Priprava i ex vivo evaluacija TEC kao promotora apsorpcije tvari u kolonu

In previous studies, it was established that chitosan and its quaternized derivatives are potent enhancers of hydrophilic compounds absorption across intestinal epithelia. The aim of this study was to evaluate the application of a new quaternized chitosan, triethyl chitosan (TEC), in pharmaceutical approaches. TEC was synthesized by a one step process via a 22 factorial design to optimize the preparation conditions. In ex vivo experiments, everted rat colon sac was used to determine the effect of TEC on the penetration of hydrophilic compounds of different molecular masses (e.g., sodium fluorescein and brilliant blue) through colonic epithelia in comparison with chitosan at pH 7.4. These studies indicated a significant increase in absorption of sodium fluorescein and brilliant blue in the presence of TEC compared to chitosan. TEC bearing positive charge is able to interact with the tight junctions of colon epithelia and hence increase the permeation of sodium fluorescein and brilliant blue through the tight junctions. This investigation has shown that triethyl chitosan could be used as a penetration enhancer for poorly absorbable compounds in the colon drug delivery system.U ranijim istraživanjima utrđeno je da su kitozan i njegovi kvartenizirani derivati snažni promotori apsorpcije hidrofilnih spojeva kroz intestinalnu sluznicu. Cilj rada bio je evaluirati novi kvartenizirani kitozan, trietil kitozan (TEC ).TEC je sintetiziran u jednom stupnju. U ex vivo eksperimentima na kolonu štakora praćen je učinak tog polimera na penetraciju hidrofilnih spojeva različitih molekulskih masa (fluorescein natrija i briljant plavila). Rezultati su uspoređivani s učinkom kitozana na pH 7,4. Primjećeno je da TEC značajno povećava apsorpciju ispitivanih tvari u odnosu na nemodificirani kitozan. TEC svojim pozitivnim nabojem dolazi u interakciju s epitelom kolona i tako povećava njegovu permeabilnost. Ispitivanja ukazuju da se trietil kitozan može upotrijebiti kao promotor penetracije za spojeve koji se slabo apsorbiraju u kolonu

Priprava i ex vivo evaluacija TEC kao promotora apsorpcije tvari u kolonu

In previous studies, it was established that chitosan and its quaternized derivatives are potent enhancers of hydrophilic compounds absorption across intestinal epithelia. The aim of this study was to evaluate the application of a new quaternized chitosan, triethyl chitosan (TEC), in pharmaceutical approaches. TEC was synthesized by a one step process via a 22 factorial design to optimize the preparation conditions. In ex vivo experiments, everted rat colon sac was used to determine the effect of TEC on the penetration of hydrophilic compounds of different molecular masses (e.g., sodium fluorescein and brilliant blue) through colonic epithelia in comparison with chitosan at pH 7.4. These studies indicated a significant increase in absorption of sodium fluorescein and brilliant blue in the presence of TEC compared to chitosan. TEC bearing positive charge is able to interact with the tight junctions of colon epithelia and hence increase the permeation of sodium fluorescein and brilliant blue through the tight junctions. This investigation has shown that triethyl chitosan could be used as a penetration enhancer for poorly absorbable compounds in the colon drug delivery system.U ranijim istraživanjima utrđeno je da su kitozan i njegovi kvartenizirani derivati snažni promotori apsorpcije hidrofilnih spojeva kroz intestinalnu sluznicu. Cilj rada bio je evaluirati novi kvartenizirani kitozan, trietil kitozan (TEC ).TEC je sintetiziran u jednom stupnju. U ex vivo eksperimentima na kolonu štakora praćen je učinak tog polimera na penetraciju hidrofilnih spojeva različitih molekulskih masa (fluorescein natrija i briljant plavila). Rezultati su uspoređivani s učinkom kitozana na pH 7,4. Primjećeno je da TEC značajno povećava apsorpciju ispitivanih tvari u odnosu na nemodificirani kitozan. TEC svojim pozitivnim nabojem dolazi u interakciju s epitelom kolona i tako povećava njegovu permeabilnost. Ispitivanja ukazuju da se trietil kitozan može upotrijebiti kao promotor penetracije za spojeve koji se slabo apsorbiraju u kolonu

Formulation and Evaluation of Extended- Release Tablet of Zolpidem Tartrate by Wet Granulation Technique

The goal of this study was to design and evaluate extended - release system of the hypnotic agent, Zolpidem tartrate usefulness for the treatment of insomnia. The half-life of this drug is about 1.9 - 3 hours that indicating it a candidate for the extended release formulation. Our investigation relates to development of extended drug delivery system based on Hydroxy propyl methyl cellulose (HPMCK4M) as release retardant, polyvinyl pyrrolidone (PVP k30) as binder and Magnesium Stearate using Factorial design. In vitro release study of matrix tablets was carried out in 0.01N HCl for 2 hours. All prepared matrix tablets were evaluated for physicochemical evaluation and drug content. The formulation that had release profile according to United State Pharmacopoeia selected for stability study according to ICH guidelines

Preparation and In vitro Characterization of Alprazolam Extended- Release Tablets Using HPMC 4000cps

The main aim of this study was preparation and evaluation of extended - release system of the anxiolytic substance. Alprazolam is a short-acting benzodiazepine with general properties similar to those of diazepam. Our studies focused on development of extended drug delivery system based on Hydroxy Propyl Methyl Cellulose (HPMC 4000cps) as retard agent and Polyvinylpyrrolidone (PVP k30) as binder using factorial design. All prepared matrix tablets were considered for physicochemical evaluation and drug content. In vitro release study of matrix tablets for all formulations has shown that HPMC is the main component in retarding of alprazolam in dissolution medium. The optimum formulation (30% HPMC 4000 and 10% PVP) with suitable release profile according to criteria of United State Pharmacopoeia has selected for stability studies according to ICH guidelines

Preparation and Skin Permeation Study of N, N- Diethyl- meta-Toluamide Semi Solid Formulations

N,N-Diethyl meta Toluamide (DEET) is an insect repellent agent that contrary to its benefits, if is used in formulations with high skin permeation, will produce side effects of different severity. This study attempted to achieve a semi-solid DEET containing formulation with good appearance, sufficient spreadity, suitable viscosity for tube and jar filling, compatible pH with skin, reasonable stability, longer release time, and the less skin permeation. To obtain such a formulation, three types of DEET containing semi solids including gels (hydrophile), creams (emulsion) and ointments (lipophile), and their characteristics were compared with each other and with Off! Brand. Results showed that one of the prepared creams with the proper viscosity, stability, appearance and spreadity, had the least drug release in six hours and less skin permeation of DEET as compared with Off!. Hence the preparation was introduced as the optimal formulation