The objective of this study was to develop an ocular drug delivery system built on the cationic liposomes, a novel bioadhesive colloidal system, which could enhance the precorneal residence time, ocular permeation, and bioavailability of ibuprofen. The optimal formulation of cationic liposomes prepared by ethanol injection method was ultimately confirmed by an orthogonal L (3) test design. In addition, γ-scintigraphic technology and the microdialysis technique were utilized in the assessment of in vivo precorneal retention capability and ocular bioavailability individually. In the end, we acquired the optimal formulation of ibuprofen cationic liposomes (Ibu-CL) by orthogonal test design, and the particle size and entrapment efficiency (EE%) were 121.0 ± 3.5 nm and 72.9 ± 3.4%, respectively. In comparison to ibuprofen eye drops (Ibu-ED), Ibu-CL could significantly prolong the T to 100 min and the AUC to 1.53-folds, which indicated that the Ibu-CL could improve the precorneal retention time and bioavailability of ibuprofen. Consequently, these outcomes designated that the ibuprofen cationic liposomes we researched probably are a promising application in ocular drug delivery system.

ObjectiveAmyloid-β positron emission tomography (Aβ-PET) scan has been proposed to detect amyloid-β (Aβ) deposition in the brain. However, this approach is costly and not ideal for the early diagnosis of Alzheimer’s disease. Blood-based Aβ measurement offers a scalable alternative to the costly or invasive biomarkers. The aim of this study was to statistically validate whether plasma Aβ could predict Aβ-PET status via meta-analysis.MethodsWe systematically searched for eligible studies from PubMed, Embase and Cochrane Library, which reported plasma Aβ levels of amyloid-β positron emission tomography-positive (PET (+)) and amyloid-β positron emission tomography-negative (PET (−)) subjects. We generated pooled estimates using random effects meta-analyses. For any study that has significant heterogeneity, metaregression and subgroup analysis were further conducted. Publication bias was appraised by funnel plots and Egger’s test.Results16 studies with 3047 participants were included in the meta-analysis. Among all the enrolled studies, 10 studies reported plasma Aβ40 values, while 9 studies reported plasma Aβ42 values and 13 studies reported Aβ42/Aβ40 ratio. The pooled standardised mean difference (SMD) was 0.76 (95% CI −0.61 to 2.14, p=0.28) in the plasma Aβ40 values group. Plasma Aβ42 values group has a pooled SMD of −0.60 (95% CI −0.80 to −0.41, p<0.0001). In the plasma Aβ42/Aβ40 ratio group, the pooled SMD was −1.44 (95% CI −2.17 to −0.72, p<0.0001).ConclusionPlasma Aβ40 values might not distinguish between PET (+) and PET (−) people. However, plasma Aβ42 values and plasma Aβ42/Aβ40 ratio could be served as independent biomarkers for predicting Aβ-PET status.

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The objective of this study was to investigate the fundamental properties of propranolol hydrochloride osmotic pump tablets coated by aqueous polymer dispersion, simultaneously exploring the in vitro and in vivo correlation of the tablet. The physicochemical properties and parameters of aqueous polymer dispersion membranes (SEM, water uptake, and water vapor transmission coefficient) were investigated. In addition, the release behavior and the in vitro release and in vivo absorption profiles of the tablets coated by aqueous polymer dispersion were investigated by comparing with propranolol hydrochloride osmotic pump tablets coated by an organic solvent. Results showed that the similarity factor (f ) between cellulose acetate-coated tablet and Eudragit-coated tablet was 78.1, and f between cellulose acetate-coated tablet and Kollicoat-coated tablet was 77.6. The linear IVIVC of Eudragit-coated and Kollicoat-coated osmotic pump tablets was determined, which confirmed excellent correlation between the absorption in vivo and the drug release in vitro. Consequently, the membrane coated by aqueous polymer dispersion or organic solvent has similar in vitro release rates of controlled release. Also, compared with organic solvent coating, aqueous polymer dispersion has numerous advantages, such as reduced toxicity and no environmental damage. Therefore, the aqueous polymer dispersion technology has enormous potential as a replacement of organic solvent coating.

The objective of this study was to develop an authentic ionic-driven osmotic pump system and investigate the release mechanism, simultaneously exploring the in vitro and in vivo correlation of the ionic-driven osmotic pump tablet. A comparison of the ionic-driven and conventional theophylline osmotic pump, the influence of pH and the amount of sodium chloride on drug release, the relationship between the ionic osmotic pressure and the drug release, and the pharmacokinetics experiment in beagle dogs were investigated. Consequently, the similarity factor (f ) between the novel and conventional theophylline osmotic pump tablet was 60.18, which indicated a similar drug-release behavior. Also, the release profile fitted a zero-order kinetic model. The relative bioavailability of the ionic-driven osmotic pump to the conventional osmotic pump calculated from the AUC was 93.6% and the coefficient (R = 0.9945) confirmed that the ionic-driven osmotic pump exhibited excellent IVIVC. The driving power of the ionic-driven osmotic pump was produced only by ions, which was strongly dependent on the ion strength, and a novel formula for the ionic-driven osmotic pump was derived which indicated that the drug-release rate was proportional to the ionic osmotic pressure and the sodium chloride concentration. Significantly, the formula can predict the drug-release rate and release characteristics of theophylline ionic-driven osmotic pumps, guiding future modification of the ionic osmotic pump.

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