(2014) Comparative pharmacokinetics of a marker compound, baicalin in KOB extract after oral administration to normal and allergic-induced rats, Drug Delivery, 21:6, 453-458, DOI: 10.3109/10717544.2013 Abstract KOB extracts are a polyherbal medicine had been prescribed for the treatment of hyperhydrosis and allergic diseases such as allergic asthma and rhinitis in oriental clinics. Therefore, the pharmacokinetic studies of the KOB extract administered orally to normal rats and rhinitisinduced rats to understand the correlation of the efficacy and plasma concentration of KOB in patients of allergic rhinitis in future were performed. The study was conducted according to administration for pure baicalin in normal rats, baicalin in KOB extract in normal rats and rhinitis-induced rats. Baicalin in rat plasma was analyzed and validated by HPLC analysis. The interday precision based on the standard deviation of replicates of quality control samples ranged from 3.6% to 7.9% with accuracy ranging from 92.9% to 101.2% for baicalin. Based on validated analysis, pharmacokinetic study was carried out. Pure baicalin in normal rats and baicalin in KOB extract in normal rats showed bimodal curves due to direct absorption and glucuronidation. The T max , C max and AUC of pure baicalin in normal rats or baicalin in KOB extract in normal rats were 12 h, 0.68 mg/ml and 9.85 mg h/ml, respectively, or 12 h, 0.46 mg/ml and 6.36 mg h/ml, respectively. The analytical method showed excellent sensitivity, precision and accuracy, being successfully employed in a pharmacokinetic study of polyherbal medicine, KOB extract. Allergic-induced condition did not affect the pharmacokinetics of KOB extracts, suggesting KOB extracts did not require dosage adjustment in subjects with allergic-induced diseases.

Background: Gemcitabine must be administered at high doses to elicit the required therapeutic response because of its very short plasma half-life due to rapid metabolism. These high doses can have severe adverse effects. Methods: In this study, polymeric microparticulate systems of gemcitabine were prepared using chitosan as a mucoadhesive polymer and Eudragit L100-55 as an enteric copolymer. The physicochemical and biopharmaceutical properties of the resulting systems were then evaluated. Results: There was no endothermic peak for gemcitabine in any of the polymeric gemcitabine microparticulate systems, suggesting that gemcitabine was bound to chitosan and Eudragit L100-55 and its crystallinity was changed into an amorphous form. The polymeric gemcitabine microparticulate system showed more than 80% release of gemcitabine in 30 minutes in simulated intestinal fluid. When mucin particles were incubated with gemcitabine polymeric microparticulates, the zeta potential of the mucin particles was increased to 1.57 mV, indicating that the polymeric gemcitabine microparticulates were attached to the mucin particles. Furthermore, the F53 polymeric gemcitabine microparticulates having 150 mg of chitosan showed a 3.8-fold increased uptake of gemcitabine into Caco-2 cells over 72 hours compared with gemcitabine solution alone. Conclusion: Overall, these results suggest that polymeric gemcitabine microparticulate systems could be used as carriers to help oral absorption of gemcitabine.

Gemcitabine microparticles were prepared using chitosan, polyethylene oxide or carbopol as the mucoadhesive polymer and eudragit L100-55 as the enteric polymer by a double emulsion method. The particle size and zeta potential changed from 1338.3 ± 254.1 nm to 2459.4 ± 103.6 nm and -5.16 ± 1.62 mV to 2.84 ± 0.65 mV, respectively, with increasing chitosan to gemcitabine weight ratio from 0.25 to 1. The gemcitabine-loaded microparticles without mucoadhesive polymer (F50) showed the particle size and zeta potential of 671.3 ± 58.3 nm and - 16.7 ± 1.82 mV, respectively. The cellular uptake of gemcitabine into Caco-2 cells from gemcitabine-loaded microparticles with chitosan increased with increasing incubation time in Caco-2 cells compared to that of gemcitabine-loaded microparticles with polyethylene oxide or carbopol, suggesting that chitosan might be the optimal mucoadhesive polymer. Gemcitabine microparticles will be tested to identify whether the oral absorption could be increased in the future.

Allergic rhinitis (AR) is characterized by inflammation of the nasal mucosa with hypersensitivity resulting from seasonal or perennial responses to specific environmental allergens and by symptoms like nasal rubbing, sneezing, rhinorrhea, lacrimation, nasal congestion and obstruction, and less frequently cough. KOB extracts, which is a polyherbal medicine consisting of 5 different herbs (Atractylodes macrocephala, Astragalus membranaceus, Saposhnikovia divaricata, Ostericum koreanum and Scutellaria baicalensis) had commonly been used for the treatment of various allergic diseases showed an anti-allergic effect by modulating mast cell-mediated allergic responses in allergic rhinitis, recently. On the other hand, pseudoephedrine is a sympathomimetic amine commonly used to relieve congestion in patients with allergic rhinitis and common colds. Considering the KOB's therapeutic mechanism, the combination with pseudoephedrine would be suitable for allergic rhinitis. This study is to obtain an effective extended release formulation using pseudoephedrine and KOB extracts to reduce side effects of drug due to repeated dosing and improve the compliance of patients for treatment of rhinitis and nasal decongestion. So, the fixed-dose combination tablet of pseudoephedrine and KOB extracts was prepared by direct compression and characterized by drug content, flowing characteristics and dissolution test. The drug content of baicalin of KOB extracts was within the range of 95-105% except for T1 formulation. The hardness and friability values of all formulations ranged from 9 to 13 kp and less than 1%, respectively. Taken together, T4 or T8 could be a stable fixed-dose combination tablet for extended release of pseudoephedrine and KOB extracts for nasal rhinitis.