2.4. Drug content of Mel-OCM-chitosan conjugates
Content of incorporated melphalan was determined by measurement
of the UV absorption of the conjugates solution in
distilled water at 261 nm. The Mel content was determined
with the help of a calibration curve of Mel in mixture solution
(methanol:water:acetic acid = 49.5:49.5:1) range from 2 to
50 g/mL with R2 = 0.99636. The Mel content was calculated as
follows:
2.5. Solubility of Mel-OCM-chitosan conjugates
To evaluate solubility of the conjugates and Mel, 20 mg Mel-
OCM-chitosan conjugates or Mel was added into 1 mL deionized
water respectively, and the mixtures were vortexed for 5 min,
sonicated for 5 min, and centrifuged at 6000 rpm for 5 min. The
supernatants were collected and analyzed using UV spectrophotometer.
The amounts of Mel were quantified by measuring UV
absorption at a wavelength of 261 nm.
2.6. In vitro drug release of Mel-OCM-chitosan conjugates
The chemical hydrolysis of the conjugates was carried out in
triplicates in phosphate-buffered saline (PBS) at pH 7.4 and 5.8