This paper investigates Raman spectroscopy as a quick and reliable method to quantify the alpha (α) and gamma (γ) polymorphic forms of indomethacin compared to differential scanning calorimetry (DSC). Binary mixtures with different ratios of α and γ indomethacin were prepared and analyzed by Raman and DSC. The Raman method was found to be more reliable and superior compared to DSC. The partial conversion of the alpha to gamma polymorphic form during the DSC measurement was the major limitation for the use of full DSC as a quantitative method and resulted in difference between the calculated and measured enthalpy of both polymorphic forms.
We report a successful formulation of Artemisone (ATM) in transferrin (Tf)-conjugated nanostructured lipid carriers (NLCs), achieving nearly a five-times increase in cell toxicity. The escalating cost of new drug discoveries led to the repurposing of approved drugs for new indications. This study incorporated Artemisone, an antimalarial drug, into a nanostructured lipid carrier (NLC) and tested for possible anticancer effects. The aim was to develop NLCs, and transferrin-conjugated NLCs (NLC-Tf) encapsulating Artemisone to enhance its delivery and anticancer activity. NLC formulations were prepared using high-pressure homogenization followed by ultrasonication and were characterized by particle size, zeta potential, and PDI. The conjugation of (Tf) to (NLC) was confirmed using IR, and the anticancer activity was tested using MTS assay. All formulations were in the nanometer size range (140–167 nm) with different zeta potential values. IR spectroscopy confirmed the successful conjugation of transferrin to NLC. Upon testing the formulations on melanoma cell lines using MTS assay, there was a significant decrease in viability and an increase in the encapsulated ATM-Tf toxicity compared to positive control ATM. The NLCs presented a promising potential carrier for delivering ATM to melanoma cells, and further conjugation with Tf significantly improved the ATM cytotoxicity.
Background: We report the successful formulation of a bone-targeted vancomycin-loaded liposomal carrier. Method: The basic liposomal structure is composed of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), cholesterol, and dicetyl phosphate (DCP) in a molar ratio of 3:1:0.25, respectively. The dehydration–rehydration method was used to maximize the liposomal-encapsulation efficiency of vancomycin after the initial preparation using thin-film hydration. Results: Sodium alendronate was used as a targeting moiety and was successfully conjugated to DSPE–PEG–COOH via carbodiimide chemistry, as was confirmed using IR spectroscopy. The resulting conjugate, DSPE–PEG-alendronate, was subsequently used in the formulation of bone-targeting vancomycin-loaded liposomes. In vitro binding assays with hydroxyapatite demonstrated preferential binding of the surface-modified liposomes to hydroxyapatite crystals. Furthermore, ex vivo studies revealed that the surface-modified liposomes exhibited enhanced binding affinity to the tibial bone tissue of 4-week-old male CD1 mice, in comparison to unmodified liposomes. Conclusions: The successfully formulated surface-modified vancomycin loaded liposomes showed enhanced bone affinity with a great potential for targeting the antibiotic to infected bones.
Cystic fibrosis (CF) is a rare genetic disorder commonly affecting multiple organs such as the lungs, pancreas, liver, kidney, and intestine. Our search focuses on the pathophysiological changes that affect the drugs’ absorption, distribution, metabolism, and excretion (ADME). This review aims to identify the ADME data that compares the pharmacokinetics (PK) of different drugs in CF and healthy subjects. The published data highlight multiple factors that affect absorption, such as the bile salt precipitation and the gastrointestinal pH. Changes in CF patients’ protein binding and body composition affected the drug distribution. The paper also discusses the factors affecting metabolism and renal elimination, such as drug–protein binding and metabolizing enzyme capacity. The majority of CF patients are on multidrug therapy, which increases the risk of drug–drug interactions (DDI). This is particularly true for those receiving the newly developed transmembrane conductance regulator (CFTR), as they are at a higher risk for CYP-related DDI. Our research highlights the importance of meticulously evaluating PK variations and DDIs in drug development and the therapeutic management of CF patients.
19 April 2021 in Biopharmaceutics & Drug Disposition
The aim of the study is to evaluate the effectiveness of the pediatric sofosbuvir weight-based dosing strategy in providing an equitable drug exposure compared to the marketed dose. The physiologically based pharmacokinetic (PBPK) modeling and simulation is a valuable tool in assessing drug dosing and toxicity in populations with physiological, pathological, and genetic pharmacokinetic (PK) variability. The PBPK model of the sofosbuvir compound was developed using Simcyp® V20. The model was developed and verified using the published sofosbuvir’s physicochemical properties and clinical data from multiple studies on healthy adult volunteers, hepatitis C virus (HCV)-infected adults, and HCV-infected pediatrics. The AUC and Cmax fold ratio of (predicted/observed) fell within the acceptable range of 0.5–2 in all tested adults’ data, confirming the successful development of the sofosbuvir Simcyp® compound model. Using this model, a weight-based dosing regimen of 6 mg/kg in pediatric patients was simulated and compared to the 150 mg and 200 mg approved dose for 3–6 and 6–12 y/o pediatric patients, respectively. No dose adjustment was recommended in patients ages 6–12 y/o. However, compared to the approved 150 mg for 3–6 y/o, the weight base dose provided an equitable drug exposure to adults. Further clinical studies are warranted to verify this finding.