Fizičkokemijska karakterizacija inkluzijskih kompleksa celekoksiba s beta-ciklodekstrinom i oslobađanje celekoksiba in vitro

In this study, attempts were made to investigate the effects of betha-cyclodextrin (betha-CD) on the aqueous solubility and dissolution rate of celecoxib. Inclusion complexes were prepared by the kneading method and characterized by SEM, NMR, IR, DSC, and X-ray powder diffraction. Dissolution rate of the complexes was significantly greater than that of the corresponding physical mixtures and pure drug, indicating that the formation of inclusion complex increased the solubility of the poorly soluble drug celecoxib.U radu je ispitivan utjecaj beta-ciklodekstrina (beta-CD) na vodotopljivost i oslobađanje celekoksiba iz inkluzijskih kompleksa. Kompleksi su priređeni metodom gnječenja i karakterizirani pomoću SEM, NMR, IR, DSC i difrakcijom rentgenskim zračenjem. Oslobađanje iz kompleksa bilo je značajno bolje nego iz fizičke smjese što ukazuje da je stvaranje inkluzijskog kompleksa povećalo topljivost teško topljivog celekoksiba

Pre-formulation and systematic evaluation of amino acid assisted permeability of insulin across in vitro buccal cell layers

The aim of this work was to investigate alternative safe and effective permeation enhancers for buccal peptide delivery. Basic amino acids improved insulin solubility in water while 200 and 400 µg/mL lysine significantly increased insulin solubility in HBSS. Permeability data showed a significant improvement in insulin permeation especially for 10 µg/mL of lysine (p < 0.05) and 10 µg/mL histidine (p < 0.001), 100 µg/mL of glutamic acid (p < 0.05) and 200 µg/mL of glutamic acid and aspartic acid (p < 0.001) without affecting cell integrity; in contrast to sodium deoxycholate which enhanced insulin permeability but was toxic to the cells. It was hypothesized that both amino acids and insulin were ionised at buccal cavity pH and able to form stable ion pairs which penetrated the cells as one entity; while possibly triggering amino acid nutrient transporters on cell surfaces. Evidence of these transport mechanisms was seen with reduction of insulin transport at suboptimal temperatures as well as with basal-to-apical vectoral transport, and confocal imaging of transcellular insulin transport. These results obtained for insulin is the first indication of a possible amino acid mediated transport of insulin via formation of insulin-amino acid neutral complexes by the ion pairing mechanism