Three dimensional macroporous hydroxyapatite/chitosan foam-supported polymer micelles for enhanced oral delivery of poorly soluble drugs was written by Zhang, Yanzhuo;Dong, Kai;Wang, Fang;Wang, Hongtao;Wang, Jing;Jiang, Ziqiu;Diao, Shuai. And the article was included in Colloids and Surfaces, B: Biointerfaces in 2018.Electric Literature of C33H34N6O6 This article mentions the following:
In the current study, a novel three-dimensional macroporous hydroxyapatite/ chitosan foam (HA/CS)-supported polymer micelle (PM/HA/CS) was developed, and its potential as an oral drug delivery system to enhance the solubility and oral bioavailability of poorly soluble compounds was systemically studied. Candesartan cilexetil (CC) was selected as a poorly soluble model drug. Firstly, HA/CS foam was synthesized using a wet chem. co-precipitation approach and poly-(Me methacrylate) colloidal crystals as a macropore template. Subsequently, the CC-loaded polymer micelles were efficiently encapsulated into the macropores of the HA/CS foam and freeze-dried to produce powdery CC-loaded PM/HA/CS composites (CC-PM/HA/CS). The resulting CC-PM/HA/CS particles were then characterized in terms of porous structure, morphol., angle of repose, crystallinity, drug loading, dissolution profiles, and phys. stability. Differential scanning calorimetry (DSC) anal. confirmed that CC-PM/HA/CS was present in an amorphous form and has an excellent phys. stability. Under both simulated gastric and intestinal conditions, the aqueous solubility and dissolution rate of the PM/HA/CS-based CC formulation were significantly increased compared with the pure drug powder. In addition, PM/HA/CS is almost completely non-cytotoxic. The PM/HA/CS-based CC formulation produced approx. 1.9-fold increased bioavailability when compared to the marketed tablets (Blopress) administered to fasted Sprague-Dawley rats. On the whole, PM/HA/CS benefits from the advantages of three dimensional macroporous HA/CS foam and polymer micelles, and exhibits great potential as a drug delivery system for increasing the solubility and oral bioavailability of a poorly soluble compound, like CC. In the experiment, the researchers used many compounds, for example, 1-(((Cyclohexyloxy)carbonyl)oxy)ethyl 1-((2′-(2H-tetrazol-5-yl)-[1,1′-biphenyl]-4-yl)methyl)-2-ethoxy-1H-benzo[d]imidazole-7-carboxylate (cas: 145040-37-5Electric Literature of C33H34N6O6).
1-(((Cyclohexyloxy)carbonyl)oxy)ethyl 1-((2′-(2H-tetrazol-5-yl)-[1,1′-biphenyl]-4-yl)methyl)-2-ethoxy-1H-benzo[d]imidazole-7-carboxylate (cas: 145040-37-5) belongs to imidazole derivatives. Many natural products, especially alkaloids, contain the imidazole ring. These imidazoles share the 1,3-C3N2 ring but feature varied substituents. Imidazole is incorporated into many important biological compounds. The most pervasive is the amino acid histidine, which has an imidazole side-chain. Histidine is present in many proteins and enzymes, e.g. by binding metal cofactors, as seen in hemoglobin.Electric Literature of C33H34N6O6
Referemce:
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem