Synthesis, Characterization, and In Vitro Release Kinetics of L-Serine Encapsulated in PVP Nanoparticles
نویسندگان
1 Department of Ophthalmology, Samarkand State Medical University, Samarkand, Uzbekistan
2 Department of General Chemistry, Faculty of General Education Departments, Tashkent State Technical University, Tashkent, Uzbekistan
3 Department of Propedeutics of Internal Diseases, Bukhara State Medical Institute, Bukhara, Uzbekistan
4 Department of Propedeutics of Internal Diseases, Bukhara State Medical Institute, Bukhara, Uzbekistan
5 Tashkent State Medical University, Tashkent, Uzbekistan
6 Department of Orthodontics and Dental Prosthetics, Tashkent State Medical University, Tashkent, Uzbekistan
7 Department of Advanced Training of Medical Workers with Secondary Education, Tashkent State Medical University, Tashkent, Uzbekistan
8 Department of Russian Language and Literature, Bukhara State Pedagogical Institute, Bukhara, Uzbekistan
9 Department of Propedeutics of Internal Diseases, Bukhara State Medical Institute, Bukhara, Uzbekistan
10 Fergana Medical Institute of Public Health, Fergana, Uzbekistan
11 Tashkent Pharmaceutical Institute, Tashkent, Uzbekistan
12 Tashkent Pharmaceutical Institute, Tashkent, Uzbekistan
13 Department of Pharmacy and Chemistry, Alfraganus University, Tashkent, Uzbekistan
doi
10.22052/JNS.2026.02.023چکیده
L-Serine, a polar amino acid with neuromodulatory significance, presents formidable delivery challenges owing to its hydrophilic character and rapid systemic clearance. Herein, we report the fabrication of L-serine-loaded polyvinylpyrrolidone nanoparticles via modified nanoprecipitation, affording spherical, monodisperse populations with mean diameter of 78.4 ± 16.2 nm and smooth surface morphology as evidenced by field-emission scanning electron microscopy. Fourier transform infrared spectroscopy established that encapsulation proceeds through specific hydrogen bonding interactions between the PVP carbonyl and the ammonium and hydroxyl functionalities of serine, while the carboxylate moiety remains largely unperturbed. X-ray diffraction analysis confirmed complete amorphization of the crystalline amino acid upon encapsulation, with molecular dispersion within the amorphous polymer matrix rather than persistence as discrete crystalline domains. In vitro release studies conducted under simulated physiological conditions revealed pH-dependent liberation profiles with accelerated release under acidic environments attributable to protonation-mediated weakening of drug-polymer hydrogen bonds. Kinetic modeling demonstrated that serine release is best described by the Korsmeyer–Peppas equation with release exponent n = 0.47, indicating anomalous (non-Fickian) transport wherein diffusion and polymer chain relaxation operate concurrently. Release kinetics were systematically tunable through rational selection of polymer molecular weight and drug loading, with activation energy determined as 32.7 ± 2.1 kJ·mol⁻¹ via Arrhenius analysis. This work establishes a mechanistically grounded framework for hydrophilic amino acid delivery using PVP nanocarriers, offering quantitative predictive capacity for formulation optimization.
