The pulmonary route of delivery offers a potential alternative to parenteral administration of peptides and proteins. Protection of protein structure is essential in both processing and storage of the final formulation. Sugars, such as trehalose and raffinose, have been employed to act as protein stabilisers. Optimisation of the aerodynamic characteristics of microparticles in dry powder inhaler formulations is critical to ensure optimum deposition of the formulation into the respiratory tract. In the present study we examine the adaptation to hydrophilic materials, specifically the disaccharide, trehalose and the trisaccharide, raffinose, of a previously reported spray drying process for producing nanoporous microparticles (NPMPs). We also investigate the feasibility of incorporating a model protein, lysozyme, into these sugar-based NPMPs. While spray drying raffinose or trehalose from aqueous solution or ethanol:water solutions resulted in non-porous microspheres, spray drying from a methanol:n-butyl acetate mixed solvent system resulted in microparticles which appeared to consist of an agglomeration of individual nanoparticles, i.e. nanoporous/nanoparticulate microparticles. NPMPs of trehalose and raffinose were amorphous, with glass transition temperatures (Tgs) that were sufficiently high (124°C and ∼120°C for trehalose and raffinose, respectively) to suggest good physical stability at room temperature and good potential to act as protein carriers and/or stabilisers. NPMPs demonstrated improved aerosolisation properties compared to spray dried non-porous particles. The successful incorporation of lysozyme into these NPMPs at a sugar to protein weight ratio of 1:4 demonstrated the potential of these systems to act as carriers for peptide or protein drugs which could be delivered via the pulmonary route.
IntroductionLung cancer, the most prevalent malignant cancer in the world, remains a serious threat to public health. Recently, a large number of studies have shown that an epidermoid growth factor receptor-tyrosine kinase inhibitor (EGFR TKI), Erlotinib, has significantly better efficacy and is better tolerated in advanced non-small cell lung cancer (NSCLC) patients with a positive EGFR gene mutation. However, access to this drug is severely limited in China due to its high acquisition cost. Therefore, we decided to conduct a study to compare cost-effectiveness between erlotinib monotherapy and carboplatin-gemcitabine (CG) combination therapy in patients with advanced EGFR mutation-positive NSCLC.MethodsA Markov model was developed from the perspective of the Chinese health care system to evaluate the cost-effectiveness of the two treatment strategies; this model was based on data from the OPTIMAL trial, which was undertaken at 22 centres in China. The 10-year quality-adjusted life years (QALYs), direct costs, and incremental cost-effectiveness ratio (ICER) were estimated. To allow for uncertainties within the parameters and to estimate the model robustness, one-way sensitivity analysis and probabilistic sensitivity analysis were performed.ResultsThe median progression-free survival (PFS) obtained from Markov model was 13.2 months (13.1 months was reported in the trial) in the erlotinib group while and 4.64 months (4.6 months was reported in the trial) in the CG group. The QALYs were 1.4 years in the erlotinib group and 1.96 years in the CG group, indicating difference of 0.56 years. The ICER was most sensitive to the health utility of DP ranged from $58,584.57 to $336,404.2. At a threshold of $96,884, erlotinib had a 50%probability of being cost-effective.ConclusionsErlotinib monotherapy is more cost-effective compared with platinum-based doublets chemotherapy as a first-line therapy for advanced EGFR mutation- positive NSCLC patients from within the Chinese health care system.
For patients in China with resectable disease, our results suggest that adjuvant chemotherapy with capecitabine plus oxaliplatin after a D2 gastrectomy is cost-saving and dominant in the long run on the basis of a current clinical trial, compared with treatment with a D2 gastrectomy alone.
Sodium cromoglicate is an antiasthmatic and antiallergenic drug used in inhalation therapy and commonly administered by a dry powder inhaler.In the present study we sought to examine the feasibility of producing nanoporous microparticles (NPMPs) of this hydrophilic material by adaptation of a spray drying process previously applied to hydrophobic drugs, and to examine the physicochemical and in vitro deposition properties of the spray dried particles in comparison to a commercial product. The storage stability of successfully prepared NPMPs was assessed under a number of conditions Spray dried sodium cromoglicate was amorphous in nature. NPMPs of sodium cromoglicate displayed superior aerodynamic properties resulting in improved in vitro drug deposition, as assessed by Andersen Cascade Impactor and twin impinger studies, in comparison to the commercial product, Intal ® . Deposition studies indicated that porosity and sphericity were important factors in improving deposition properties. The optimum solvent system for NPMP production was water:methanol:n-butyl acetate, as spherical NPMPs spray dried from this solvent system had a higher respirable fraction than non-spherical NPMPs of sodium cromoglicate (spray dried from methanol:n-butyl acetate), non-porous sodium cromoglicate (spray dried from water) and micronised sodium cromoglicate (Intal ® ).While particle morphology was altered by storage at high humidity (60% RH) and in vitro deposition performance deteriorated, it was possible to maintain NPMP morphology and aerosolisation performance by storing the powder with dessicant.
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