The Class F fly ash has been subjected to high energy ball milling and has been converted into nanostructured material. The nano structured fly ash has been characterized for its particle size by using particle size analyzer, specific surface area with the help of BET surface area apparatus, structure by X-ray diffraction studies and FTIR, SEM and TEM have been used to study particle aggregation and shape of the particles. On ball milling, the particle size got reduced from 60 lm to 148 nm by 405 times and the surface area increased from 0.249 m 2 /gm to 25.53 m 2 /gm i.e. by more than 100%. Measurement of surface free energy as well as work of adhesion found that it increased with increased duration of ball milling. The crystallite was reduced from 36.22 nm to 23.01 nm for quartz and from 33.72 nm to 16.38 nm for mullite during ball milling to 60 h. % crystallinity reduced from 35% to 16% during 60 h of ball milling because of destruction of quartz and hematite crystals and the nano structured fly ash is found to be more amorphous. Surface of the nano structured fly ash has become more active as is evident from the FTIR studies. Morphological studies revealed that the surface of the nano structured fly ash is more uneven and rough and shape is irregular, as compared to fresh fly ash which are mostly spherical in shape.
The purpose of this study was to evaluate the influence of chemically modified beta-cyclodextrin (beta-CD) which could affect the in-vivo stabilization of liposomal preparation derived from proliposome entrapping inclusion complex of amphotericin B (AmB) with beta-CD. A series of liposomal AmB formulations with varying beta-CD i.e. Hydroxypropyl beta-CD (HPBCD) & Sulfo butyl ether beta-CD (SBEBCD) and lipid dose having similar AmB content (0.5 mg/kg) were compared with conventional liposomal amphotericin B (L-AmB) or free AmB in rats and their pharmacokinetic data were analyzed considering the varying volume of distribution with respect to the varying lipid concentration (65mg to 110mg) in blood. These results indicate that L-AmB entrapped inclusion complexes safely achieved higher Cmax (P < 0.05) & AUC (P < 0.02) and demonstrated saturable, nonlinear elimination from plasma via reticuloendothelial organ uptake at higher lipid level (>80mg) as compared with conventional L-AmB or free AmB. Furthermore in-vivo stabilization potential for liposomal preparation via AmB/ beta-Cyclodextrin inclusion complexes appeared to be in pattern of HPBCD < SBEBCD. It is concluded that the preparation of liposome derived from proliposome entrapping inclusion complex of amphotericinB (AmB) with beta-CD could serve an alternative approach to enhance the therapeutic window of AmB in clinical medicine.
The purpose of this research was to develop a novel hydroalcoholic method for the preparation of liposome entrapping inclusion complex of amphotericin B (AmB) with a view to obtaining reduced toxicity and superior tissue distribution of AmB in vivo. The method involves initial preparation of AmB-hydroxypropyl-beta-cyclodextrin (AmB-HPBCD) intercalated proliposome which is subsequently converted into a liposome dispersion by single dilution method. The AmB-liposome (L-AmB) derived from proliposome exhibited a superior entrapment efficiency (94.8 +/- 0.7%) compared to liposomes prepared by employing a conventional solvent-based technique (89.7 +/- 2.9%). The dose that was lethal to 50% of subjects (LD50) (mg/kg) value of AmB contained in stabilized proliposome-based liposomes was 18.6 +/- 0.25, whereas that in conventional solvent-based liposomes was 7.8 +/- 0.25. Incorporation of AmB-HPBCD into hydroalcoholic liposomes enhanced antifungal activity in experimental aspergillosis in Balb/c mice in vivo: 80% survival was recorded after 7 days of therapy and the fungal load in lung was reduced. The results clearly demonstrate that preferential uptake of L-AmB entrapped inclusion complex (AmB-HPBCD) by the reticulo endothelial system correlated with diminished levels of AmB in infected (p > 0.05) and noninfected (p > 0.001) kidney after 24 hr compared to that observed with conventional solvent-based L-AmB. Therefore, proliposome-based liposome entrapping inclusion complex of AmB with HPBCD offered an improved therapeutic efficacy by lowering toxicity as well as by altering the tissue distribution pattern.
HA-1-92, a new polyene oxohexaene macrolide antibiotic isolated from Streptomyces CDRIL-312, was incorporated into liposomes containing phosphotidyl choline and cholesterol. The liposomal incorporated HA-1-92 considerably decreased toxicity when compared with free HA-1-92 in mice. Liposomal HA-1-92 showed improved pharmacokinetic profiles in rats. When administered to aspergillosis- and cryptococcosis-infected Balb/c mice, liposomal HA-1-92 showed increased antifungal activity, compared with free HA-1-92, with improved survival rate and decreased colony-forming units in lung, liver, spleen and kidney. These results suggest that liposomal HA-1-92 is more effective than free HA-1-92 in controlling experimental aspergillosis and cryptococcosis in Ba1b/c mice.
Stability studies of some novel dual action fluoroquinolonyl-3′ ′ ′ ′ ′-penicillin amides (1a-e) in aqueous DMF (1:1) solution has been carried out in presence of Cu (ic) or Hg (ic) ions and their degradation rate was monitored by UV/Vis spectrophotometric method. The results thus obtained indicate that ciprofloxacin moiety offered greater stability to the ß-lactam moiety of the hybrid (1d or 1e) than norfloxacin (1a or 1b) in the presence of heavy metal ion degradation; whereas the degradation pattern of ß-lactam moiety in the hybrids under investigation (1a-e) was found to be in agreement with the previously reported heavy metal ion degradation profile of the penicillins.
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