Denitsa Nikolova

Ms. Denitsa Nikolova


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 March 2023 in Pharmaceutics
Verified
Journal Article
Open access
PDF file
DGDilyana Georgieva
Dilyana Georgieva
DNDenitsa Nikolova
Denitsa Nikolova
EVElena Vassileva
Elena Vassileva
BKBistra Kostova
Bistra Kostova
Natural alkaloid galantamine is widely used for the treatment of mild to moderate Alzheimer’s dementia. Galantamine hydrobromide (GH) is available as fast-release tablets, extended-release capsules, and oral solutions. However, its oral delivery can cause some unwanted side effects, such as gastrointestinal disturbances, nausea, and vomiting. Intranasal administration is one possible way to avoid such unwanted effects. In this work, chitosan-based nanoparticles (NPs) were studied as potential GH delivery vehicles for nasal application. The NPs were synthesized via ionic gelation and studied using dynamic light scattering (DLS) as well as by spectroscopic and thermal methods. The GH-loaded chitosan–alginate complex particles were also prepared as a way to modify the release of GH. The high loading efficiency of the GH was confirmed for both types of particles, at 67% for the GH-loaded chitosan NPs and 70% for the complex chitosan/alginate GH-loaded particles. The mean particle size of the GH-loaded chitosan NPs was about 240 nm, while the sodium alginate coated chitosan particles loaded with GH were expectedly bigger, with a mean particle size of ~286 nm. GH release profiles in PBS at 37 °C were obtained for both types of NPs, and it was found that the GH-loaded chitosan NPs allowed the prolonged release of the incorporated drug for a period of 8 h, while the complex GH-loaded chitosan/alginate NPs released the incorporated GH faster. The stability of the prepared GH-loaded NPs was also demonstrated after 1 year of storage at 5 °C ± 3 °C.

30 January 2023 in Gels
Verified
Journal Article
Open access
PDF file
DNDenitsa Nikolova
Denitsa Nikolova
CTChristo Tzachev
Christo Tzachev
LCLachezar Christov
Lachezar Christov
EVElena Vassileva
Elena Vassileva
The study reveals the development of novel hydrogels based on sulfobetaine methacrylate (SB) and vinyl pyrrolidone (VP) copolymers as potential contact lenses delivery systems of timolol maleate (TM). The novel copolymer networks demonstrated composition dependent swelling kinetics, where the hydrophilicity of VP and the physical network of SB monomeric units play significant roles. TM loading efficiency appeared to slightly depend on the copolymeric composition, increasing upon VP monomeric unit increase. In contrast, the TM release was prolonged when the SB monomeric units content in the copolymers increased, reaching full drug release for 48 h for the SB-rich networks. The transparency of the hydrogels was also studied and the obtained values demonstrate their applicability as potential materials for soft contact lenses. The study has revealed the potential of these novel copolymeric hydrogels as materials for contact lenses delivery systems of timolol maleate.