full issue - Association of Biotechnology and Pharmacy

Current Trends in Biotechnology and PharmacyVol. 5 (2) 1110-1122 April 2011. ISSN 0973-8916 (Print), 2230-7303 (Online)1117emulsions. The formulations C4, C14 and C17did not show any kind of crystallinity whichsuggests that the drug molecules were inamorphous state. But in case of formulation C7two peaks appeared in right angles. This may bedue to the re-crystallization of the drug. Theresults were shown in Fig.3.Transmission electron microscopy:Transmission electron microscopic studies werecarried out for the formulation C14 to observethe physical properties of NE droplets.Transmission electron micrographs revealed thatthe droplets were spherical, homogeneous andno signs of precipitation. The droplet size wascorrelated with the results from particle sizeanalysis using zeta sizer. All these results werepresented in Fig.4.Pharmacokinetic studies: The plasmaconcentration vs time profiles of the carvedilolNE and carvedilol tablet suspension afteradministration of a single dose of 2.5mg/kg bodyweight were shown in Fig.5. The pharmacokinetic parameters were computed by noncompartmental analysis using winN onlinesoftware and the results were summarized in theTable 3. The NE was more effective in enhancingoral absorption and availability of carvedilol in theplasma. The average plasma concentrations ofcarvedilol were 70.07±8.90 and 39.59±5.78 after1 hour following oral administration of NE andtablet suspension respectively. Plasmaconcentration of carvedilol when administeredwith the NE remained higher than with the tabletsuspension for up to 6hrs. Significantly higherC max, AUC and AUMC values were observed incase of NE compared to tablet suspension. MRT,T maxand t 1/2values of carvedilol with NE werecomparable with that of oral tablet suspension.Mean T maxvalues were 0.5 hours in case of NEand 0.67±0.29 hours in case of tablet. There wasno significant difference in t 1/2.All these resultsFig.3. X-ray diffraction reports of standard drugCarvedilol and the nano emulsions (C4, C7, C14and C17) loaded with carvedilol.Fig.4. Transmission electron micrographs of the formulationC14 blank (A) and carvedilol loaded (B) nanoemulsions. The scale bar represents a distance of 500nmin Picture (A), 1000 nm in picture (B).revealed that the extent of oral absorption andbioavailability of carvedilol was significantlyincreased from oral nano emulsion compared withthe tablets.DiscussionSeveral drugs and dosage forms availablefor the treatment of hypertension, the mortalityKoteswari Poluri et al