PENGARUH PENAMBAHAN POLIETILEN GLIKOL 6000 PADA TABLET IBUPROFEN DISPERSI PADAT TERHADAP ABSORBSI IBUPROFEN SECARA IN SITU

Drug absorption can be decided by various methods, namely in vitro methods, in situ methods, and in vivo methods. The in situ method is a procedure that is very close to the in vivo method. The aim of this study was to identify the effect of accumulation of polyethylene glycol 6000 (PEG 6000) on solid dispersion of ibuprofen tablets on the in-situ absorption of the drug. This research was conducted through an experiment to determine the effect of adding polyethylene glycol 6000 to the absorption of ibuprofen in situ by flowing the solution from solid dispersion ibuprofen tablets, solutions from generic ibuprofen tablets and standard ibuprofen solutions. The solid dispersion system was carried out by melting ibuprofen and polyethylene glycol 6000 in a ratio of 1:05. The drug solution was flowed through the lumen of the small intestine of male rats. Unabsorbed ibuprofen was measured by an ultraviolet spectrophotometer at a wavelength of 225.5 nm. Next, the absorbed level of ibuprofen was calculated. The results showed that ibuprofen from solid dispersion tablets was absorbed more than ibuprofen from generic tablets and standard ibuprofen. It can be concluded that polyethylene glycol 6000 has an effect on the absorption of ibuprofen in situ.

Electrochemical properties and optical response of cadmium selenide quantum dot film electrodes

Electrochemical charge/discharge mechanisms in the electrophoretically deposited CdSe quantum dot (QD)film electrodes in NBu4PF6 acetonitrile solution have been investigated. The films were deposited from CdSe colloidal solution in nitrobenzene at variable QD size (diameter) from 3.4 to 6.3 nm onto transparent conducting glass substrates. Electrochemical behavior and optical response were characterized by cyclic voltammetry (CV) and in situ absorption spectroscopy. Electrochemical charging under an inert gas atmosphere results in a reversible color change (electrochromism), due to the bleach of exciton absorption with 0.3 optical density changes. The mechanism of electrochemical charging comprises electron transfer from conducting substrate to QD, interparticle transfer and also electron capturing by acceptors in solution. The introduction of a strong electron acceptor (O2) into the solution results in a suppression of electrochromism. The influence of oxygen is rather reversible which is observed from recovered electrochromic behavior after electrolyte resaturation with argon.

Cubic Microcontainers Improve In Situ Colonic Mucoadhesion and Absorption of Amoxicillin in Rats

An increased interest in colonic drug delivery has led to a higher focus on the design of delivery devices targeting this part of the gastrointestinal tract. Microcontainers have previously facilitated an increase in oral bioavailability of drugs. The surface texture and shape of microcontainers have proven to influence the mucoadhesion ex vivo. In the present work, these findings were further investigated using an in situ closed-loop perfusion technique in the rat colon, which allowed for simultaneous evaluation of mucoadhesion of the microcontainers as well as drug absorption. Cylindrical, triangular and cubic microcontainers, with the same exterior surface area, were evaluated based on in vitro release, in situ mucoadhesion and in situ absorption of amoxicillin. Additionally, the mucoadhesion of empty cylindrical microcontainers with and without pillars on the top surface was investigated. From the microscopy analysis of the colon sections after the in situ study, it was evident that a significantly higher percentage of cubic microcontainers than cylindrical microcontainers adhered to the intestinal mucus. Furthermore, the absorption rate constants and blood samples indicated that amoxicillin in cubic microcontainers was absorbed more readily than when cylindrical or triangular microcontainers were dosed. This could be due to a higher degree of mucoadhesion for these particular microcontainers.

Investigating two-step MAPbI3 thin film formation during spin coating by simultaneous in situ absorption and photoluminescence spectroscopy

Here we investigate the two-step MAPbI3 thin film formation during spin coating by simultaneous in situ absorption and photoluminescence spectroscopy.

Shifting the equilibrium of methanol synthesis from CO2 by in situ absorption using ionic liquid media

A promising way to increase the methanol yields in CO2 hydrogenation significantly up to 60% by in situ sorption of methanol and water in alkali salt-doped ionic liquids (ILs) is demonstrated.

Regional Absorption of Fimasartan in the Gastrointestinal Tract by an Improved in situ Absorption Method in Rats

The aim of the present study was to assess the regional absorption of fimasartan by an improved in situ absorption method in comparison with the conventional in situ single-pass perfusion method in rats. After each gastrointestinal segment of interest was identified, fimasartan was injected into the starting point of each segment and the unabsorbed fimasartan was discharged from the end point of the segment. Blood samples were collected from the jugular vein to evaluate the systemic absorption of the drug. The relative fraction absorbed (Fabs,relative) values in the specific gastrointestinal region calculated based on the area under the curve (AUC) values obtained after the injection of fimasartan into the gastrointestinal segment were 8.2% ± 3.2%, 23.0% ± 12.1%, 49.7% ± 11.5%, and 19.1% ± 11.9% for the stomach, duodenum, small intestine, and large intestine, respectively, which were comparable with those determined by the conventional in situ single-pass perfusion. By applying the fraction of the dose available at each gastrointestinal segment following the oral administration, the actual fraction absorbed (F’abs) values at each gastrointestinal segment were estimated at 10.9% for the stomach, 27.1% for the duodenum, 40.7% for the small intestine, and 5.4% for the large intestine, which added up to the gastrointestinal bioavailability (FX·FG) of 84.1%. The present method holds great promise to assess the regional absorption of a drug and aid to design new drug formulations.