Leukemia and rosiglitazone

Cytarabine chemotherapy induces meibomian gland dysfunction

PURPOSE

Cytarabine (Ara-C) chemotherapy causes symptoms resembling meibomian gland dysfunction (MGD), suggesting potential associations between Ara-C and MGD. In this study, the pathological effects of Ara-C on MGD were investigated in a rodent model.

METHODS

Mice received Ara-C with or without rosiglitazone (PPARγ agonist) for 7 consecutive days. Slit-lamp biomicroscope was used for ocular examinations. Immunofluorescence detected acinar cell proliferation, differentiation, and ductal keratinization in the meibomian gland (MG). Lipid accumulation was evaluated by Oil Red O and LipidTox staining. Lipogenic status, FoxO1/FoxO3a cellular localization, and oxidative stress were visualized via immunohistochemistry. Western blotting assessed relative protein expression and AKT/FoxO1/FoxO3a pathway phosphorylation.

RESULTS

Ara-C (50 mg/kg) did not affect mouse survival but induced damage to ocular surface microenvironment, including corneal epithelial defects, MG orifice plugging and acinar dropout, and lacrimal gland (LG) dysfunction. Ara-C intervention inhibited proliferation and caused progenitor loss in the MG, as evidenced by reduced PCNA + labeling and P63+/Lrig1+ basal cell numbers. The MG ducts of Ara-C-treated mice exhibited marked dilatation, lipid deposition, and hyperkeratinization (K1/K10 overexpression). Ara-C disrupted MG lipid metabolism by downregulating PPARγ and its downstream lipogenic targets AWAT2/SOAT1/ELOVL4 and upregulating HMGCR. Dephosphorylation of AKT and the subsequent nuclear translocation of FoxO1/FoxO3a contributed to Ara-C-induced PPARγ downregulation. Ara-C triggered oxidative stress with increases in 4-HNE and 8-OHdG and Keap1/Nrf2/HO-1/SOD1 axis dysregulation. Rosiglitazone treatment ameliorated MGD-associated pathological manifestations, LG function, MG lipid metabolism, and oxidative stress in Ara-C-exposed mice.

CONCLUSIONS

Systemic Ara-C chemotherapy exerted topical cytotoxic effects on the ocular surface, and PPARγ restoration by rosiglitazone mitigated Ara-C-induced MGD alterations.

A Cost Effective (QbD) Approach in the Development and Optimization of Rosiglitazone Maleate Mucoadhesive Extended Release Tablets -In Vitro and Ex Vivo

Purpose: The purpose of the study was to develop and optimize rosiglitazone maleate mucoadhesive extended-release tablets by quality by design (QbD) approach. Based on QTPP (quality target product profile) CQAs (critical quality attributes) were identified.

Methods: Failure mode and effects analysis (FMEA) method were adopted for risk assessment. Risk analysis by the evaluation of formulation and process parameters showed that the optimizing the levels of polymers could reduce high risk to achieve target profile. Drug-excipient compatibility studies by Fourier transforms infra-red and DSC studies showed that the drug was compatible with the polymers used. Design of experiment (DoE) performed by Sigma tech software, Carbopol 934P and sodium carboxymethyl cellulose (SCMC) were identified as independent variables and hardness, drug release at 12 hours and ex vivo mucoadhesion time were adopted as responses. Contour plots generated from the software were used for identification of design space.

Results: Carbopol 934P and SCMC had positive and negative effects respectively on the selected responses. Higher the concentration of Carbopol 934P and lower the concentration of SCMC mucoadhesive extended release criteria could be achieved. Drug release kinetics followed first order release with Higuchi diffusion and Fickian diffusion. Ex vivo mucoadhesion test on goat stomach mucosa indicated that adhesion time increased at higher concentrations of Carbopol 934P. Optimized formula satisfying all the required parameters was selected and evaluated. The predicted response values were in close agreement with experimental response values, confirmed by calculating standard error.

Conclusion: It has been concluded that the application of QbD in the optimization reduced the number of trials to produce a cost-effective formula.