Bioequivalence Studies of Sildenafil Citrate Orodispersible Film Administered with and without Water vs ViagraⓇ Film-Coated Tablets in Healthy Male Volunteers.

Background: Orodispersible film (ODF) formulation offers ease of use, convenience of administration, and other advantages, especially for patients who have difficulty in swallowing or are on liquid restriction compared with conventional oral formulations for the treatment of erectile dysfunction. Objectives: These studies compared the bioequivalence of 50 mg sildenafil citrate ODF formulation (test drug) with the marketed 50 mg sildenafil citrate film-coated tablet (FCT) (ViagraⓇ; Pfizer, New York, NY) (reference drug), with and without water in 2 randomized cross-over studies. Methods: Two randomized cross-over studies were conducted. The first study explored the bioequivalence of test drug administered with and without water compared with the reference drug with water. The second study investigated the bioequivalence of test drug, without water, compared with the reference drug with water. Forty-two and 80 healthy male volunteers were recruited in the first and second study, respectively. All volunteers fasted for 10 hours pre-dose. A 1-day washout period between doses was observed. Blood samples were collected at both before (up to 120 minutes before dosing) and after dosing (at different intervals up to 14 hours) stages. Statistical analyses on pharmacokinetic parameters were performed. Safety and tolerability for both the formulations were evaluated. Results: In the first study, bioequivalence was demonstrated for sildenafil citrate ODF administered with water when compared with the ViagraⓇ FCT. The ratios of adjusted geometric means (90% confidence interval (CI)) were maximum plasma concentration: 1.02 (94.91-108.78) and area under the plasma concentration-time curve: 1.09 (104.49-113.21) for sildenafil citrate ODF administered with water vs ViagraⓇ FCT. These ratios were within the bioequivalence acceptance range of 80% to 125%, indicating that the bioequivalence criteria were met. The pharmacokinetic parameters for the second study also showed bioequivalence for sildenafil citrate ODF (without water) compared with ViagraⓇ FCT. The ratios of adjusted geometric means (90% CI) were maximum plasma concentration: 1.02 (95.47-109.36) and area under the plasma concentration-time curve: 1.06 (103.42-108.40) for sildenafil citrate ODF administered without water vs ViagraⓇ FCT. Adverse events in both the studies occurred at similar rates for the 2 formulations and were mild in intensity. Conclusions: These results suggest that the new ODF formulation can be used interchangeably with the marketed FCT formulation. Sildenafil citrate ODF administered with and without water met bioequivalence criteria compared with ViagraⓇ FCT administered with water under fasted conditions in healthy adult male volunteers. The new ODF formulation can be used as a suitable alternative to the conventional oral solid dosage form.

Phosphorylation of EphA2 receptor and vasculogenic mimicry is an indicator of poor prognosis in invasive carcinoma of the breast.

PURPOSE: The occurrence of vasculogenic mimicry (VM) and EphA2-mediated tumour progression are associated with poor prognosis in various solid tumours. Here, we aimed to investigate the prognostic implications of VM and its association with phosphorylated EphA2 receptor in invasive carcinoma of the breast. METHODS: The patients were stratified based on CD-31/PAS dual staining and subsequently the expression status of phospho-EphA2 (S897), FAK, phospho-ERK1/2 and Laminin 5Ƴ2 was analysed by immunohistochemistry. Survival of patients was correlated within the stratified cohort. RESULTS: The pathologically defined VM phenotype and phospho-EphA2 (S897) expression status were significantly associated with lower disease-free survival (DFS) and overall survival (OS). Both the features were also found to be significantly associated with higher nodal status, poor Nottingham Prognostic Index (NPI) and were more prevalent in the triple-negative breast cancer (TNBC) group. Incidentally, there were no significant association between age of the patient, grade and size of the tumour with VM and phospho-EphA2 (S897). The effector molecules of phospho-EphA2 (S897) viz., Focal Adhesion Kinase (FAK), phospho-ERK1/2 and Laminin 5Ƴ2 were significantly upregulated in the VM-positive cohort. Survival analysis revealed that the VM and phospho-EphA2 (S897) dual-positive cohort had poorest DFS [mean time = 48.313 (39.992-56.633) months] and OS [mean time = 56.692 (49.055-64.328) months]. Individually, VM-positive [Hazard Ratio (HR) 6.005; 95% confidence interval (CI) 2.002-18.018; P = 0.001 for DFS and HR 11.654; 95% CI 3.195-42.508; P < 0.0001 for OS] and phospho-EphA2 (S897)-positive (HR 4.342; 95% CI 1.717-10.983; P = 0.002 for DFS and HR 5.853; 95% CI 1.663-20.602; P = 0.006 for OS) expression proved to be independent indicators of prognosis. CONCLUSION: This study evaluated tumour dependency on oncogenic EphA2 receptor regulation and VM in invasive carcinoma of the breast and their prognostic significance. Significant correlations between VM, phospho-EphA2 and several clinicopathologic parameters of breast cancer were found. Subsequently, the occurrence of VM or phospho-EphA2 expression proved to be major contributors for poor prognosis in patients with breast cancer but their simultaneous expression failed to be an independent risk factor.