Nanoparticle loading Sample Clauses

Nanoparticle loading. For lipid shell nanoparticles, rifampicin was incorporated into the carriers by addition to the triglyceride phase as a 0.5% w/v acetonic solution. The acetone was removed by evaporation before continuing with the manufacture protocol. In order to try and enhance the interaction between rifampicin and oil, two counterions, sodium stearateand sodium ethyl acetate were combined with rifampicin at the molar ratio of 1:20 during the manufacture.For the fabrication of drug loaded PVA shell nanoparticles, 15 mg of rifampicin was dissolved in the organic phase and the manufacture was repeated as optimised previously. Amicon centrifugal device was used for loading assessment. The amount of each probe contained in a) the purified suspension as a whole, b) the nanoparticles only and c) the continuous phase was assayed by appropriate dilution of each compartment. The nanoparticles were separated from the continuous phase using Amicon ultra 0.5 centrifugal filter devices with ultracel 100 membranes (100 kDa molecular weight cut off) (Millipore, UK). Aliquots of 0.5 mL were removed from the purified nanoparticle suspension and placed in the sample reservoir of the filter devices and centrifuged for 30 min at 14,000 g at ambient temperature (Biofuge Pico centrifuge, Heraeus, Buckinghamshire, UK). During this process any free drug in the continuous phase passed through the filter into the receiver chamber, and the nanoparticles were retained on the filter. The filtrate was diluted with water and subjected to HPLC analysis. The nanoparticles were dissolved in methanol and subjected to HPLC analysis. The drug recovery and loading efficiency of the purified nanosuspensions were calculatedusing Equations 2.1 and 2.2, respectively: Drug recovery = Mnanoparticle + Mfiltrate Msuspension Loading efficiency (%) = Mnanoparticle Minput Equation 2.1 Equation 2.2 Where Msuspension was the mass of drug in the nanoparticle suspension; Mnanoparticle was the mass of drug encapsulated into the nanoparticle; Mfiltrate was the mass of drug in aqueous filtrate and Minput was the mass of drug added during manufacture.