Effect of TA-270, a novel quinolinone derivative, on antigen-induced nasal blockage in a guinea pig model of allergic rhinitis

Exploring the synthetic potential of epoxide ring opening reactions toward the synthesis of alkaloids and terpenoids: a review

Epoxides are oxygen containing heterocycles which are significantly employed as crucial intermediates in various organic transformations. They are considered highly reactive three-membered heterocycles due to ring strain and they undergo epoxide ring opening reactions with diverse range of nucleophiles. Epoxide ring-opening reactions have gained prominence as flexible and effective means to obtain various functionalized molecules. These reactions have garnered substantial attention in organic synthesis, driven by the need to comprehend the synthesis of biologically and structurally important organic compounds. They have also found applications in the synthesis of complex natural products. In this review article, we have summarized the implementation of epoxide ring opening reactions in the synthesis of alkaloids and terpenoids based natural products reported within the last decade (2014-2023).

Synthesis of 3-Hydroxy-4-arylquinolin-2-ones Including Viridicatol via a Darzens Condensation/Friedel-Crafts Alkylation Strategy

The new efficient synthesis of biologically important 3-hydroxy-4-arylquinolin-2-ones through the Darzens condensation (epoxidation) of dichloroacetanilides with aromatic aldehydes followed by one-pot dechlorative epoxide-arene cyclization is described. This methodology has been utilized for the synthesis of naturally occurring viridicatol, a fungal metabolite isolated from the penicillium species.

Alcaftadine for the Prevention of Itching Associated with Allergic Conjunctivitis

OBJECTIVE:

To evaluate the safety and efficacy of alcaftadine for the prevention of itching associated with allergic conjunctivitis.

DATA SOURCES:

A medical literature search was conducted in MEDLINE/PubMed (2006-February 2012) and EMBASE (2006-February 2012) using the search terms alcaftadine and Lastacaft. References from these publications were reviewed for additional resources. Additional information was collected from Web sites of the US government ( http://www.clinicaltrials.gov , http://www.fda.gov ) and of Allergan Inc., the manufacturer of Lastacaft ( http://www.lastacaft.com ).

STUDY SELECTION AND DATA EXTRACTION:

All identified articles and publications in English were reviewed for pharmacology, pharmacokinetics, efficacy, and safety data. Priority was placed on clinical trials.

DATA SYNTHESIS:

Two published clinical trials evaluated the efficacy of alcaftadine in the prevention of ocular itching and conjunctival redness associated with allergic conjunctivitis. One trial compared alcaftadine to placebo, and another trial compared alcaftadine to placebo and olopatadine HCl to placebo. Both studies showed superior efficacy, both clinically and statistically, in the prevention of ocular itching associated with allergic conjunctivitis compared to placebo. Although conjunctival redness was evaluated in the 2 trials, neither trial demonstrated both clinical and statistical significance. Both trials demonstrated a rapid onset of action of less than 15 minutes, as well as a duration of action greater than 16 hours, which supports the use of once-daily administration. Overall, alcaftadine was well tolerated, and common adverse effects, reported in less than 4% of patients, included ocular irritation, pruritus, erythema, and stinging or burning upon instillation. Ocular adverse effects were typically mild in severity and self-limiting.

CONCLUSIONS:

Alcaftadine is a safe and effective option for the prevention of ocular itching associated with allergic conjunctivitis, is dosed once daily, and is competitively priced among prescription medications for allergic conjunctivitis. Additional studies are needed to further evaluate the comparative efficacy among ocular antihistamine/mast cell stabilizing medications.

Clinical pharmacology of alcaftadine, a novel antihistamine for the prevention of allergic conjunctivitis

PURPOSE

In this report, we characterize the in vitro pharmacokinetic properties of a new antihistamine, alcaftadine. In addition, we report results from phase 1 studies of several ophthalmic formulations of alcaftadine and examine the pharmacokinetic properties of one formulation in detail.

METHODS

In vitro pharmacology employed a human liver microsome assay combined with index substrates or inhibitors for specific cytochromes. Metabolic fate of (14)C-alcaftadine was determined by high-performance liquid chromatography-based separation of parent compound from metabolites. Plasma protein binding was determined by equilibrium dialysis using (3)H-labeled alcaftadine and (3)H-labeled alcaftadine carboxylic acid metabolite. Relative tolerability (comfort) of 4 concentrations and 3 formulations of alcaftadine ophthalmic solution was assessed in 2 double-masked, randomized, placebo-controlled, contralateral studies in which formulations were compared to Tears Naturale II (placebo) in normal adult subjects. Data analysis focused on the mean differences in subject-reported drop comfort scores (within each dose level, at each time point) and compared the study-treatment eye with the placebo eye. Pharmacokinetics of alcaftadine 0.25% ophthalmic solution were determined in an open-label, single-center study after a single bilateral dose and after 7 days of once-a-day bilateral doses in healthy subjects 18-55 years old.

RESULTS

Alcaftadine is not significantly metabolized by microsomal cytochromes, but it is rapidly converted to the carboxylic acid metabolite by one or more cytosolic enzymes. Neither the parent compound nor its carboxylic acid metabolite displayed significant plasma protein binding. Over a range of formulations and concentrations (0.05%-0.5%), alcaftadine was well tolerated and subjects reported little or no discomfort or taste perversion in any treatment group. Pharmacokinetic studies showed that both the parent compound and the carboxylic acid metabolite reach peak serum levels within minutes of administration and fall below detectable levels within 3 h of dosing.

CONCLUSIONS

Based upon pharmacokinetic and phase 1 studies, the novel antihistamine alcaftadine is an appropriate drug for use as an ophthalmic formulation for prevention and treatment of ocular allergic conditions such as allergic conjunctivitis (alcaftadine ophthalmic solution 0.25% was recently approved for use by the FDA). Topical administration of alcaftadine 0.25% ophthalmic solution was well tolerated and had an acceptable safety profile.