Near infrared reflectance spectroscopy for the fast identification of PVC-based films.

Near infrared (NIR) reflectance spectroscopy was used to develop a non-destructive and rapid qualitative method for the analysis of plastic films used by the pharmaceutical industry for blistering. Three types of films were investigated: 250 microm PVC [poly(vinyl chloride)] films, 250 microm PVC films coated with 40 g m(-2) of PVDC [poly(vinylidene dichloride)] and 250 microm PVC films coated with 5 g m(-2) of TE (Thermoelast) and 90 g m(-2) of PVDC. Three analyses were carried out using different pre-treatment options and a PLS (partial least squares) algorithm. Each analysis was aimed at identifying one type of film and rejecting all types of false sample (different thickness, colour or layer). True and false samples from four plastics manufacturers were included in the calibration sets in order to obtain robust methods that were suitable regardless of the supplier. Specificity was demonstrated by testing validation sets against the methods. The tests showed 0% of type I (false negative identification) and 1% of type II errors (false positive identification) for the PVC method, 13 and 3%, respectively, for the PVC-PVDC method and no error for the PVC-TE-PVDC method. Type II errors, mostly due to the slight sensitivity of the methods to film thickness, are easily corrected by simple thickness measurements. This study demonstrates that NIR spectroscopy is an excellent tool for the identification of PVC-based films. The three methods can be used by the pharmaceutical industry or plastics manufacturers for the quality control of films used in blister packaging.

Manufacture of polyalkylcyanoacrylate nanoparticles with pilocarpine and timolol by micelle polymerization: factors influencing particle formation.

Nanoparticles with pilocarpine and timolol were produced by micelle polymerization. The influence of manufacturing temperature, type of monomer, drug concentration and ethylcyanoacrylate concentration on the particle size were investigated with a Coulter Nano Sizer. The nanoencapsulation succeeded only with the pilocarpine or timolol base, not with the salts of these drugs. Different micelle formation in aqueous medium compared with organic solvents was evidently responsible for this phenomenon. The particle formation was affected both by the manufacturing temperature and the type of monomer. The smallest particles were produced at lower temperatures and with the most lipophilic monomers. The monomer and drug concentration had very little influence on the particle size. The nanoparticles made with pilocarpine were, in general, much bigger than those made with timolol.