results confirmed the amorphousness of LRD in LRD-SDs-ODFs. The permeability flux of LRD was 44.6 ± 3.1 μg/cm2/h from DPF-5 formulation. Likewise, in vivo oral bioavailability of DPF-5 in Sprague-Dawley rats was significantly increased (p < 0.05) compared to free LRD. Further, wheal area was reduced 20 % higher than LRD in 8 h (p < 0.05). Overall, LRD-SDs-ODFs considerably enhanced LRD solubility, dissolution rate, bioavailability, and antihistaminic efficacy. Our findings show that SDs-ODFs is an effective carrier system for delivering poorly soluble LRD.

Computational modeling (in silico) methods combined with ecotoxicological experiments (in vivo) to predict the environmental risks of an antihistamine drug (loratadine)

This study employed computational modeling (in silico) methods, combined with ecotoxicological experiments (in vivo) to predict the persistence/biodegradability, bioaccumulation, mobility, and ecological risks of an antihistamine drug (Loratadine: LOR) in the aquatic compartment. To achieve these goals, four endpoints of the LOR were obtained from different open-source computational tools, namely: (i) "STP total removal"; (ii) Predicted ready biodegradability; (iii) Octanol-water partition coefficient (KOW); and (iv) Soil organic adsorption coefficient (KOC). Moreover, acute and chronic, ecotoxicological assays using non-target freshwater organisms of different trophic levels (namely, algae Pseudokirchneriella subcapitata; microcrustaceans Daphnia similis and Ceriodaphnia dubia; and fish Danio rerio), were used to predict the ecological risks of LOR. The main results showed that LOR: (i) is considered persistent (after a weight-of-evidence assessment) and highly resistant to biodegradation; (ii) is hydrophobic (LOG KOW = 5.20), immobile (LOG KOC = 5.63), and thus, it can potentially bioaccumulate and/or can cause numerous deleterious effects in aquatic species; and (iii) after ecotoxicological evaluation is considered "toxic" and/or "highly toxic" to the three trophic levels tested. Moreover, both the ecotoxicological assays and risk assessment (RQ), showed that LOR is more harmful for the crustaceans (RQcrustaceans = moderate to high risks) than for algae and fish. Ultimately, this study reinforces the ecological concern due to the indiscriminate disposal of this antihistamine drug in worldwide aquatic ecosystems.

Real-world practice of the Egyptian Kelleni's protocol amid changing tropism of SARS-CoV-2 omicron BA.5.2.1.7, XBB 1.5 and CH.1.1 subvariants: a multi-purpose protocol

The Egyptian immune-modulatory Kelleni's protocol, including nitazoxanide as an integral component, is being safely and effectively practiced to manage SARS-CoV-2, RSV, influenza infections in pediatric, adult and pregnant patients with negligible requirements for the relatively expensive diagnostic molecular tests. Most recently, Kelleni's protocol is being likewise used to manage potential norovirus infection which is currently confused with SARS-CoV-2 Omicron new enterotropic subvariants and the antihistaminic loratadine has been co-administered in selected patients. Notably, Africa has the least mandates, restrictions and SARS-CoV-2 vaccination rates and yet the least COVID-19 mortality.

Loratadine, an antihistaminic drug, suppresses the proliferation of endometrial stromal cells by inhibition of TRPV2

The transient receptor potential (TRP) channel TRPV2 is widely expressed in a variety of different cell types and tissues. However, elucidating the exact biological functions of TRPV2 is significantly hampered by the lack of selective pharmacological tools to modulate channel activity in vitro and in vivo. This study aimed to identify new compounds that modify TRPV2 activity via the use of a plate-based calcium imaging approach to screen a drug repurposing library. Three antihistaminic drugs, loratadine, astemizole and clemizole were identified to reduce calcium-influx evoked by the TRPV2 agonist tetrahydrocannabivarin in HEK293 cells expressing murine TRPV2. Using single-cell calcium-microfluorimetry and whole-cell patch clamp recordings, we further confirmed that all three compounds induced a concentration-dependent block of TRPV2-mediated Ca²⁺ influx and whole-cell currents, with loratadine being the most potent antagonist of TRPV2. Moreover, this study demonstrated that loratadine was able to block both the human and mouse TRPV2 orthologs, without inhibiting the activity of other closely related members of the TRPV superfamily. Finally, loratadine inhibited TRPV2-dependent responses in a primary culture of mouse endometrial stromal cells and attenuated cell proliferation and migration in in vitro cell proliferation and wound healing assays. Taken together, our study revealed that the antihistaminic drugs loratadine, astemizole and clemizole target TRPV2 in a concentration-dependent manner. The identification of these antihistaminic drugs as blockers of TRPV2 may form a new starting point for the synthesis of more potent and selective TRPV2 antagonists, which could further lead to the unravelling of the physiological role of the channel.

Evaluation of biotransformation capacity of transplastomic plants and hairy roots of Nicotiana tabacum expressing human cytochrome P450 2D6

Cytochrome P450 monooxygenases (CYPs) are important tools for regio- and stereoselective oxidation of target molecules or engineering of metabolic pathways. Functional heterologous expression of eukaryotic CYPs is often problematic due to their dependency on the specific redox partner and the necessity of correct association with the membranes for displaying enzymatic activity. Plant hosts offer advantages of accessibility of reducing partners and a choice of membranes to insert heterologous CYPs. For the evaluation of plant systems for efficient CYP expression, we established transplastomic plants and hairy root cultures of Nicotiana tabacum carrying the gene encoding human CYP2D6 with broad substrate specificity. The levels of CYP2D6 transcript accumulation and enzymatic activity were estimated and compared with the data of CYP2D6 transient expression in N. benthamiana. The relative level of CYP2D6 transcripts in transplastomic plants was 2-3 orders of magnitude higher of that observed after constitutive or transient expression from the nucleus. CYP2D6 expressed in chloroplasts converted exogenous synthetic substrate loratadine without the need for co-expression of the cognate CYP reductase. The loratadine conversion rate in transplastomic plants was comparable to that in N. benthamiana plants transiently expressing a chloroplast targeted CYP2D6 from the nucleus, but was lower than the value reported for transiently expressed CYP2D6 with the native endoplasmic reticulum signal-anchor sequence. Hairy roots showed the lowest substrate conversion rate, but demonstrated the ability to release the product into the culture medium. The obtained results illustrate the potential of plant-based expression systems for exploiting the enzymatic activities of eukaryotic CYPs with broad substrate specificities.

Loratadine

Loratadine, 4-(8-Chloro-5,6-dihydro-11H-benzo[5,6]cyclohepta[1,2-b]pyridin-11-ylidene)-1-piperidinecarboxylic acid ethyl ester, is an antihistamine drug with long-acting effects and has limited selectivity for peripheral H1 receptors. It is widely used for the prevention of allergic diseases such as rhinitis chronic urticaria, and asthma. This chapter discusses, by a critical extensive review of the literature, the description of loratadine in terms of its names, formulae, elemental composition, appearance, methods of preparation. The profile contains physicochemical properties of Loratadine, including pKa value, solubility and X-ray powder diffraction. In addition, it involves Fourier transform infrared spectrometry, nuclear magnetic resonance spectroscopy and mass spectroscopy for functional groups and structural confirmation of. The chapter also includes methods of analysis of the drug such as compendial, titrimetric, electrochemical, spectroscopic, chromatographic and capillary electrophoretic methods. The chapter also covers clinical applications of the drug such as its uses, doses, ADME profiles and mechanism of action.

Ultrasensitive TLC determination of montlukast and loratadine mixture in human plasma utilizing fluorescence detection at dual pH values: Toward attaining separate maximum fluorescence intensity

A novel selective and highly sensitive TLC densitometric method with reflectance/fluorescence detection was developed to separate and quantify montlukast (MONT) and loratadine (LOR). Separation of the studied drugs was performed on precoated silica gel TLC plates using chloroform-ethyl acetate (8 :2 v/v) as a mobile phase. MONT quantification was carried out by measuring emission using 400 nm optical filter after excitation at 340 nm. Enhancement of the week LOR fluorescence was performed through adequate spraying the chromatograms with 0.2 M perchloric acid leading to enhancing sensitivity by 17 folds compared to the reported HPTLC methods with absorbance detection. The scanner was set at 275 nm excitation wavelength and 400 nm optical filter. Detection of both drugs on the same plate separately at different pH conditions was utilized for the first time. Maximum fluorescence was achieved for each of them and this enhances detection sensitivity for both drugs. The linear regression analysis data of the studied drugs produced a good linear relationship with correlation coefficients of 0.996 for MONT and 0.998 for LOR over the concentration range of 6 - 150 ng/band for MONT and 15 - 120 ng/band for LOR. Limit of detection values were 1.7 and 4.5 ng /band for MONT and LOR respectively. The developed method enabled the detection of MONT and LOR in human plasma samples within linear concentrations ranged from 7 to 140 ng/ band and 16 to 50 ng/ band with detection limits of 1.9 and 4.8 ng/band for MONT and LOR respectively. The analytical performance of the proposed method was evaluated according to the International Council for Harmonization (ICH). The method was successfully applied for the analysis of the studied drugs in spiked human plasma and good recovery percentages were obtained indicating that there is no interference from plasma constituents. Therefore the method can be applied for in vivo analysis and pharmacokinetic study.

A novel nasal co-loaded loratadine and sulpiride nanoemulsion with improved downregulation of TNF-α, TGF-β and IL-1 in rabbit models of ovalbumin-induced allergic rhinitis

PURPOSE

The work aimed to develop a co-loaded loratadine and sulpiride nasal nanoemulsion for allergic rhinitis management.

METHODS

Compatibility studies were conducted adopting differential scanning calorimetry and Fourier transform infrared spectroscopy. Nanoemulsion formulations were prepared using soybean lecithin, olive oil and tween 80. Sodium cholate and glycerol were employed as co-surfactants. Nanoemulsions were assessed for viscosity, pH, droplet size, polydispersity index, zeta potential, electrical conductivity, entrapment, In vitro drug release and corresponding kinetics. Stability of the selected formulation was investigated. The biological effectiveness was evaluated in rabbit models of ovalbumin-induced allergic rhinitis by measuring TNF-α, TGF-β and IL-1.

RESULTS

Compatibility studies revealed absence of drug/drug interactions. Nanoemulsions exhibited > 90% entrapment efficiency. The selected nanoemulsion demonstrated small droplet size (85.2 ± 0.2 nm), low PDI (0.35 ± 0.0) and appropriate Zeta Potential (-23.3 ± 0.2) and stability. It also displayed enhanced in vitro drug release following the Higuashi Diffusion and Baker-Lonsdale models. The mean relative mRNA expression of TNF-α, IL-1 and TGF-β significantly decreased from 9.59 ± 1.06, 4.15 ± 0.02 and 4.15 ± 0.02 to 1.28 ± 0.02, 1.93 ± 0.06 and 1.56 ± 0.02 respectively after treatment with the selected nanoemulsion formulation.

CONCLUSION

The results reflected a promising potent effect of the combined loratadine and sulpiride nasal nanoemulsion in managing the symptoms of allergic rhinitis.

Testing of the inhibitory effects of loratadine and desloratadine on SARS-CoV-2 spike pseudotyped virus viropexis

Currently, there is an urgent need to find a treatment for the highly infectious coronavirus disease (COVID-19). However, the development of a new, effective, and safe vaccine or drug often requires years and poses great risks. At this critical stage, there is an advantage in using existing clinically approved drugs to treat COVID-19. In this study, in vitro severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) spike pseudotyped viral infection experiments indicated that histamine H₁ antagonists loratadine (LOR) and desloratadine (DES) could prevent entry of the pseudotyped virus into ACE2-overexpressing HEK293T cells and showed that DES was more effective. Further binding experiments using cell membrane chromatography and surface plasmon resonance demonstrated that both antagonists could bind to ACE2 and that the binding affinity of DES was much stronger than that of LOR. Molecular docking results elucidated that LOR and DES could bind to ACE2 on the interface of the SARS-CoV-2-binding area. Additionally, DES could form one hydrogen bond with LYS31 but LOR binding relied on non-hydrogen bonds. To our knowledge, this study is the first to demonstrate the inhibitory effect of LOR and DES on SARS-CoV-2 spike pseudotyped virus viropexis by blocking spike protein-ACE2 interaction. This study may provide a new strategy for finding an effective therapeutic option for COVID-19.

Experimental study on the reduction of loratadine particle size through confined liquid impinging jets

The confined liquid impinging jets (CLIJ) technique was applied as a simple and effective approach to reducing the particle size of loratadine to enhance its solubility. The effect of anti-solvent (AS) to solution (S) flow rate ratio, organic phase concentration, Reynolds number (Re), and stabilizer concentration was investigated in this reduction process. After the synthesis, the chemical and physical properties of loratadine nanoparticles were determined through different characterization and analytical techniques. The results indicated that the particle size of loratadine decreases from 320 nm to 80 nm by increasing the AS/S ratio from 1 to 25. It was found that the particle size of loratadine was unchanged at the higher AS/S ratios. The loratadine nanoparticle size was optimized by changing the solution concentration, Re, and Tween 80 as a stabilizer. The finest loratadine nanoparticle size of about 53 nm was obtained with a narrow size distribution, which corresponds to solution concentration of 35 mg/mL, Re of 5687, and 0.1% (w/v) stabilizer concentration. It was revealed that the optimized loratadine nanoparticles completely dissolved after 11 min, indicating the loratadine nanoparticle dissolution rate 50 times faster than raw loratadine.

Ginger extract versus Loratadine in the treatment of allergic rhinitis: a randomized controlled trial

BACKGROUND

Allergic rhinitis (AR) is a non-infectious immune disease and incidents of the disease has continuously increased in Thailand. Ginger, a Thai herb, is used in food and Thai traditional medicine. This study was designed to assess efficacy and safety of ginger extract in comparison with loratadine for AR treatment.

METHODS

AR patients were treated with ginger extract 500 mg (n = 40) against those treated with loratadine 10 mg (n = 40) in a randomized, double-blind, controlled trial for 3 and 6 weeks. The efficacy was evaluated from clinical examinations i.e. total nasal symptom scores (TNSS), cross-sectional area of the nasal cavity with acoustic rhinometry (ARM) and rhinoconjunctivitis quality of life questionnaire (RQLQ). The safety of treatment was measured by blood pressure, blood analysis and history-taking for side effects.

RESULTS

The results showed both ginger extract and loratadine treated groups significantly decreased TNSS scores but there was no significant difference between the two groups. In acoustic rhinometry measurement, the ginger treated group significantly gradually increased the estimated volume of the nasal cavity and decreased distances from the nostril, but the loratadine treated group did not cause a change. Both groups gave significantly improvement in every aspect of the RQLQ at third weeks. The treatment with ginger extract was as safe as loratadine as shown by renal and liver function results obtained from blood analysis. Both treatments had no effect on blood pressure of the patients.

CONCLUSIONS

The ginger extract is as good as loratadine in improving nasal symptoms and quality of life in AR patients. However, ginger extract caused less side effects especially, drowsiness, fatigue, dizziness and constipation. Therefore, the ginger extract could be used as alternative treatment for patients with AR.

TRIAL REGISTRATION

Registered with ClinicalTrials.gov (Registration number: NCT02576808) on 15 October 2015.

Loratadine, an antihistamine drug, exhibits anti-inflammatory activity through suppression of the NF-kB pathway

Loratadine is an antihistamine drug that shows promise as an anti-inflammatory drug, but supportive studies are lacking. We elucidated the effects and mechanisms by which loratadine inhibits inflammatory responses. Molecular components were evaluated in macrophages by nitric oxide assay, polymerase chain reaction, luciferase assay, immunoblotting, overexpression strategies and cellular thermal shift assay. At the molecular level, loratadine reduced the levels of nitric oxide, iNOS, IL-1β, TNF-α, IL-6, and COX-2 in RAW264.7 cells treated with lipopolysaccharide. Loratadine also specifically inhibited the NF-_kB pathway, targeting the Syk and Src proteins. Furthermore, loratadine bound Src in the bridge between SH2 and SH3, and bound Syk in the protein tyrosine kinase domain. The NF-_kB signaling pathway was assessed along with putative binding sites through a docking approach. The anti-inflammatory effect of loratadine was tested using mouse models of gastritis, hepatitis, colitis, and peritonitis. Stomach tissue histopathology, liver morphology, and colon length in the loratadine group were improved over the group without loratadine treatment. Taken together, loratadine inhibited the inflammatory response through the NF-_kB pathway by binding with the Syk and Src proteins.

Nasal delivery of nanosuspension-based mucoadhesive formulation with improved bioavailability of loratadine: Preparation, characterization, and in vivo evaluation

The unique requirements of poorly water-soluble drug delivery have driven a great deal of research into new formulations and routes of administration. This study investigates the use of nanosuspensions for solubility enhancement and drug delivery. Simple methods were used to prepare nasal formulations of loratadine based on nanosuspension pre-dispersion with sodium hyaluronate as a mucoadhesive agent. The nanosuspension was prepared by antisolvent precipitation method followed by ultrasonication and characterized for particle size, polydispersity index, zeta potential, morphology, and structure. Moreover, the nasal formulations were characterized for drug loading, pH, particle size, viscosity, bioadhesive viscosity parameter, and were evaluated for in vitro dissolution and diffusion, in addition to in vivo studies in a rat model. Loratadine nanosuspension displayed a particle size of 311 nm, a polydispersity index of 0.16, and zeta potential of -22.05 mV. The nanosuspension preserved the crystalline status of the raw drug. The addition of sodium hyaluronate exhibited an increase in the mean particle size and zeta potential of the nanoparticles. The nasal formulations showed enhanced bioadhesive properties compared to the unprocessed loratadine in the reference samples. The nanosuspension based-formulation that contained 5 mg mL^-1 sodium hyaluronate and 2.5 mg mL^-1 loratadine (NF4) showed a significant enhancement of flux and permeability coefficient through a synthetic membrane. NF4 exhibited 24.73 µg cm^-2 h^-1 and 0.082 cm h^-1, while the reference sample showed 1.49 µg cm^-2 h^-1 and 0.017 cm h^-1, for the flux and the permeability coefficient, respectively. Nasal administration of NF4 showed a bioavailability of 5.54-fold relative to the oral administration. The results obtained in this study indicate the potential of the nasal route and the nanosuspension for loratadine delivery. The relative bioavailability of NF4 was 1.84-fold compared to unprocessed loratadine in the reference sample. Therefore, the nanosized loratadine could be suggested as a practical and simple nanosystem for the intranasal delivery with improved bioavailability.

Oral loratadine in the management of G-CSF-induced bone pain: a pilot study

This pilot study aimed to ascertain if bone pain induced by granulocyte-colony stimulating factors (G-CSFs) can be alleviated or eliminated by oral antihistamine loratadine. Twelve patients with cancer receiving chemotherapy were included in the study. Daily pain increased between before treatment started and after cycle 1 in all patients. All 12 participants were started on loratadine on cycle 2; three patients were taking pain medications in addition to this as needed, which were ibruprofen (n=1) or tramadol (n=2). Pain decreased towards the later cycles after patients were started on loratadine in cycle 2, with the exception of one patient who also took tramadol as needed in cycle 3. Oral loratadine was found to be associated with pain reduction in patients with cancer receiving G-CSFs.

A simple and low-energy method to prepare loratadine nanosuspensions for oral bioavailability improvement: preparation, characterization, and in vivo evaluation

The effervescent method, as a simple and effective technology to prepare nanosuspensions, has gained great attention. In this present research, loratadine (LTD) nanosuspensions were successfully prepared by the effervescent method using Soluplus as stabilizer to improve the bioavailability of LTD in vivo. The mean particle size was about 100 nm. And the LTD nanosuspensions were lyophilized for further study. The freeze-dried powders could be dissolved quickly, and the mean particle size remained almost unchanged after powders were re-dissolved. By transmission electron microscope (TEM), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, and X-ray diffraction (X-RD), the characterizations of LTD nanosuspensions and freeze-dried powders were studied. Commercial tablets were used as the reference to investigate the dissolution behaviors in different release media and of bioavailability in vivo of LTD freeze-dried powders. The cumulative dissolution of the LTD freeze-dried powders was superior in different release media compared with commercial tables. In addition, for the evaluation of the bioavailability of LTD nanosuspensions, the LTD concentration in rat plasma was determined using LC-MS/MS method. The results showed that the AUC_0-24 and C_max of LTD freeze-dried powders were about 2.14- and 2.01-fold higher than those of commercial tablets. In short, the effervescent method has been successfully applied to the preparation of LTD nanosuspensions to improve the bioavailability of LTD in vivo with the advantage of low energy consumption. This simple technology also provides an idea for the preparation of the other nanosuspensions.

Histamine Receptor Antagonists, Loratadine and Azelastine, Sensitize P-gp-overexpressing Antimitotic Drug-resistant KBV20C Cells Through Different Molecular Mechanisms

BACKGROUND/AIM

Previously, we showed that KBV20C cancer cells highly resistant to antimitotic drugs were sensitized by co-treatment with a repositioned drug fluphenazine.

MATERIALS AND METHODS

Considering that fluphenazine plays a role as a histamine receptor antagonist, we investigated low doses of 21 other histamine receptor antagonists (lidocaine, cimetidine, chlorpromazine, diphenhydramine, promethazine, ranitidine, famotidine, clemastine, chlorpheniramine, desloratadine, loratadine, cyproheptadine, azelastine, brompheniramine, carbinoxamine, fexofenadine, hydroxyzine, levocetirizine, meclizine, nizatidine, and pemirolast) to identify repositioned drugs for their sensitizing effects on antimitotic drug-resistant KBV20C cells at relatively low doses.

RESULTS

Co-treatment with loratadine, and with azelastine highly sensitized KBV20C cells to vincristine treatment. Loratadine and azelastine reduced cell viability, increased G₂ arrest, and up-regulated apoptosis when co-administered with vincristine. In detailed quantitative analysis, combination of vincristine with loratadine had a higher sensitization effect than that with azelastine. Azelastine had a higher P-glycoprotein (P-gp)-inhibitory activity, similar to that of verapamil, indicating that sensitization by vincristine-azelastine involved the P-gp-inhibitory effects of azelastine. However, loratadine had a very low P-gp-inhibitory activity, suggesting that loratadine sensitization to vincristine is independent of the P-gp-inhibition. Co-treatment with eribulin and loratadine increased the sensitization of KBV20C cells, suggesting that loratadine can be combined with other antimitotic drugs to sensitize resistant cancer cells.

CONCLUSION

These findings provide important information regarding the sensitization of drug-resistant cells and indicate that loratadine may be used in patients with potentially resistant cancer without any toxic effects from P-gp inhibition.

Loratadine self-microemulsifying drug delivery systems (SMEDDS) in combination with sulforaphane for the synergistic chemoprevention of pancreatic cancer

Pancreatic cancer (PC), currently the third leading cause of cancer-related deaths in the USA, is projected to become the second leading cause, behind lung cancer, by 2020. The increasing incidence, low survival rate, and limited treatment opportunities necessitate the use of alternative approaches such as chemoprevention, to tackle PC. In this study, we report significant synergistic chemoprevention efficacy for the first time from a low-dose combination of a classical antihistaminic drug, Loratadine (LOR) and a neutraceutical compound, Sulforaphane (SFN) using a self-microemulsifying drug delivery system (SMEDDS) formulation. The formulation was developed using Quality by Design approach (globule size, 95.13 ± 7.9 nm; PDI, 0.17 ± 0.04) and revealed significant (p < 0.05) enhancement in the in vitro dissolution profile confirming the enhanced solubility of BCS class II drug LOR with SMEDDS formulation. The LOR-SFN combination revealed ~ 40-fold reduction in IC50 concentration compared to LOR alone in MIA PaCa-2 and Panc-1 cell lines respectively, confirming the synergistic enhancement in chemoprevention. Further, the nanoformulation resulted in ~ 7-fold and ~ 11-fold reduction in IC50 values compared to LOR-SFN combination. Hence, our studies successfully demonstrate that a unique low-dose combination of LOR encapsulated within SMEDDs with SFN shows significantly enhanced chemopreventive efficacy of PC.

Ecotoxic effects of loratadine and its metabolic and light-induced derivatives

Loratadine and desloratadine are second-generation antihistaminic drugs. Because of human administration, they are continuously released via excreta into wastewater treatment plants and occur in surface waters as residues and transformation products (TPs). Loratadine and desloratadine residues have been found at very low concentrations (ng/L) in the aquatic environment but their toxic effects are still not well known. Both drugs are light-sensitive even under environmentally simulated conditions and some of the photoproducts have been isolated and characterized. The aim of the present study was to investigate the acute and chronic ecotoxicity of loratadine, desloratadine and their light-induced transformation products in organisms of the aquatic trophic chain. Bioassays were performed in the alga Pseudokirchneriella subcapitata, the rotifer Brachionus calyciflorus and in two crustaceans, Thamnocephalus platyurus and Ceriodaphnia dubia. Loratadine exerted its acute and chronic toxicity especially on Ceriodaphnia dubia (LC50: 600 µg/L, EC50: 28.14 µg/L) while desloratadine showed similar acute toxicity among the organisms tested and it was the most chronically effective compound in Ceriodaphnia dubia and Pseudokirchneriella subcapitata. Generally, transformation products were less active in both acute and chronic assays.

A Novel Surfactant-free Lipid-based Formulation for Improving Oral Bioavailability of Loratadine Using Colloidal Silicon Dioxide as Emulsifier and Solid Carrier

BACKGROUND

The purpose of this study was to develop an innovative surfactant-free lipidbased formulation (LF) for improving oral bioavailability of loratadine based on using solid particles colloidal silicon dioxide (CSD) as emulsifier and solid carrier.

METHODS

Loratadine was dissolved in oil solution with the aid of co-solvent and LF formulations were prepared by a simple adsorption and milling technique. The LF Powder was evaluated in terms of angle of repose and X-ray powder diffraction. After dispersing and emulsifying in water, the particle size and morphology were also characterized. In vitro dissolution and pharmacokinetic behavior in vivo were also studied.

RESULTS

Orthogonal design indicated that the amount of CSD in formulations had a major and significant influence on emulsification. The optimal formulation showed LF with good flowability and without crystallization or deposition of loratadine in it.

CONCLUSION

After dispersing in water, an emulsion with the mean droplet size of 1.2μm was obtained. Although the dissolution of drug from LF was slower in vitro in acidic aqueous solution, pharmacokinetic studies in vivo showed that the bioavailability of loratadine increased 2.49-fold by CF compared to a commercial tablet.

Onset of Action of the Fixed Combination Intranasal Azelastine-Fluticasone Propionate in an Allergen Exposure Chamber

BACKGROUND

A fixed-dose combination of intranasal azelastine hydrochloride and fluticasone propionate (MP-AzeFlu) is the most effective treatment of allergic rhinitis, but its onset of action requires further investigation.

OBJECTIVE

To compare the onset of action of MP-AzeFlu with the free combination of oral loratadine (LORA) and intranasal fluticasone propionate (INFP).

METHODS

In this single-center, randomized, placebo-controlled, double-blind, double-dummy, 3-period crossover trial, allergic rhinitis symptoms were induced in asymptomatic patients by ragweed pollen challenge in an allergen environmental exposure chamber. Patients received single-dose MP-AzeFlu, LORA/INFP, or placebo and were monitored for 4 hours. The primary outcome was onset of action measured by total nasal symptom score (TNSS). Secondary measures were total ocular symptom score (TOSS), total score of the 7 nasal and ocular symptoms (T7SS), and the global visual analog scale (VAS).

RESULTS

The full analysis set included 82 patients, of which 78 completed all treatments. TNSS was significantly reduced versus placebo from 5 minutes for MP-AzeFlu and 150 minutes for LORA/INFP onward (both P < .05) till the end of assessment (0-4 hours). MP-AzeFlu reduced TNSS to a greater extent at each time point from 5 to 90 minutes (P < .05) and over the entire assessment interval (P ≤ .005) versus LORA/INFP or placebo. No statistically significant difference between LORA/INFP and placebo was observed over the assessment interval (P = .182). The onset of action of MP-AzeFlu assessed by TOSS, T7SS, and VAS was 10 minutes, 2 hours earlier than with LORA/INFP.

CONCLUSION

MP-AzeFlu had a more rapid onset of action (5 minutes) and was more effective than LORA/INFP.

Onset of action for loratadine tablets for the symptomatic control of seasonal allergic rhinitis in adults challenged with ragweed pollen in the Environmental Exposure Unit: a post hoc analysis of total symptom score

Background

Loratadine is a second-generation, non-sedating antihistamine used for the relief of allergic rhinitis symptoms. Previous studies reported that when loratadine was encapsulated, the onset of action for symptom relief was 180 min. However, unmodified loratadine tablets were not evaluated at that time. Using data from a previously published Environmental Exposure Unit (EEU) study comparing azelastine nasal spray with loratadine tablets, cetirizine tablets, and placebo, this post hoc analysis determines the onset of action of loratadine tablets (i.e. unmodified) by analyzing the total symptom score for the relief of nasal and ocular seasonal allergic rhinitis (SAR) symptoms.

Methods

A Phase IV, randomized, single-center, double-blind, placebo-controlled, double-dummy, four-way crossover study was conducted in the EEU. Seventy participants were randomized sequentially into one of the four treatments during ragweed pollen exposure. Nasal and ocular symptom scores were self-reported by the participants and recorded. The original study analysis was carried out by evaluating the nasal symptom scores only. For this post hoc analysis, both nasal and ocular data from the loratadine and placebo treatment arms were analyzed. The primary endpoint for this analysis was the onset of action of loratadine as measured by the change in total symptom score (TSS) from baseline in comparison to placebo. The onset of ocular symptom relief using the total ocular symptom score (TOSS) was also reported.

Results

Loratadine tablets demonstrated a significant and durable improvement in both TSS (P = .005) and TOSS (P = .013) at 75 min post-treatment administration compared to placebo. The mean proportion of participants reporting none or mild for all component symptoms of TSS and TOSS at 75 min and thereafter was significantly higher in the loratadine (TSS, P = .0005; TOSS, P ≤ .0001) vs. placebo treatment arm.

Conclusions

The onset of action of loratadine tablets was 75 min for the relief of nasal and ocular symptoms in adults with SAR. These results suggest a faster onset of action for loratadine tablets (75 min) compared to previously reported studies which were conducted with modified (i.e. gelatin-encapsulated) loratadine tablets (180 min).

Trial registration Clinicaltrials.gov identifier NCT00561717

Electronic supplementary material

The online version of this article (10.1186/s13223-017-0227-4) contains supplementary material, which is available to authorized users.

Loratadine-Loaded Thermoresponsive Hydrogel: Characterization and Ex-vivo Rabbit Cornea Permeability Studies

Poor bioavailability of ophthalmic drops is mainly due to drainage through the nasal-lacrimal duct and a very low permeability through corneal epithelium. The aim of our study was to prepare and characterize an ocular hydrogel of loratadine, as an example of a lipophilic drug, to increase drug concentration and residence time at the site of action in the eye. In this study, a 2³ full factorial design was employed to design and compare the properties of eight different loratadine containing hydrogel formulations. Results showed a significant correlation between the swelling and porosity ratios of the hydrogels and the Pluronic percentage and Pluronic/carbomer ratio in the formulations. Moreover, the release profiles showed fast and sustained release of all the formulations. Evaluation of hydrogels structure by the FT-IR technique indicated that Pluronic interacts with hydroxyl and carboxylic groups in carbomer, which is the main reason of the hydrogel network formation and interacts with loratadine.The permeation of loratadine through rabbit cornea showed that drug permeation percentages for the F2 and F7 formulations were 15 and 70 folds more than that of the control.

Loratadine bioavailability via buccal transferosomal gel: formulation, statistical optimization, in vitro/in vivo characterization, and pharmacokinetics in human volunteers

Loratadine (LTD) is an antihistaminic drug that suffers limited solubility, poor oral bioavailability (owing to extensive first-pass metabolism), and highly variable oral absorption. This study was undertaken to develop and statistically optimize transfersomal gel for transbuccal delivery of LTD. Transfersomes bearing LTD were prepared by conventional thin film hydration method and optimized using sequential Quality-by-Design approach that involved Placket-Burman design for screening followed by constrained simplex-centroid design for optimization of a Tween-80/Span-60/Span-80 mixture. The transferosomes were characterized for entrapment efficiency, particle size, and shape. Optimized transferosomes were incorporated in a mucoadhesive gel. The gel was characterized for rheology, ex vivo permeation across chicken pouch buccal mucosa, in vitro release, and mucoadhesion. Pharmacokinetic behavior of LTD formulations was investigated in healthy volunteers following administration of a single 10-mg dose. Optimal transferosomes characterized by submicron size (380 nm), spherical shape and adequate loading capacity (60%) were obtained by using quasi-equal ratio surfactant mixture. In terms of amount permeated, percentage released, and mucoadhesion time, the transferosomal gel proved superior to control, transferosome-free gel. Bioavailability of the transferosomal gel was comparable to Claritin® oral tablets. However, inter-individual variability in C_max and AUC was reduced by 76 and 90%, respectively, when the buccal gel was used. Linear Correlation of in vitro release with in vivo buccal absorption fractions was established with excellent correlation coefficient (R²>0.97). In summary, a novel buccal delivery system for LTD was developed. However, further clinical investigation is warranted to evaluate its therapeutic effectiveness and utility.

NOLAN: a randomized, phase 2 study to estimate the effect of prophylactic naproxen or loratadine vs no prophylactic treatment on bone pain in patients with early-stage breast cancer receiving chemotherapy and pegfilgrastim

Purpose

Mild-to-moderate bone pain is a commonly reported adverse event (AE) associated with pegfilgrastim. We evaluated the effect of prophylactic naproxen or loratadine vs no prophylactic treatment on pegfilgrastim-associated bone pain.

Methods

In this open-label study (NCT01712009), women ≥ 18 years of age with newly diagnosed stage I–III breast cancer and an ECOG performance status ≤ 2 who were planning ≥ 4 cycles of adjuvant or neoadjuvant chemotherapy with pegfilgrastim support starting in cycle 1 were randomized 1:1:1 to receive naproxen, loratadine, or no treatment to prevent pegfilgrastim-associated bone pain. The primary endpoint was all-grade bone pain in cycle 1 from AE reporting. Secondary endpoints included bone pain in cycles 2–4 and across all cycles from AE reporting and patient-reported bone pain by cycle and across all cycles.

Results

Six hundred patients were enrolled. Most patients (83.0%) were white, and mean (SD) age was 54.2 (11.1) years. The percentage of patients with all-grade bone pain in cycle 1 from AE reporting in the naproxen, loratadine, and no prophylaxis groups was 40.3, 42.5, and 46.6%, respectively; differences between the treatment groups were not statistically significant. Maximum, mean, and area under the curve for patient-reported bone pain were consistently lower in the naproxen and loratadine groups than in the no prophylaxis group; some of these differences were significant. Loratadine was associated with fewer treatment-related AEs and discontinuations than naproxen.

Conclusions

Given its tolerability, its ease of administration, and its potential benefit, treatment with loratadine should be considered to help prevent bone pain in patients receiving chemotherapy and pegfilgrastim.

Clinical trial registration

ClinicalTrials.gov; NCT01712009

Electronic supplementary material

The online version of this article (10.1007/s00520-017-3959-2) contains supplementary material, which is available to authorized users.

A cell-based assay using HepaRG cells for predicting drug-induced phospholipidosis

The utility of HepaRG cells as an in vitro cell-based assay system for predicting drug-induced phospholipidosis (PLD) was investigated. In experiment 1, 10 PLD-positive compounds and 11 PLD-negative compounds were selected. HepaRG cells were treated with each compound for 48 hr. In experiment 2, loratadine and desloratadine, a major metabolite of loratadine, were used to assess metabolic activation for PLD. HepaRG cells were treated with loratadine and desloratadine in the presence or absence of 500 μM 1-aminobenzotriazole (ABT), a broad CYP inhibitor, for 48 hr. After treatment with compounds in experiments 1 and 2, the relative fluorescence intensity (RFI) was measured using LYSO-ID Red dye to assess the PLD induction. In experiment 1, our cell-based assay system using HepaRG cells exhibited 100% sensitivity and 100% specificity for predicting drug-induced PLD. In experiment 2, loratadine increased the RFI in the PLD assay. However, the increase in the RFI was not observed in co-treatment with loratadine and ABT. In addition, desloratadine increased the RFI in the presence and absence of ABT. These results suggested that metabolic activation of loratadine may contribute to PLD in HepaRG cells. We newly demonstrated that HepaRG cells have a high ability for predicting drug-induced PLD. In addition, we newly showed that HepaRG cells may predict drug-induced PLD mediated by metabolic activation of loratadine. Thus, a cell-based assay system using HepaRG cells is a useful model for predicting drug-induced PLD.

Development, stability and in vitro delivery profile of new loratadine-loaded nanoparticles

Purpose: Loratadine is used as antihistaminic without side effects in nervous systems. This drug is a weak base and it is absorbed from the intestine. The nitrogen of the pyridine ring is protonated in the stomach affecting the oral bioavailability. The aim of this paper was obtaining, characterize and evaluate the release profiles and the stability of a gastroresistant loratadine nanosuspension. Methods: The nanosuspension was prepared by the solvent displacement evaporation method, using three different polymers (Eudragit® L 100 55, Kollicoat® MAE 100P and PEG 4000) and Polysorbate 80. Dynamic Light Scattering was used for evaluating the particle size (PS), zeta potential, and conductivity of the nanosuspension. Loratadine release profiles were evaluated in simulated gastrointestinal fluids. The shelf and accelerated stability were assessed during three months. Results: Nanosuspension particle size was 45.94 ± 0.50 nm, with a low polydispersion index (PdI, 0.300). Kollicoat® MAE 100P produced a hard and flexible coating layer. In simulated intestinal fluids, the 100 percent of loratadine was released in 40 min, while in simulated stomach fluids the release was lesser than 5%. Nanosuspension presented a good physicochemical stability showing a reduction in PS and PdI after three months (43.29 ± 0.16 and 0.250; respectively). Conclusions: A promissory loratadine nanosuspension for loratadine intestinal delivery was obtained, by using a low energy method, which is an advantage for a possible scale up for practical purpose.

Interaction of Approved Drugs with Synaptic Vesicle Protein 2A

Levetiracetam (LEV) and its recently approved derivative brivaracetam are anti-epileptic drugs with a unique mechanism of action. The synaptic vesicle protein 2A (SV2A) was previously identified as their main target. In the current study, we tested a collection of 500 approved drugs for interaction with the human SV2A protein expressed in Chinese hamster ovary cells. Competition binding studies were performed using cell lysates with high SV2A expression and [³ H]brivaracetam as a radioligand. A hit rate of 3% was obtained, defined as compounds that inhibited radioligand binding by more than 90% at a screening concentration of 20 μM. Subsequent concentration-inhibition curves revealed the antihistaminic prodrug loratadine (K_i  = 1.16 μM) and the antimalarial drug quinine (K_i  = 2.03 μM) to be the most potent SV2A protein ligands of the investigated drug library. Both compounds were similarly potent as LEV (K_i  = 1.74 μM), providing structurally novel scaffolds for SV2A ligands. A pharmacophore model was established, which indicated steric and electronic conformities of brivaracetam with the new SV2A ligands, and preliminary structure-activity relationships were determined. The anti-convulsive effects of the natural product quinine may - at least in part - be explained by interaction with SV2A. Loratadine and quinine represent new lead structures for anti-epileptic drug development.

Histamine induces NF-κB controlled cytokine secretion by orbital fibroblasts via histamine receptor type-1

Mast cells and their products are likely to be involved in regulating orbital fibroblast activity in Graves' Ophthalmopathy (GO). Histamine is abundantly present in granules of mast cells and is released upon mast cell activation. However, the effect of histamine on orbital fibroblasts has not been examined so far. Orbital tissues from GO patients and controls were analyzed for the presence of mast cells using toluidine blue staining and immunohistochemical detection of CD117 (stem cell factor receptor). Orbital fibroblasts were cultured from GO patients and healthy controls, stimulated with histamine and cytokines (IL-6, IL-8, CCL2, CCL5, CCL7, CXCL10 and CXCL11) were measured in culture supernatants. Also hyaluronan levels were measured in culture supernatants and hyaluronan synthase (HAS) and hyaluronidase (HYAL) gene expression levels were determined. In addition, histamine receptor subtype gene expression levels were examined as well as the effect of the histamine receptor-1 (HRH1) antagonist loratadine and NF-κB inhibitor SC-514 on histamine-induced cytokine production. Mast cell numbers were increased in GO orbital tissues. Histamine stimulated the production of IL-6, IL-8 and CCL2 by orbital fibroblasts, while it had no effect on the production of CCL5, CCL7, CXCL10, CXCL11 and hyaluronan. Orbital fibroblasts expressed HRH1 and loratadine and SC-514 both blocked histamine-induced IL-6, IL-8 and CCL2 production by orbital fibroblasts. In conclusion, this study demonstrates that histamine can induce the production of NF-κB controlled-cytokines by orbital fibroblasts, which supports a role for mast cells in GO.

Randomized phase II study of loratadine for the prevention of bone pain caused by pegfilgrastim

PURPOSE

Bone pain is a common side effect of pegfilgrastim and can interfere with quality of life and treatment adherence. This study investigated the impact of antihistamine prophylaxis on pegfilgrastim-induced bone pain.

METHODS

This is a two-stage enrichment trial design. Patients receiving an initial dose of pegfilgrastim after chemotherapy were enrolled into the observation (OBS) stage. Those who developed significant back or leg bone pain (SP) were enrolled into the treatment (TRT) stage and randomized to daily loratadine 10 mg or placebo for 7 days. SP was defined by Brief Pain Inventory as back or leg pain score ≥5 and a 2-point increase after pegfilgrastim. The primary end point of TRT was reduction of worst back or leg bone pain with loratadine, defined as a 2-point decrease after treatment compared to OBS.

RESULTS

Two hundred thirteen patients were included in the final analysis. Incidence of SP was 30.5 %. The SP subset had a worse overall Functional Assessment of Cancer Therapy-Bone Pain score (33.9 vs. 51.7, p < 0.001) and a higher mean white blood cell count (15.4 vs. 8.4 K/cm(3), p = 0.013) following pegfilgrastim than those without SP. Forty-six patients were randomized in the TRT. Benefit was 77.3 % with loratadine and 62.5 % with placebo (p = 0.35). Baseline NSAID use was documented in four patients (18.2 %) in loratadine arm and two patients (8.3 %) in placebo arm, with baseline non-NSAID use documented in five (22.7 %) and six (25 %) patients, respectively. Eight additional patients used NSAIDS by day 8 compared to day 1 (six in the loratadine and two in the placebo arm). A total of six additional patients used non-NSAIDS by day 8 compared to day 1 (four in the loratadine and two in the placebo arm).

CONCLUSIONS

Administration of prophylactic loratadine does not decrease the incidence of severe bone pain or improve quality of life in a high-risk patient population. ClinicalTrials.gov identifier: NCT01311336.

UV-Vis Spectrophotometry and Multivariate Calibration Method for Simultaneous Determination of Theophylline, Montelukast and Loratadine in Tablet Preparations and Spiked Human Plasma

Resolution of binary mixtures of theophylline (THEO), montelukast (MKST) and loratadine (LORA) with minimum sample pre-treatment and without analyte separation has been successfully achieved by multivariate spectrophotometric calibration, together with partial least-squares (PLS-1), principal component regression (PCR) and hybrid linear analysis (HLA). Data of analysis were obtained from UV-Vis spectra of three compounds. The method of central composite design was used in the ranges of 2-14 and 3-11 mg L^-1 for calibration and validation sets, respectively. The models refinement procedure and their validation were performed by cross-validation. The minimum root mean square error of prediction (RMSEP) was 0.173 mg L^-1 for THEO with PCR, 0.187 mg L^-1 for MKST with PLS1 and 0.251 mg L^-1 for LORA with HLA techniques. The limit of detection was obtained 0.03, 0.05 and 0.05 mg L^-1 by PCR model for THEO, MKST and LORA, respectively. The procedure was successfully applied for simultaneous determination of the above compounds in pharmaceutical tablets and human plasma. Notwithstanding the spectral overlapping among three drugs, as well as the intrinsic variability of the latter in unknown samples, the recoveries are excellent.

Development and evaluation of in situ nasal gel formulations of loratadine

The objective of the present work was to formulate and evaluate mucoadhesive in situ nasal gels of loratadine. This drug delivery system may overcome the first-pass metabolism and subsequently improve the bioavailability of the drug. A total of 16 formulations of in situ nasal gels were prepared using different polymeric ratios of hydroxypropyl methylcellulose (HPMC K-100) and xanthan gum. All formulations had a clear appearance in the sol form, with gelling temperature of the nasal gels ranging between 33.1 ± 0.43 and 34.8 ± 0.82 °C. The gelling time of all the formulations varied from 4.0 ± 0.21 to 11.3 ± 0.22 s; the drug content was >95%. The pH of the formulations ranged between 5.6 ± 0.004 and 6.0 ± 0.003, i.e. no mucosal irritation is expected as the pH was in the acceptable range. Mucoadhesive strength was adequate (3010.89 ± 1.21-6678.89 ± 0.45 dyne/cm(2)) to provide prolonged adhesion. In vitro drug release studies showed that the prepared formulations could release the drug for up to 10 h with all of them following Higuchi kinetics. The accelerated stability studies indicated that the gels were stable over the six months test period. The DSC and XRD analysis revealed that there was no drug-polymer interaction. From these findings it can be concluded that in situ nasal gels may be potential drug delivery systems for loratadine to overcome first-pass metabolism and thereby to improve the bioavailability.

Simultaneous determination of loratadine, desloratadine and cetirizine by capillary zone electrophoresis

PURPOSE

The aim of the study was the development of a simple and rapid analytical procedure for the determination of the most frequently used antihistamine derivatives.

METHODS

A capillary zone electrophoretic method was developed for the simultaneous separation of loratadine, desloratadine and cetirizine. Efforts were focused primarly on the optimisation of the experimental parameters: buffer composition and concentration, buffer pH, applied voltage, temperature, injection pressure and time.

RESULTS

The optimised parameters for the separation were: 25 mM buffer electrolyte, buffer pH 2.5, voltage + 25 kV, temperature 25 °C, injection pressure 50 mbar, injection time 3 seconds, capillary 48 cm (effective length 40 cm) x 50 μm, detection at 240 nm. Under these conditions, the analysis time was below 5 minutes, the order of migration being: desloratadine, cetirizine and loratadine. The developed method was validated in terms of linearity, limits of detection and quantification, intra- and inter-day precision, selectivity and robustness.

CONCLUSION

Capillary zone electrophoresis proved to be a suitable method for the simulatneous determination of the three studied antihistamine derivatives.

Modifications of histamine receptor signaling affect bone mechanical properties in rats

Histamine receptors are expressed on bone cells and histamine may be involved in regulation of bone metabolism. The aim of the present study was to investigate the effects of loratadine (an H(1) receptor antagonist), ranitidine (an H(2) receptor antagonist) and betahistine (an H(3) receptor antagonist and H(1) receptor agonist) on bone mechanical properties in rats. Loratadine (5 mg/kg/day, po), ranitidine (50 mg/kg/day, po), or betahistine dihydrochloride (5 mg/kg/day, po), were administered for 4 weeks to non-ovariectomized and bilaterally ovariectomized (estrogen-deficient) 3-month-old rats, and their effects were compared with appropriate controls. Serum levels of bone turnover markers, bone mineralization and mechanical properties of the proximal tibial metaphysis, femoral diaphysis and femoral neck were studied. In rats with normal estrogen level, administration of loratadine slightly favorably affected mechanical properties of compact bone, significantly increasing the strength of the femoral neck (p < 0.05), and tending to increase the strength of the femoral diaphysis. Ranitidine did not significantly affect the investigated parameters, and betahistine decreased the strength of the tibial metaphysis (cancellous bone, p < 0.01). There were no significant effects of the drugs on serum bone turnover markers. In estrogen-deficient rats, the drugs did not significantly affect the investigated skeletal parameters. In conclusion, the effects of histamine H(1), H(2) and H(3) receptor antagonists on the skeletal system in rats were differential and dependent on estrogen status.

Spectroscopic behavior of loratadine and desloratadine in different aqueous media conditions studied by means of TD-DFT calculations

In this study, we explained the influence of the stepwise protonation of two antihistaminic drugs on their experimental absorption spectra. We demonstrated the capability of the TD-CAM-B3LYP method, combined with a polarizable continuum model, to produce good performance for the calculated spectra. The lowest energy transitions and the molecular orbital plots were analyzed in detail. The calculated UV spectra are proposed as potential alternatives to initialize the well-known MCR-ALS algorithm, especially when the spectra of the pure analytes are not available. Moreover, it can be a useful strategy for planning an experimental methodology oriented to multiway analysis when the drug species exhibit acid-base properties.

A four-way, double-blind, randomized, placebo controlled study to determine the efficacy and speed of azelastine nasal spray, versus loratadine, and cetirizine in adult subjects with allergen-induced seasonal allergic rhinitis

Background

Azelastine has been shown to be effective against seasonal allergic rhinitis (SAR). The Environmental Exposure Unit (EEU) is a validated model of experimental SAR. The objective of this double-blind, four-way crossover study was to evaluate the onset of action of azelastine nasal spray, versus the oral antihistamines loratadine 10 mg and cetirizine 10 mg in the relief of the symptoms of SAR.

Methods

70 participants, aged 18-65, were randomized to receive azelastine nasal spray, cetirizine, loratadine, or placebo after controlled ragweed pollen exposure in the EEU. Symptoms were evaluated using the total nasal symptom score (TNSS). The primary efficacy parameter was the onset of action as measured by the change from baseline in TNSS.

Results

Azelastine displayed a statistically significant improvement in TNSS compared with placebo at all time points from 15 minutes through 6 hours post dose. Azelastine, cetirizine, and loratadine reduced TNSS compared to placebo with an onset of action of 15 (p < 0.001), 60 (p = 0.015), and 75 (p = 0.034) minutes, respectively. The overall assessment of efficacy was rated as good or very good by 46% of the participants for azelastine, 51% of the participants for cetirizine, and 30% of the participants for loratadine compared to 18% of the participants for placebo.

Conclusions

Azelastine’s onset of action for symptom relief was faster than that of cetirizine and loratadine. The overall participant satisfaction in treatment with azelastine is comparable to cetirizine and statistically superior to loratadine. These results suggest that azelastine may be preferential to oral antihistamines for the rapid relief of SAR symptoms.

A new validated liquid chromatographic method for the determination of loratadine and its impurities

An improved gradient, reversed-phase liquid chromatographic (RP-LC) method was developed and subsequently validated for the determination of Loratadine and its impurities/degradation products in pharmaceutical drug substance. Separation was achieved with Inertsil ODS-3V, 250 × 4.6 mm, 5μ column with gradient elution at a flow rate of 1.0 mL min⁻¹. UV detection was performed at 220 nm. The described method is linear over a range of LOQ (0.044, 0.088, 0.084, and 0.072 μg mL⁻¹ for impurity-B, impurity-C, impurity-D, and impurity-E respectively) to 1.2 μg mL⁻¹ (0.6 μg mL⁻¹ of the specification limit) for all the impurities and degradation products. The recovery of impurities were found to be in the range of 85–115 %. The method is simple, selective, and accurate for the quantification of impurities and degradation products of Loratadine in its bulk drug samples.