Faculty of Pharmacy

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Understanding the Infrared Multiple Photon Dissociation Spectra of Hydrogen‐Tagged Protonated Betaine: Vibrational Confinement Counteracts the Hydrogen Bonding Induced OH Stretching Frequency Downshift
(Wiley, 2025-06-11)
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Pejov, Ljupcho
<jats:p>Finite‐temperature vibrational spectra of protonated betaine and its noncovalently bonded clusters with molecular hydrogen are modeled using Lagrangian dynamics with the atom‐centered density matrix propagation (ADMP) scheme. The focus is put on the O-H stretching mode, which serves as a primary indicator of the type and strength of the noncovalent intermolecular interactions. The computed anharmonic OH stretching vibrational frequency shifts in the case of protonated betaine upon tagging with H<jats:sub>2</jats:sub> at the OH group site at 40 K are in quantitative agreement with the experimental infrared multiple photon dissociation data. The shifts computed from simulations at 4 K contain only the harmonic contributions. It is found that this is a consequence of vibrational confinement of the O-H oscillator caused by the H<jats:sub>2</jats:sub> tagger, which remains close to the vibrating atoms throughout the simulation and counteracts the frequency redshift induced by the weak hydrogen bonding interaction. Changes in the O-H stretching potential, along with a small but observable confinement relaxation at 40 K leads to O-H stretching frequency downshift as compared to 4 K. Application of the two‐trace 2D correlation analysis of the computed vibrational density of states spectra enables a clear distinction between bands of different origin to be made.</jats:p>
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Molecular Hydrogen Acts as a Hydrogen Bond Proton Acceptor: From Protonated Betaine Tagging to the Weakest Hydrogen Bond
(American Chemical Society (ACS), 2024-05-09)
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Pejov, Ljupcho
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Cannabinoid production in various Cannabis sativa L. in vitro cultures
(Springer Nature, 2025-01-02)
Ana Trajkovska;
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Oliver Tusevski;
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Iskra Davkova;
The main goal of this study was to develop an efficient micropropagation protocol for cannabis (Cannabis sativa L.) and to summarize the influence of plant growth regulators on cannabinoid production in various in vitro cultures. Three in vitro culture lines were obtained during cannabis micropropagation and referred to calli, shoots, and plantlets. Shoot multiplication was examined on apical segments isolated from in vitro seedlings and cultivated on solid MS/B5 medium supplemented with various concentrations (0.05-1.0 mg·L− 1) of thidiazuron (TDZ). Callogenesis was induced from leaf explants of seedlings in the presence of 1.0 mg·L− 1 TDZ and 0.5 mg·L− 1 1-naphthaleneacetic acid (NAA), while further biomass production was evaluated upon TDZ (0.5-2.0 mg·L− 1). The shoot regenerative potential was assessed on various concentrations (0.1-1.0 mg·L− 1) of indole-3-butyric acid (IBA). The HPLC-DAD analysis of cannabinoids revealed that cannabidiolic acid (CBDA), cannabidiol (CBD), cannabinol (CBN), ∆9-tetrahydrocannabinol (∆9-THC), and ∆9-tetrahydrocannabinolic acid (∆9-THCA) were the main identified cannabinoids in calli, shoots and regenerated plantlets. The superior production of Δ9-THC was observed in multiple shoots cultured on 0.05 mg·L− 1 TDZ (49.23 mg·g− 1), callus cultures treated with 1.0 mg·L− 1 TDZ (3.92 µg·g− 1), as well in plantlets regenerated on hormone-free medium (80.1 mg·g− 1). The Δ9-THC content in the leaves of 6-month-old regenerated plantlets was significantly higher (1.6-fold) than that of the mother plant. Cannabinoid contents in the inflorescences of the mother plant were higher or even comparable to those observed for acclimatized plantlets. In conclusion, cannabis in vitro cultures could be proposed as promising systems for cannabinoid production.
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Assessment of cytotoxic impact of wild grown Lavandula angustifolia essential oil encapsulated in liposomes and nanoemulsions on DU145 cancer cell line
(Marmara University Press, 2024-12)
Mimoza BASHOLLI-SALIHU
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Aida LOSHAJ-SHALA
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Art ÇUNAKU
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Venesa LUPÇI
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Ufuk BAǦCI
The cytotoxic activity of free and nanoencapsulated essential oil of Lavandula angustifolia (LEO) was evaluated in this study. The aim was to produce different nanoformulations (NF) of LEO to improve the physicochemical properties of NF and the cytotoxic activity of LEO in the DU145 cancer cell line. Essential oil-based liposomes (LEO-Lipoid S100, -Ph 85G, and -Ph 90H) and nanoemulsions (LEO-NE) were prepared by ethanol injection method and high-pressure homogenization, respectively. LEO demonstrates measurable in vitro cytotoxic activity against the DU145 cell line (IC50 75 μg/mL). NE and Ph90H LS significantly enhanced its cytotoxic activity, while LEOLipoid S100 LS and LEO-Ph 85G LS showed no significant difference. LEO-Ph 90H LS and LEO-NE demonstrate stable nanosystems and enhanced cytotoxic potential against the DU-145 cancer cell line, suggesting promising therapeutic benefits for future application. Further studies involving in vivo experiments are necessary to validate and extend these findings.
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Development of novel portable NIR spectroscopy process analytical technology (PAT) tool for monitoring the transition of ibuprofen to ibuprofen sodium during wet granulation process
(Elsevier BV, 2024-09-05)
Atanaskova, Elizabeta
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Angelovska, Veronika
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Chachorovska, Marina
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Anevska Stojanovska, Natasha
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Petrushevski, Gjorgji
The aim of this research was to develop a process analytical technology (PAT) tool for monitoring the transformation of the active ingredient ibuprofen into the fast-dissolving salt ibuprofen sodium during the wet granulation process. Two near-infrared (NIR) spectrophotometers, portable and benchtop spectrophotometer, were compared. During the analysis with the built models, both demonstrated comparable accuracy and precision (R2X = 0.995, R2Y = 0.927, Q2 = 0.995, and R2X = 0.990, R2Y = 0.948, Q2 = 0.992, respectively). Considering the applicability, a model based on the portable NIR spectroscopic data was chosen for further development and application as a PAT tool for monitoring different steps during the wet granulation process. The evaluation of the model's predictive capability involved analyzing laboratory trial batches with varying amounts of sodium carbonate, resulting in different concentrations of ibuprofen sodium at the end of the wet granulation process. Subsequently, tablets were manufactured from each trial batch, followed by dissolution analysis. The dissolution rate assays were in good agreement with the NIR-predicted concentrations of ibuprofen sodium at the end of the wet granulation process. Based on the results, the proposed model provides an excellent tool to monitor the ibuprofen acid-salt transformation, to determine the end-point of the reaction, and to efficiently control the wet granulation process.
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FT-NIR models for predicting film quality parameters in titanium dioxide-free tablet coatings
(Elsevier BV, 2025-02-01)
Gorachinov, Filip
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Koviloska, Monika
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Tnokovska, Katerina
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Atanasova, Ana
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Antovska, Packa
This study leverages Fourier Transform Near-Infrared (FT-NIR) spectroscopy to monitor the coating process of pharmaceutical tablets using PVA-based TiO2-free films, with talc and iron oxides as opacifiers. By employing a combination of multivariate analytical techniques, the correlation between film coating progression and film thickness was evaluated. Assessment of coating thickness for different coating levels was performed by optical microscopy. Additionally, using colorimetric analysis by scanner method, the color progression for different coating levels was evaluated and expressed as the a* value from CIELAB color space. The coordinate value a* showed predictable changes with the progression of the coating process and film thickness values, indicating its utility as a robust reference method for quality control and process optimization. The predictive capability of the OPLS models, validated against measured film thickness and the a* value, demonstrated low prediction errors and confirmed the models' effectiveness in distinguishing coating levels and accurately predicting film coating progression. The OPLS model used knowledge-based peaks of interest, which were further confirmed by loading and coefficient plots. The study demonstrated that film thickness, as a destructive, and a* value from CIELAB color space, as a non-destructive reference method for coating progression could be used during a controlled pharmaceutical coating process for product quality assessment and pharmaceutical process endpoint determination.
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3D printed extended-release hydrochlorothiazide tablets
(Elsevier BV, 2025-03-01)
Tasevska, Teodora
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Adamov, Ivana
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Ibrić, Svetlana
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In this study 3D printed tablets (printlets) with extended release of hydrochlorothiazide (HHT) as model active ingredient were designed and developed. Four formulations, F0.1SSE, F1SSE, F0.1DLP and F1DLP, have been manufactured and characterized, using non-typical semi-solid extrusion (SSE) with UV light solidification and digital light processing (DLP) techniques. Obtained rheological studies pointed out to F1SSE and F1DLP as more suitable for SSE and DLP printing, respectively. Photopolymerization process between photopolymer (PEGDA) and photoinitiator (DPPO; 0.1% and 1%) was investigated using FTIR, with PCA modeling utilized to analyze spectral variations over time and estimate crosslinking kinetics. SSE printlets averaged ∼6.5 mm in diameter, ∼3 mm in height and ∼110 mg in mass, while DLP printlets averaged ∼8.5 mm in diameter, ∼2.5 mm in height, with masses of ∼170 mg (F0.1DLP) and ∼220 mg (F1DLP). All four formulations complied to the requirements of European pharmacopeia for uniformity of dosage units of single dose preparations. In vitro release studies indicated extended-release profiles in both 0.1M Hydrochloric acid (HCl) and phosphate buffer pH 6.8 for SSE and DLP printlets. The release kinetics of HHT from the printlets were modeled to fit First order, Higuchi, Korsmeyer-Peppas and Hixson-Crowell equations and the most probable ones were determined based on the R2 values and Akaike information criterion. FTIR and Raman spectroscopic analyses of printlets confirmed the presence of characteristic peaks from both, HHT and excipients, as well as modifications in bonds due to the photopolymeric reaction.
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Differentiation of Cannabis seeds employing digital morphological screening and infrared spectroscopy coupled with multivariate modeling
(Elsevier, 2024-05-01)
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Trajkovska, Ana
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Cultivation of Cannabis for medicinal purposes primarily relies on seed propagation with expected variations in yield, cannabinoid content, growth rate and seed material non-uniformity. This study aims to employ digital methods for morphological analysis and infrared spectroscopy, combining them with multivariate analysis to characterize and differentiate Cannabis seeds. Morphological traits of 100 seeds from both commercial Cannabis specimens and wild-growing local varieties were analyzed using the high-throughput phenotyping software in addition to their collected infrared spectra in the mid-IR region. Subsequently, a chemometrics approach by means of Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA), and Partial Least Square-Discriminatory Analysis (PLS-DA) was applied. The statistical indicators of the PLS-DA model (R2X=0.99, R2Y=0.63, Q2=0.64) demonstrate strong predictive capabilities for the differentiation of Cannabis seed specimens based on morphological attributes. The score scatter plot clearly shows a distinct grouping pattern, primarily driven by seed size. Wild-type seeds predominantly cluster into group 1, characterized by smaller diameters, while commercial seeds cluster into group 2. By analysing spectral data, in contrast to the expected differentiation based on secondary metabolites (cannabinoids) in the seeds, differentiation was based on the macronutrient profile with characteristic bands at 3275 cm−1, 2921 cm−1, 2852 cm−1, 1743 cm−1, 1630 cm−1, 1532 cm−1, 1459 cm−1, 1239 cm−1, 1157 cm−1, 1094 cm−1, 1018 cm−1, identified as the most distinctive spectral features. The PCA model (R2X=0.88 and Q2=0.85) was composed of 5 principal components explaining 88% of the spectral variations. The loading plot of the PLS-DA model reveals the distinctive spectral features for both groups (lipid and carbohydrate bands - group 2 samples, protein and water content - group 1 samples). The developed models have the potential for application for rapid screening of quality parameters of Cannabis seeds and their differentiation.
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Bootstrap analysis for dissolution similarity factor f2 - bringing confidence for borderline results – a case study
(Macedonian Pharmaceutical Association in cooperation with Ss. Cyril and Methodius University in Skopje, Faculty of Pharmacy., 2022)
Tina Achkoska
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Marijana Bozhinovska
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Angela Arnaudova
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Packa Antovska
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In vitro dissolution testing is one of the most important tools for characterizing the performance of oral solid dosage forms. In order to demonstrate similarity between test and reference product, comparative dissolution profiles are performed. Selection of a suitable method for comparison of the dissolution profile of the reference product and the test product is of great importance especially in the case of biowaivers when similarity assessment is based on the in vitro data only. Various approaches have been developed for the comparison of dissolution profiles, however the usage of the f2 similarity factor is widely accepted due to its simplicity. When the conditions for using f2 similarity factor are not fulfilled due to high variable dissolution profiles, f2 bootstrap method is then recommended. The focus of this study is to see whether it is benefitial f2 bootstrap analysis to replace the usage of simple f2 for comparison of dissolution profiles that fulfill the prerequisites for using the f2 method in cases when borderline f2 results are obtained.
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A stability-indicating HPLC method for determination of folic acid and its related substances in tablets
(Macedonian Pharmaceutical Association in cooperation with Ss. Cyril and Methodius University in Skopje, Faculty of Pharmacy., 2022)
Kristina Grncharoska
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Elena Lazarevska Todevska
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Irena Slavevska Spirevska
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Tanja Bakovska Stoimenova
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In this study, a simple stability-indicating HPLC method for determination of folic acid and its related substances in tablets was optimized and validated. Chromatographic separation was performed on Inertsil C8, 250 x 4.6 mm, 5 μm, using isocratic elution with mobile phase consisting of methanol and phosphate buffer (pH=6,4) (12:88, v/v %). The injection volume was 5 μL and the eluted compounds were monitored at 280 nm. The flow rate was 0.7 mL/min and the column temperature was maintained at 30 ˚C. Forced degradation studies were conducted to investigate the stability-indicating ability of the method. The method was validated according to the ICH guideline requirements with respect to selectivity/specificity, linearity, limit of detection, limit of quantification, accuracy, precision and robustness. The results from the forced degradation study confirmed satisfactory resolution between folic acid and obtained specified impurities (imp. A, imp. C, imp. D, imp. E and PABA) as well as satisfactory resolution between all other formed degradation products, proving that the method is stability-indicating. The optimized and validated method is selective and precise, capable of detecting and quantifying all folic acid related substances. The obtained results from validation parameters imply that the proposed method is suitable for its purpose and can be used for routine quantification of folic acid and its related substances in tablets.

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