1.Silymarin-laden PVP-PEG polymeric composite for enhanced aqueous solubility and dissolution rate: Preparation and in vitro characterization
Yousaf Mehmood ABID ; Malik Rashid USMAN ; Shahzad YASSER ; Mahmood TARIQ ; Hussain TALIB
Journal of Pharmaceutical Analysis 2019;9(1):34-39
The aim of this work was to develop, optimize and characterize a silymarin-laden polyvinylpyrrolidone (PVP)-polyethylene glycol (PEG) polymeric composite to resolve low aqueous solubility and dissolution rate problem of the drug. A number of silymarin-laden polymeric formulations were fabricated with different quantities of PVP K-30 and PEG 6000 by the solvent-evaporation method. The effect of PVP K-30 and PEG 6000 on the aqueous solubility and dissolution rate was investigated. The optimized formula-tion and its constituents were characterized using powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) techniques. Both the PEG 6000 and PVP K-30 positively affected the aqueous solubility and dis-solution rate of the drug. In particular, a formulation consisting of silymarin, PVP K-30 and PEG 6000 (0.25/1.5/1.5, w/w/w) furnished the highest solubility (24.3972.95 mg/mL) and an excellent dissolution profile (~100% in 40 min). The solubility enhancement with this formulation was ~1150-fold as com-pared to plain silymarin powder. Moreover, all the constituents existed in the amorphous state in this silymarin-laden PVP-PEG polymeric composite. Accordingly, this formulation might be a promising tool to administer silymarin with an enhanced effect via the oral route.
2.Validation of arrhythmogenic right ventricular cardiomyopathy risk calculator for sudden cardiac death: a systematic review
Sarim RASHID ; Ritesh PAHWANI ; Sahil RAJ ; Hafiz Ahmed Raza KHAN ; Saffa NADEEM ; Muhammad Usman GHANI ; Jawad BASIT ; Amin MEHMOODI ; Jahanzeb MALIK
International Journal of Arrhythmia 2023;24(4):25-
In the context of ARVC, a systematic review of the validation of the ARVC risk score can provide insights into the accuracy and reliability of this score in identifying patients at high risk of ARVC. Digital databases were searched to identify the relevant studies using Medical Subject Headings (MeSH). A total of 8 studies were included in this systematic review. A total of 8 studies were included in this review. The review found that the sensitivity of the ARVC risk scores ranged from 80 to 95%, and the specificity ranged from 31 to 79%. The PPV was 55%, and the NPV was 88%. The ARVC score provided a C-index for a 5-year VA risk prediction of 0.84 [95% CI (0.74–0.93)] and a Harrell C-index of 0.70 (95% CI 0.65–0.75). The calibration slope was 1.01 (95% CI 0.99–1.03). ARVC score demonstrated a significant event 5-year threshold between 15 and 20% and the classical ARVC 5-years/freedom-from-VA rate was 0.76(0.66–0.89) and the non-classical form 5-years/freedom-from-VA rate was 0.58 (0.43–0.78). In conclusion, the validation of ARVC risk scores is an essential step toward improving the accuracy of ARVC diagnosis and risk stratification. Further studies are needed to establish the accuracy and reliability of ARVC risk scores and to address the limitations of the current evidence.