Gofex Mechanism of Action

Pharmacotherapeutic group: Anti-inflammatory and anti-rheumatic products, non-steroids, propionic acid derivatives. Ibuprofen is a synthetic analgesic-anti-inflammatory drug with a marked antipyretic action.
Pharmacology: Pharmacodynamics: Mechanism of action: Ibuprofen is the first phenylpropionic acid derivative. It is a prostaglandin synthetase inhibitor with analgesic, antipyretic and anti-inflammatory properties. It possesses a nonnarcotic analgesic activity. The mechanism of action of ibuprofen (insitu formation of L-arginine salt) is linked to the reversible inhibition of the COX enzyme, responsible for conversion of arachidonic acid into cyclic endoperoxides, hence reducing the synthesis of thromboxane (TXA2), prostacyclins (PGI2) and prostaglandins (PG).
Pharmacokinetics: On oral application, ibuprofen is partly absorbed in the stomach and then completely in the small intestine. After absorption, ibuprofen is conjugated to plasma-proteins for about 99% and is mainly distributed throughout the plasma compartment. It diffuses slowly into the synovial spaces and is eliminated more slowly from these spaces than it is from the plasma. Ibuprofen is metabolized in the liver mainly by hydroxylation and carboxylation of the isobutyl group. The metabolites have no known pharmacological activity. The plasma half-life is 1-2 hours. Over 90% of dosage can be found in the urine as metabolites and their conjugates. Less than 1% is excreted unchanged in the urine.
Bioequivalence Study Result: Bioequivalence study was carried out on Gofen soft capsules 400 mg (produced by Mega Lifesciences Ltd., Thailand) compared with Nurofen 400 caplets (produced by Reckitt Benckiser Healthcare Manufacturing Ltd., Thailand) with an open label balanced, randomized, two-treatment, two-period, two-sequence, single dose, crossover study design, in 28 healthy subjects in fasting conditions. Study results showed that test drug is bioequivalent to reference drug with GMR AUC0-t, AUC0-~ and Cmax value 95.72%, 93.93% and 119.81% respectively with a 90% CI values 90.98-100.71%, 90.02-98.02% and 109.73-130.82%.
Results of Comparative Dissolution Test (CDT) carried out between test drug (Gofen soft capsules 400 mg) and reference drug (Nurofen caplets 400 mg) at 3 pH (0.1 N HCl medium, pH 4.5 acetate buffer, and phosphate buffer pH 6.8) are 94.95%, 62.77%, and 69.78% respectively. The results at these three pH showed that the two products are similar with F2 value ≥50.0.
Results of Comparative Dissolution Test (CDT) carried out between comparator used in the BE study (Nurofen caplet 400 mg) and innovator approved in Indonesia (Spedifen tablet 400 mg) in 3 pH (medium HCl 0.1 N, acetate buffer pH 4.5, and phosphate buffer pH 6.8) are 79.51%, 56.30% and 64.24% respectively. The results on these three pH levels showed that the two products are similar with F2 value ≥50.0.