V 630 uv vis spectrophotometer

Designed SLNs loaded with 40 mg equivalent FX dispersed in 5mL phosphate buffer (pH 6.8), filled in dialysis tubbing tied at both ends with surgical sutures. The dialysis bag was then placed in an acceptor chamber (beaker) containing 50mL of phosphate buffer (pH 6.8), agitated at 50 rpm. The assembly was on a thermostatically controlled time-programmed magnetic stirrer, maintained at 37 ± 0.5 °C. At predetermined time intervals, 0.5 mL aliquots were withdrawn and replaced with fresh PBS to marinate the sink conditions. The sample was analyzed spectrophotometrically using a UV lamp emitting λ_max 225 nm radiations (UV-VIS Spectrophotometer, V-630, Jasco, Pfungstadt, Germany). The amount released was plotted against time intervals, and drug release data was then fitted to the mathematical models to postulate kinetic orders. Linear regression analysis was followed by using the below equations [18 (link),48 (link),49 (link),50 (link)].
$$\frac{M_t}{M_0} =K_0\times \mathsf{t} \mathrm{Zero} \mathrm{Order}$$
$$ln\left(\frac{M_t}{M_0}\right) =K_1\times \mathsf{t} \mathrm{Zero} \mathrm{Order}$$
$$\frac{M_t}{M_0} =K_H \times t_{1/2} \mathrm{Higuchi} \mathrm{Model}$$
$$\frac{M_t}{M_0} =K_{KP} \times t_n \mathrm{Korsmeyer-Peppas}$$
where K is the kinetic rate constant, M_t/M₀ is the fraction of FX released at time t, and n is the diffusion exponent. The value of which describes the release mechanism. Wherein if n = 0.5 (Fickian diffusion), 0.5 < n < 1.0 (Anomalous non-Fickian transport), and for n = 1.0 (Case-II, relaxational)

Grass and hemp biomass was subjected to preliminary crushing to particles of size 20–40 mm and dried at 50–55 °C for 24 h. Then, the material was disintegrated on knife mill SM-200 (Retsch, Hann, Germany) with a sieve of the mesh size of 2 mm.
The next step was the alkaline treatment of the halophyte biomass for 5 h with 1.5% sodium hydroxide at 90 °C [39 (link)]. NaOH/biomass weight ratio was 10:1. After the alkaline pretreatment was carried out, the biomass solution was filtered on a Büchner funnel, then washed with distilled water until neutralised, and dried in a laboratory dryer at 50 °C for 24 h. The alkali effect on the content of the released reducing sugar was determined using Miller’s method with 3,5-dinitrosalicylic acid (DNS) [40 (link)]. The raw material was incubated at 40 °C in 0.05 M citrate buffer pH 4.8 for 2 h using the enzyme preparation Flashzyme Plus 200 (AB Enzyme) at the dose of 20 FPU·g⁻¹. The absorbance of the supernatant was measured at 530 nm on UV–VIS Spectrophotometer V-630, (Jasco, Pfungstadt, Germany).

The catalytic (esterification) activity of lipase TL was assayed according to the reported literature (Gumel et al. 2013a (link), b (link), c (link)), using a microchanneled reactor system equipped with micromixers (LTF-Mx and LTF-Vs; Little Things Factory, Germany). The enzyme (30 µL mL⁻¹ of reaction mixture) was added to a vial containing 10 mL of 10 mM 4-nitrophenyl palmitate solution in dichloromethane under continuous mixing and drawn into a 10-mL borosilicate glass syringe. 10 mL of 10 mM ethanol was drawn into another glass syringe. The contents of these two syringes were simultaneously fed into the microreactor at a flow rate of 0.5 mL min⁻¹ using automatic infusion pump. Aliquots (50 µL each) of the reaction mixture were withdrawn at intervals and quenched by mixing with 1 mL of 0.1 M NaOH in a quartz cuvette. The 4-nitrophenol liberated by the reaction was measured at 412 nm (UV–Vis spectrophotometer V-630; Jasco, Japan) against a blank of distilled water. The enzyme activity was calculated as the initial slope of the progress curve of 4-nitrophenol liberation versus time.