Model uv 1800 240 5

Each film sample was cut into small pieces from five different regions of the film including the center. Each film sample was placed in 10 mL distilled water at 37 ± 0.2 °C and stirred overnight using a magnetic stirrer until completely dissolved (Pawar et al., 2013 (link)). The obtained solutions were then diluted with distilled water and assayed using a UV spectrophotometer (SHIMADZU Corporation, Model UV-1800 240 V, Japan) at a fixed λ_max value of 251 nm against distilled water as a blank. The percentages of the drug content were calculated using the following equation:
$$\text{Drug content}(\%)\; =\frac{AQ}{TQ}\mathrm{\times \; 100}$$
*AQ is the actual quantity of the drug available in the film. *TQ is the theoretical quantity of the drug.
The experiment was repeated in triplicates. The mean and standard deviation were calculated for each film sample.

In vitro release studies of LNZ from bio-composite films and free LNZ were conducted using the Incubator Shaker apparatus (ZHICHENG ZHWY-2102C, China). Working conditions of the equipment were adjusted to incubate at 32 ± 0.2 °C to mimic the skin temperature and at a rotational speed of 50 rpm throughout the experiment (Jantrawut et al., 2017 (link)). Each film sample of 3 cm² was cut and immersed in a glass vial comprising 100 mL of PBS (pH 7.4) as a dissolution medium. Aliquots of 3 mL were withdrawn using a syringe from each glass vial at fixed time intervals at 5, 10, 20, 30, 45, 60, 90, 120 minutes, then at 3, 4, 6, and 8 h, and finally at 24 h. All of the withdrawn aliquots were immediately replenished with an equivalent volume of fresh PBS (pH 7.4) after each sampling to maintain a constant medium volume throughout the experiment. The content of linezolid released from each film sample was determined spectrophotometrically using a UV spectrophotometer (SHIMADZU Corporation, Model UV-1800 240 V, Japan) at a wavelength of 251 nm. In vitro release studies were conducted in triplicate and were expressed as a cumulative percentage of drug release versus time.