Efficient drug development of oseltamivir capsules based on process control, bioequivalence and PBPK modeling.

Oseltamivir phosphate is used to treat influenza. For registration of a generic product, bioequivalence studies are crucial, however, in vitro studies can sometimes replace the conventional human pharmacokinetic. To assess whether the dissolution profile is comparable with the in vivo release, physiologically based pharmacokinetic absorption models (PBPK) are being used. The aim of the study was to develop a generic capsule of oseltamivir phosphate 30 mg with process understanding and control, development of PBPK model and comparison of virtual bioequivalence study (VBE) to the real bioequivalence study that was also performed. For that, 30 mg capsules were prepared by wet granulation according to 22 full factorial design. The biobatch was prepared with the selected process and a batch was made with the API from the second manufacture. Both manufactures presented polymorph A and the second manufacture showed higher particle size. Product batches produced without adding water during granulation showed higher dissolution. The addition of water associated with higher conical mill speed, lowered the average weight of the capsules. The biobatch dissolution was similar to Tamiflu; also, they were bioequivalent. The crossover VBE between the biobatch and Tamiflu corroborated with the real bioequivalence study. The same result was found for the batch with higher particle size. PBPK model showed that computer simulations can help pharmaceutical companies to replace in vivo studies.

Chemical profile and antinociceptive efficacy of Rheedia longifolia leaf extract.

Different species of the family Clusiaceae, including Rheedia longifolia, are used in folk medicine to treat inflammatory diseases. This family is largely distributed in tropical and subtropical areas of Brazil, but their chemical and pharmacological properties have been the subject of a few studies. In previous studies, we found that the aqueous extract from R. longifolia leaves presented important anti-inflammatory and analgesic activity. We investigated the chemical profile of R. longifolia and characterized the pharmacological effect of different chemically identified fractions in pharmacological models of neurogenic and inflammatory nociception. The pharmacological tests showed that oral treatment with aqueous crude extract and fractions of methanol extract of R. longifolia leaf induced a significant antinociceptive effect using von Frey filaments. In addition, the most polar fractions presented antinociceptive activity in a neurogenic model of nociception (capsaicin model). The chromatographic analysis indicated the presence of bisflavonoids in the fractions obtained from the methanol extract. These results suggest that bisflavonoids found in methanol-extracted fractions are involved in the inhibition of inflammatory and neurogenic nociception. It is important that the R. longifolia aqueous extract treatment inhibited ulcer formation induced by indomethacin, suggesting an anti-ulcerogenic activity closely associated with its analgesic effect.