Andrographolide Liquisolid using Porous-Starch as the Adsorbent with Enhanced Oral Bioavailability in Rats.

Andrographolide (AGL) is the major component of Andrographispaniculata. The poor water solubility and low dissolution strongly affect its oral absorption. Liquisolid technology has been used to improve its dissolution and oral bioavailability. Liquisolid powders of AGL (AGL-LS-PSG) were obtained by firstly dissolving AGL in the mixture of NMP, PEG 6000 and Soluplus®, and solidified by absorption of the blend in porous starch. Angle of repose, Carr index and Hauser ratio presented good powder fluidity and compressibility characteristics of AGL-LS-PSG. The results of optical microscopic observation, PXRD and DSC analysis indicated that AGL has been completely adsorbed in porous starch granules and existed in an amorphous or molecularly dispersing state. AGL-LS-PSG can obviously increase the drug dissolution rate compared to commercial guttate pills and raw drug. In vivo pharmacokinetic behavior of AGL-LS-PSG was investigated following a single oral administration to rats. The Cmax (0.37 ± 0.06 µg mL-1) and AUC0-2h (13.55 ± 2.67 µg h mL-1) of AGL-LS-PSG were evidently increased compared to commercial guttate pills (Cmax = 0.30 ± 0.21 µg mL-1, AUC0-2h = 9.88 ± 3.57 µg h mL-1). This study indicated great potential of liquisolid technology in effectively improving the dissolution and bioavailability of AGL.

Association of liver X receptor α (LXRα) gene polymorphism and ischemic stroke.

We examined the relationship between the liver X receptor a gene (LXRα) rsl2221497 polymorphism and the susceptibility to ischemic stroke in a Chinese population. The polymerase chain reaction-restriction fragment length polymorphism technique was used to detect the genotype of rsl2221497 in the LXRαgene of 300 stroke patients and 300 healthy control subjects. The chi-square test was used to analyze the genotype distribution between the 2 groups. We found that the risk of stroke in carriers with the AA + GA genotype was 2.12-fold higher than that in GG genotype carriers (odds ratio = 2.12, 95% confidence interval: 1.58-2.99, P < 0.05). The risk of stroke in carriers of the A allele increased by 1.03-fold compared to that in G allele carriers (odds ratio = 2.03, 95% confidence interval: 1.44-3.01, P < 0.01). After adjusting for other confounding factors such smoking, hypertension, and diabetes, the A allele was found to be an independent risk factor for stroke. Therefore, the rsl2221497 polymorphism in the LXRαgene was associated with the susceptibility to stroke in a Chinese population.

[Comparison between colorimetry and HPLC on the stability test of roxithromycin].

AIM: To compare the stability of roxithromycin in solutions of different pH. METHODS: Roxithromycin solutions of different pH were prepared with water, simulate intestinal fluid (SIF) and simulate gastric fluid (SGF) shown to be the stability of these solutions were tested by colorimetry and HPLC. RESULTS: Roxithromycin was stable in water, SGF and SIF determined by colorimetry. However, it was found to be stable only in water and SIF but unstable in SGF as determined by HPLC. CONCLUSION: Roxithromycin is unstable in acidic medium like SGF. The metabolite of roxithromycin showed unfavorable interference on the assay of roxithromycin when colorimetry was used. Colorimetry can not be used for the determination and assay of roxithromycin in acidic solution like SGF.

Identification of base substitutions in the promoter regions of the A gamma- and G gamma-globin genes in A gamma- (or G gamma-) beta+-HPFH heterozygotes using the DNA-amplification-synthetic oligonucleotide procedure.

DNA amplification combined with hybridization with 32P-labeled synthetic oligonucleotide probes has been used to identify base substitutions in the 5' promoter region of the A gamma globin gene in members of eleven families from China, Sardinia, Canada, and the United States who had a heterozygosity for the A gamma-beta+-hereditary persistence of fetal hemoglobin (HPFH), and in members of six black families with a possible G gamma-beta+-HPFH heterozygosity. All three known A gamma types were observed, ie, the British type (-198, T----C), the Chinese type (-196, C----T), and the Green type (-117, G----A); the latter has been found in a black family. Of the six families with G gamma-beta+-HPFH, three had C----G at -202 and none T----C -175. Conditions for hybridization of amplified DNA with the specific probes are provided and the usefulness of the technique is discussed. The increase in numbers of A gamma(G gamma)-beta+-HPFH heterozygotes with specific base substitutions greatly enhances the probability of a direct correlation between these substitutions and the increase in the production of a specific gamma chain.