Dissolution enhancement of cefdinir with hydroxypropyl-ß-cyclodextrin.

The solid state properties and dissolution behavior of binary systems of cefdinir (CEF) with hydroxypropyl-ß-cyclodextrin (HP-ß-CD) were investigated. CEF-HP-ß-CD interaction in the solution state was studied by phase-solubility analysis and demonstrates the ability of HP-ß-CD to complex with CEF giving A(L) type profile with 65.28 ± 1.3 M⁻¹ stability constant. The freeze drying technique was adopted to prepare binary systems of CEF with HP-ß-CD in 1:1 molar ratio. The solid inclusion was characterized by fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), X-ray powder diffractometry (XRD), and scanning electron microscopy (SEM). Aqueous solubility of CEF-HP-ß-CD inclusion complex was 2.36-fold of pure CEF. The dissolution profiles of inclusion complexes were determined and compared with those of CEF alone and their physical mixtures. The dissolution rate of inclusion complex was superior than the CEF alone. These approaches indicated that CEF was able to form an inclusion complex with HP-ß-CD, and the inclusion compounds exhibited different spectroscopic features and properties.

In vitro and in vivo studies of galactose-modified liver-targeting liposomes.

Oridonin (ORI) is a bioactive diterpenoid compound extracted from the well known Chinese traditional medicine Rabdosia rubescens. The aim of this study was to prepare ORI loaded liposomes surface-modified with galactose (NOH-ORI-LP) and evaluate their characteristics compared with ORI loaded liposomes (ORI-LP) and ORI solution in vitro and in vivo. The NOH-ORI-LP was prepared by ethanol injection method. The NOH-ORI-LP was characterized by their morphology, particle size, zeta potential and encapsulation efficiency. The concentration of ORI in plasma and tissues at different sampling time points were determined. The liver concentration-time curves of NOH-ORI-LP in mice were determined, and the pharmacokinetic parameters were calculated and compared by statistical analysis. Our data revealed that NOH-ORI-LP has a particle size of about (173 ± 12) nm. The particles exhibit a negative electrical charge (-31.5 ± 1.6 mV), and possess high encapsulation efficiency (94.1 ± 1.2%). There were significantly different parameters of k10 and area under the plasma concentration-time curve (AUC0-t) between liposomes and solution. The mean residence time (MRT0-t) in plasma of NOH-ORI-LP was 5.56 times longer than that of solution. Compared with solution, NOH-ORI-LP delivered about 4.28 times higher ORI into liver. Thus, an optimum intravenous galactose-modified liposome formulation for ORI could be developed as an alternative to the commercial ORI preparations.

[Preliminary study on brain-targeted drug delivery via inner ear].

The article investigates the feasibility of delivering drugs to brain via inner ear, and provides a novel route for delivering drugs to the brain tissues. Dexamethasone acetate (DA)-loaded solid lipid nanoparticles (SLN) was prepared by using Compritol 888 ATO as material. HPLC assays for the determination of DA, dexamethasone sodium phosphate (DSP) and dexamethasone (Dex) were developed, separately. DA-loaded SLN and DSP solution were administered after intratympanic injection (IT) or intravenous injection (IV). Perilymph ( PL) and cerebrospinal fluid (CSF) were collected periodically. The concentrations in PL and CSF were measured by HPLC, and used to estimate pharmacokinetic parameters of Dex in CSF. The AUC of Dex in CSF following IT DA-loaded SLN or DSP solution were respectively 2.5 and 4.3-fold higher than those following IV. After IT, DA-loaded SLN increased the AUC by 13 times and extended the MRT by 19 times, compared with the solution. Moreover, the AUC of Dex in PL following IT the SLN was 76% lower than that following IT the solution. Intra-cochlear administration shows great potential and offers a promising alternative to brain-targeted drug delivery.