Theses (MSc. Analytical & Pharmaceutical Chemistry)

Wound healing is a complex biological process requiring a coordinated response to restore damaged tissue. Traditional wound dressings such as gauze and bandages provide protection but lack bioactivity, delaying healing. In addition, drug-resistant bacteria are an ever-evolving issue that poses a problem. This limitation can lead to prolonged recovery times and increased susceptibility to infections. This study investigated sodium alginate-carboxymethyl cellulose composite hydrogels incorporating bioactive glass and alizarin for wound healing applications. Formulations made up of sodium alginate and sodium carboxymethyl cellulose, alizarin, and bioactive glass were prepared via lyophilisation. Fourier transform infrared spectroscopy confirmed the presence of sodium alginate, sodium carboxymethyl cellulose, alizarin, and bioactive glass and indicated successful incorporation of these components. Scanning electron microscopy explored the porosity of the samples and proved that alginate-carboxymethyl cellulose hydrogels have the most pores present to facilitate and house active components. Antioxidant assays showed alizarin’s dose-dependent radical scavenging activity. At the same time, drug-release studies indicated near-complete alizarin release within 168 hours. Degradation in PBS was slower in bioactive glass-rich formulations. Antibacterial studies against Staphylococcus aureus and Pseudomonas aeruginosa showed that samples with an equal ratio of bioactive glass and alizarin showed the highest reduction in the bacteria strains compared to the control. MTT assays indicated that alginate-carboxymethyl cellulose hydrogels and samples with bioactive glass only exhibited the highest number of living and healthy cells compared to alginate-carboxymethyl cellulose with alizarin incorporated. Finally, in scratch assays, the sample with equal alizarin and bioactive glass ratios displayed the most rapid wound closure, suggesting that a balance of components can significantly enhance wound healing. Overall, this study demonstrates that combining sodium alginate, sodium carboxymethyl cellulose, bioactive glass, and alizarin can produce hydrogels with promising antioxidant, antibacterial, and tissue-regenerative properties for wound-healing applications. However, further optimisation may be required to balance cytocompatibility and antibacterial efficacy.

Nanofibers have become a prominent research focus in wound dressing applications due to their exceptional material properties. The drug-loaded nanofibers can effectively eliminate the bacterial growth in the wound site. This study presents the formulation and fabrication of chitosan-gelatin (CS-GEL) nanofibers incorporated with curcumin and copper/zinc-based metal-organic framework (Cu/Zn-MOF) using the electrospinning method. The Cu/Zn-MOF was analysed using X-ray diffraction (XRD). The CS-GEL nanofibers loaded with curcumin and copper/zinc MOF were characterized with ATR-FTIR spectroscopy and scanning electron microscopy (SEM). The in-vitro antioxidant, anti-inflammatory, cytotoxicity, and antibacterial properties were also evaluated. The optimal conditions for smooth nanofiber production were identified as a polymer concentration of 3% (w/v) chitosan and 45% (w/v) gelatin, with a 30:70 chitosan-to-gelatin ratio. The optimized electrospinning parameters included an applied voltage of 18 kV, a flow rate of 0.8 mL/h, and a working distance of 15 cm. The optimized concentration of curcumin-Cu/Zn-MOF/CS-GEL nanofibers showed no toxic effects on HaCaT cells in 5% (w/v) of curcumin. Additionally, the 5CUR/10CuZn-MOF/CS-GEL nanofiber sample showed the highest percentage of DPPH radical scavenging (83.70%) for antioxidant activity. The highest percentage inhibition for the formulation of curcumin and MOF was 83.10%. The incorporation of curcumin and Cu/Zn-MOF effectively inhibited the growth of S. aureus and P. aeruginosa in antibacterial assays. The 5CUR/10CuZn-MOF/CS-GEL nanofiber sample was the most effective formulation against S. aureus and P. aeruginosa for antibacterial test. The 5CUR/10CuZn-MOF/CS-GEL nanofiber sample also showed the anti-biofilm effect against S. aureus. The 5CUR/1CuZn-MOF/CS-GEL, 5CUR/5CuZn-MOF/CS-GEL and 5CUR/10CuZn-MOF/CS-GEL nanofiber samples demonstrated potential applications for wound healing, as they were non-toxic to cells and exhibited antibacterial activity, which showed wound healing rate of 95.30%, 99.30% and 96.96%, respectively. The potential application of advanced wound dressings and nanotechnology lies in their ability to enhance healing rates and improve treatment outcomes.

Omega-3 fatty acids (ω-3 FAs) includes eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have attracted considerable interest for their likely health advantages. Many different benefits have been claimed for ω-3 fish oils, including preventing cardiovascular diseases (CVD), reducing cognitive decline, and helping improve and manage inflammatory diseases such as asthma, neurodegeneration, and arthritis. This study investigates the chemical profiles and heterogeneity of various commercial omega-3 fish oil products by chemometric cluster analysis of spectroscopic data, with specific focus on correlating these findings with their neuroprotective activity in microglial cells. Acquiring spectra was enabled using spectrophotometers: FTIR (Shimadzu) and 1H-NMR-Nanalysis equipped with MestReNova software operating at 61 MHz. A bioassay experiment was performed on the BV2 Murine microglia cell line, where Nitrite (NO) production was measured through the Griess assay. The NMR spectra were analyzed through chemometric analysis by principal component analysis (PCA), identifying patterns for the classification of the samples by determining similarities among them based on potency and establishing the relationship between the spectra data and NO production of the samples. The assessment of fish oils using spectroscopy techniques (FTIR and 1H-NMR) revealed the presence of ω-3 FAs compounds as their spectra fitted the DHA and EPA reference standards. The concentrations of the fish oils corresponded relatively inversely with the NO production measured through the Griess assay. DHA and EPA significantly reduced NO production on BV2 microglial cells, revealing the neuroprotective properties. The concentration range of DHA and EPA determined in samples was meaningful to exhibit the corresponding neuroprotective properties of the compounds.

Metformin hydrochloride is one of the most conventional medications used to treat diabetes, while dapagliflozin is one of the SGLT2 pharmacological inhibitors. This study aimed to establish and validate an HPLC dissolution method for the simultaneous measurement of dapagliflozin and metformin hydrochloride in a combination extended-release tablet, in accordance with the ICH recommendations. The Xbridge C18 150 x 4.6 mm, 5 μm column, mobile phase consists of methanol and io-pairing agent buffer in gradient mode operated at 1.0 mL/min and 30oC were used to create the ideal chromatographic conditions that detect the peaks at 230 nm. The method's linearity, accuracy, precision, and robustness were demonstrated by its successful development and validation. Throughout 24 hours, both the solutions of standard and sample were stable at room temperature. In vitro dissolution profile testing in pH 1.2, 4.5 and 6.8 dissolution media using innovator drug, Xigduo XR tablet have been conducted and the results passed the dissolution specifications. The validated HPLC method as well as in vitro dissolution profile information will be useful to the generic pharmaceutical industries for product registration.

Everolimus is a mammalian target of a rapamycin inhibitor drug approved for treating advanced-stage, metastatic cancer that is non-responsive to endocrine therapy. Like most chemotherapeutic drugs, everolimus comes with numerous side effects, and the severity of these side effects often varies from patient to patient. In hopes of curbing the side effects during the treatment process, it was reported that some patients default to complementary and alternative medicine (CAM) in the form of natural product-based dietary supplements. One of the natural product supplements that was reported to have been consumed by patients undergoing everolimus treatment is curcumin. Following the consumption of curcumin during everolimus treatment is a significant fall in everolimus blood concentration levels (Cmin.). It was speculated that curcumin induces CYP3A4 activity, thus increasing everolimus metabolism. However, whether the effects of curcumin on everolimus metabolism are CYP3A4-related is yet to be proven, as there are other possible ways for curcumin to be involved in decreasing everolimus Cmin in patients. One of them includes the possibility of physicochemical interaction. The primary objective of this project was to investigate the potential chemical interaction(s) that could occur between everolimus and certain selected natural compounds (rutin, quercetin and curcumin) when present in an aqueous matrix under different physiological pH environments via HPLC. The occurrences of said interactions are depicted by the appearance of unknown peaks in sample chromatograms whereby everolimus was paired with other foreign compounds. These unknown peaks were not detected in the control samples, whereby everolimus stands as the lone compound. Not all peaks present in the sample chromatograms are integrated and quantified. As a pre-requisite, the unknown peaks that are isolated in sample chromatograms mustn’t be present in blanks or controls. Only the unknown peaks that share the same spectral profile as the primary molecule, everolimus are captured and quantified. Based on the findings of this investigation, everolimus is most unstable in the presence of the natural compounds when incubated in pH 6.8 medium. The degree of instability of everolimus was depicted by the number of unknown peaks present. This indicates that more chemical interactions take place between everolimus and the natural compounds at a pH 6.8 environment compared to other pHs. Also, in pH 6.8, everolimus is most unstable and degrades rapidly when paired individually with the natural compound quercetin. The extent of interaction that takes place between everolimus and each natural compound differs. When in the presence of all three natural compounds at once, the rate of degradation of everolimus is highest at pH 6.8. The rate of degradation is interpreted as the formation of unknown peaks per unit time. However, in a pH 4.5 environment, everolimus has the most interaction when individually paired with curcumin. Most of the unknown peaks observed in single-paired samples are not found in the control sample. Based on the evidence gathered, the stability of everolimus in different pH environments is highly affected by the presence of natural compounds.