Determination of favipiravir in human plasma using homogeneous liquid–liquid microextraction followed by HPLC/UV

Background: Favipiravir is an antiviral drug that was recently approved for the management of COVID-19 infection. Aim: This work aimed to develop a new method, using sugaring-out induced homogeneous liquid–liquid microextraction followed by HPLC/UV for the determination of favipiravir in human plasma. Materials & methods: The optimum extraction conditions were attained using 500 μl of tetrahydrofuran as an extractant and 1400 mg of fructose as a phase-separating agent. Results: The developed method was validated according to the US FDA bioanalytical guidelines and was found linear in the range of 25-80,000 ng/ml with a correlation coefficient of 0.999. Conclusion: These results showed that the developed method was simple, easy, valid and adequately sensitive for determination of favipiravir in plasma for bioequivalence studies.

Natural Flavonoids as Superior Reagents for Separation of Clinically Important Zr Radionuclides

This paper exploits the affinity of bio-flavonoid hesperidin, isolated from orangepeel, towards the separation of clinically important 88Zr radionuclide from high energy proton bombarded yttrium target. The extraction of Zr with hesperidin was studied by solid-liquid extraction (SLX) technique over a wide pH range. The advantage of hesperidin is that it acts as separating agent as well as free-radical scavenging agent upon injection of the radionuclidehesperidin complex in-vivo. The stability of isolated hesperidin under strong radiation field was also studied. The selectivity of the bio-flavonoid towards 88Zr was maximum at pH=4 where in >78% Zr was extracted with <1% contamination from bulk yttrium target.

Natural Flavonoids as Superior Reagents for Separation of Clinically Important Zr Radionuclides

This paper exploits the affinity of bio-flavonoid hesperidin, isolated from orangepeel, towards the separation of clinically important 88Zr radionuclide from high energy proton bombarded yttrium target. The extraction of Zr with hesperidin was studied by solid-liquid extraction (SLX) technique over a wide pH range. The advantage of hesperidin is that it acts as separating agent as well as free-radical scavenging agent upon injection of the radionuclidehesperidin complex in-vivo. The stability of isolated hesperidin under strong radiation field was also studied. The selectivity of the bio-flavonoid towards 88Zr was maximum at pH=4 where in >78% Zr was extracted with <1% contamination from bulk yttrium target.

Influence of Luting Materials and Methods and the Restoration Surface on the Amount of Cement Remnants in Implant Restorations

This study aimed to investigate the effects of the luting methods on the amount of cement remnants in implant restorations and to determine the restoration surface with the maximum amount of residual cement. Forty abutments and crowns were divided into 4 groups as follows: TB group, luting with zinc oxide-eugenol cement; TBV group, luting with zinc oxide-eugenol cement after application of a separating agent over the transmucosal area of the abutment; PI group, luting with methacrylate cement; and PIV group, luting with methacrylate cement after application of a separating agent. After cementation, all the quadrants of the specimens were photographed, and the amount and location of the cement remnants were statistically analyzed (P ≤ .05). The amount of cement remnants was significantly smaller in the groups with a separating agent. The type of luting material did not significantly affect the results. Cement remnants were more abundant on the mesial and distal sides than on the buccal and lingual sides of the restoration.