Nano and microparticle engineering of water insoluble drugs using a novel spray-drying process

In the current study nano and microparticle engineering of water insoluble drugs was conducted using a novel piezoelectric spray-drying approach. Cyclosporin A (CyA) and dexamethasone (DEX) were encapsulated in biodegradable poly(d,l-lactide-co-glycolide) (PLGA) grades of different molecular weights. Spray-drying studies carried out with the Nano Spray Dryer B-90 employed with piezoelectric driven actuator. The processing parameters including inlet temperature, spray mesh diameter, sample flow rate, spray rate, applied pressure and sample concentration were examined in order to optimize the particle size and the obtained yield. The process parameters and the solute concentration showed a profound effect on the particle engineering and the obtained product yield. The produced powder presented consistent and reproducible spherical particles with narrow particle size distribution. Cyclosporin was found to be molecularly dispersed while dexamethasone was in crystalline state within the PLGA nanoparticles. Further evaluation revealed excellent drug loading, encapsulation efficiency and production yield. In vitro studies demonstrated sustained release patterns for the active substances. This novel spray-drying process proved to be efficient for nano and microparticle engineering of water insoluble active substances

Not Available

Not AvailableThe general phenylpropanoid metabolism generates an array of secondary metabolites and phenolicacids which imparts disease resistance in plants. Expression pattern of the key genes of phenylpropanoidpathway was studied at 0, 24 and 48 h after infection (h.a.i.) and phenolic acid profiling was carried outat 0, 24, 48 and 72 h.a.i. in the leaves of wilt infected and non- infected of both resistant and susceptiblegenotypes of castor. Expression analysis of PAL (phenylalanine ammonia lyase), C4H1 (cinnamate 4-hydroxylase 1) and C4H2 (cinnamate 4-hydroxylase 2) genes using RT-PCR with gene specific primersshowed appreciable increase in the expression of PAL and C4H-2 gene in resistant genotypes at 48 hinterval than 24 h interval compared to susceptible genotype. However, gene C4H-1 was down regulatedin susceptible genotypes after 24 and 48 h.a.i. while up regulated in resistant genotypes. Phenol profilingusing HPTLC showed the presence of three phenolic acids i.e. caffeic acid, ferulic acid and salicylic acidin non-infected and infected castor genotypes. Higher content of caffeic and ferulic acid was detected ininfected and non-infected resistant genotypes at 0, 24 and 48 h.a.i, whereas caffeic acid was not detectedin susceptible genotypes at 0 h.a.i. These results suggest the critical role of phenols in castor diseaseresistance.Not Availabl