In vitro 5-fluorouracil release properties investigation from pH sensitive sodium alginate coated and uncoated methyl cellulose/chitosan microspheres

5-Fluorouracil (5-FU) has been in clinical practice for decades one of the oldest chemotherapy agents. However, intravenous administration of 5-FU requires the development of an oral controlled delivery system for improved patient compliances. For this purpose, 5-FU loaded and sodium alginate (NaAlg) coated and uncoated methyl cellulose (MC)/chitosan (CS) microspheres were prepared by emulsion crosslinking method using a mixture of water and oil. Firstly, MC/CS microspheres were prepared and then coated with NaAlg. The prepared microspheres were characterized by optical microscopy, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Microspheres were also characterized by equilibrium swelling values and drug release profiles. The in vitro drug release studies were carried out with three pH values 1.2, 6.8, and 7.4, respectively, each for 2 h. It was determined that coating the microspheres with NaAlg provides more controlled drug release, especially at pH 1.2. The effects of the preparation conditions, such as coating time, MC/CS ratio, NaAlg concentration, and crosslinker concentration on the 5-FU release were investigated.

Effects of comorbidities associated with COVID-19 cases in Intensive Care Unit on mortality and disease progression

OBJECTIVE

The patient's age, gender and the presence of certain concomitant diseases have been reported to play a part in the course and progression of COVID-19 in the literature. In this study, we aimed to compare the comorbidities causing mortality in critically ill Intensive Care Unit (ICU)-patients diagnosed with COVID-19.

PATIENTS AND METHODS

The data as regards the COVID-19 cases followed up in the ICU were retrospectively reviewed. 408 COVID-19 patients with positive PCR test were included in the study. In addition, a subgroup analysis was performed in patients treated with invasive mechanical ventilation. While the primary aim of this study was to evaluate the difference in survival rates due to comorbidities in critical COVID-19 patients, we also aimed to assess the comorbidities in severely intubated COVID-19 patients in terms of mortality.

RESULTS

A statistically significant increase in mortality was observed in patients with underlying hematologic malignancy and chronic renal failure (p=0.027, 0.047). Body mass index value in the mortal group was significantly higher in both the general study group and subgroup analysis (p=0.004, 0.001).

CONCLUSIONS

Advanced age and comorbidities such as chronic renal failure and hematologic malignancy in COVID-19 patients are associated with poor survival prognosis in critically ill COVID-19 patients.

Preparation of magnetite-chitosan/methylcellulose nanospheres by entrapment and adsorption techniques for targeting the anti-cancer drug 5-fluorouracil

In this work, we have formulated novel nanospheres that could be used in the controlled release of the anticancer drug, 5-fluorouracil (5-FU). The nanospheres are composed of magnetite, containing chitosan (CS) and methylcellulose (MC). The drug entrapment was achieved through the encapsulation and adsorption processes. The effects of the preparation conditions, such as magnetite content, CS/MC ratio, crosslinking concentration, exposure time to glutaraldehyde (GA), and the drug/polymer ratio were investigated for both processes. The 5-FU release was found to follow the Fickian mechanism, and the Langmuir isotherm for the nanospheres was achieved through encapsulation and adsorption processes, respectively.

Preparation of ferric ion crosslinked acrylamide grafted poly (vinyl alcohol)/sodium alginate microspheres and application in controlled release of anticancer drug 5-fluorouracil

Ionically crosslinked microspheres of acrylamide (AAm) grafted poly (vinyl alcohol) (PVA)/sodium alginate (NaAlg) were prepared by crosslinking with FeCl3 and 5-fluorouracil (5-FU), which is an anticancer drug and was successfully encapsulated into the microspheres. The graft copolymer (PVA-g-PAAm) was characterized by using Fourier transform infrared spectroscopy (FTIR) and elemental analysis. The prepared microspheres were characterized by FTIR and scanning electron microscopy (SEM). Microspheres were also characterized by particle diameter, equilibrium swelling values and release profiles. The release studies were carried out at three pH values 1.2, 6.8 and 7.4, respectively, each for 2 h. The effects of preparation conditions as PVA-g-PAAm/NaAlg ratio, drug/polymer ratio, crosslinker concentration and exposure time to FeCl3 on the release of 5-FU were investigated for 6 h at 37 °C. The highest 5-FU release was found to be as 99.57% (w/w) at the end of 6 h for PVA-g-PAAm/NaAlg ratio of 1:4 (w/w), drug/polymer ratio of 1:8 (w/w), crosslinker concentration of 0.05 M and exposure time of 10 min. The release results were also supported by the swelling measurements of the microspheres. Release kinetics was described by Fickian and non-Fickian approaches.