Three new anthraquinone derivatives isolated from Symplocos racemosa and their antibiofilm activity / 中国天然药物

Three new alkyl substituted anthraquinone derivatives, trivially named as symploquinones A-C (Compounds 1-3) were isolated from Symplocos racemosa. The structures of these compounds were determined on the basis of extensive spectroscopic analyses (UV, IR, Mass, H- and C-NMR, and two-dimensional (2D) NMR techniques). The resulting data were also compared with the reported literature. These compounds were then subjected to antibacterial or antibiofilm testing. Compounds 1 and 3 exhibited good antibacterial activity in the concentration range of 160-83 μg·mL against Streptococcus mutans, methicillin resistant Staphylococcus aureus and Proteus mirabilis. Both compounds were further screened for anti-biofilm activity, which revealed promising activities at sub-MIC concentrations. None of the compounds were found to be active against Klebsiella pneumoniae.

Comparative evaluation of various solubility enhancement strategies for furosemide

Drugs with good solubility exhibit good oral absorption, and subsequently good bioavailability. Thus, most exigent phase of drug development practice particularly for oral dosage forms is the enhancement of drug solubility. This review describes various traditional and novel methodologies proposed for the solubility enhancement of furosemide. For furosemide, solubility and permeability are crucial rate limiting factors to achieve its desired level in systemic circulation for pharmacological response. Thus, problematic solubility of furosemide is one of the main challenges for dosage form developing researchers. Various procedures, illustrated in this review, have been successfully employed to improve the furosemide solubility; however successful improvement essentially depends on the assortment of technique. It is concluded from the results that dissolution rate of drug increases by increasing the quantity of solubility enhancer. Dissolution rate also depends upon the type of enhancer and dissolution medium. In order to achieve relatively enhanced percentage drug release after 30 min [DP[30]], complexation by solvent evaporation using beta-cyclodextrin is the best method. Solid dispersion is found the best if polyethylene glycol is used as enhancer along with microcrystalline cellulose as hydrophilic adsorbent. All the approaches narrated in this article possess good perceptions for additional research i.e. in-vivo studies should be carried out focusing on delivery system development

In vitro-in vivo correlation study on nimesulide loaded hydroxypropylmethylcellulose microparticles / 药学学报

This study involves mathematical simulation model such as in vitro-in vivo correlation (IVIVC) development for various extended release formulations of nimesulide loaded hydroxypropylmethylcellulose (HPMC) microparticles (M1, M2 and M3 containing 1, 2, and 3 g HPMC, respectively and 1 g drug in each) having variable release characteristics. In vitro dissolution data of these formulations were correlated to their relevant in vivo absorption profiles followed by predictability worth analysis of these Level A IVIVC. Nimaran was used as control formulation to validate developed formulations and their respective models. The regression coefficients of IVIVC plots for M1, M2, M3 and Nimaran were 0.834 9, 0.831 2, 0.927 2 and 0.898 1, respectively. The internal prediction error for all formulations was within limits, i.e., < 10%. A good IVIVC was found for controlled release nimesulide loaded HPMC floating M3 microparticles. In other words, this mathematical simulation model is best fit for biowaiver studies which involves study parameters as those adopted for M3 because the value of its IVIVC regression coefficient is the closest to 1 as compared to M1 and M2.