METHOD: TQ-nanoparticles were prepared and optimized by using two different formulations with different drugs to PLGA-PEG ratio (1:20 and 1:7) and different PLGA-PEG to Pluronic F68 ratio (10:1 and 2:1). The morphology and size were determined using TEM and DLS. Characterization of particles was done using UV-VIS, ATR-IR, entrapment efficiency, and drug release. The effects of drug, polymer, and surfactants were compared between the two formulations. Cytotoxicity assay was performed using MTS assay.
RESULTS: TEM finding showed 96% of particles produced with 1:7 drug to PLGA-PEG were less than 90 nm in size and spherical in shape. This was confirmed with DLS which showed smaller particle size than those formed with 1:20 drug to PLGA-PEG ratio. Further analysis showed zeta potential was negatively charged which could facilitate cellular uptake as reported previously. In addition, PDI value was less than 0.1 in both formulations indicating monodispersed and less broad in size distribution. The absorption peak of PLGA-PEG-TQ-Nps was at 255 nm. The 1:7 drug to polymer formulation was selected for further analysis where the entrapment efficiency was 79.9% and in vitro drug release showed a maximum release of TQ of 50%. Cytotoxicity result showed IC50 of TQ-nanoparticle at 20.05 μM and free TQ was 8.25 μM.
CONCLUSION: This study showed that nanoparticle synthesized with 1:7 drug to PLGA-PEG ratio and 2:1 PLGA-PEG to Pluronic F68 formed nanoparticles with less than 100 nm and had spherical shape as confirmed with DLS. This could facilitate its transportation and absorption to reach its target. There was conserved TQ stability as exhibited slow release of this volatile oil. The TQ-nanoparticles showed selective cytotoxic effect toward UACC 732 cells compared to MCF-7 breast cancer cells.
OBJECTIVE: To investigate the evidence available: 1) on government initiatives to mandate transparency in drug pricing worldwide, 2) on the reported effects of drug pricing transparency initiatives on drug price, and 3) on the limitations and barriers of the implementation of drug pricing transparency.
METHODS: Databases such as Medline-Ovid, Cochrane Central Register, PubMed, and Science Direct were used to search for relevant literature from inception to February 2018. A manual search of grey literature such as policy papers, governmental publications, and websites was also performed to obtain the information that was not available in the articles. Using narrative synthesis, the results were critically assessed and summarized according to its context of drug pricing approaches.
RESULTS: Of the 4382 relevant articles located, 12 studies met the inclusion criteria for drug price transparency initiatives. Only 3 studies reported the outcomes on the regulation of drug prices. Two studies in South Africa showed that price transparency initiatives did not necessarily reduce drug prices. Another study in the Philippines indicated a reduction in medicines' price based on the effects of government-mediated access prices. The limitations and barriers in price transparency initiatives include fragmentation of the healthcare system and nondisclosure of discounts and rebates by pharmaceutical companies.
CONCLUSION: Drug pricing transparency initiatives have been implemented in many countries and commonly coexist with a country's pricing policies. Nevertheless, due to sparse evidence, the effect of drug price transparency initiatives on price control is still inconclusive.