German Journal of Pharmaceuticals and Biomaterials

Investigating extraction methods of coconut oil in Metronidazole-Loaded topical microsized-emulsions for management of Rosacea

2025-07-20T14:54:22-04:00

Emulsions for topical application are promising for the delivery and stability of poorly watersoluble drugs and those with challenging oral delivery. Coconut oil (oil from Cocos nucifera Linne, CNO) is used for cosmetic purposes, but there is limited published literature on its use in the delivery of drug-loaded preparations for topical or transdermal applications. The aim of this study was to formulate and evaluate metronidazole-loaded topical emulsions using CNO obtained from three different extraction methods. CNO was obtained using maceration in warm water and n-Hexane of the coconut meat to obtain hot method extract- HME, cold method extract- COE, and the chemical method extract- CME, respectively. The HME, COE, and CME were used to formulate corresponding metronidazole-loaded microsized emulsions (HMEE, COEE, and CMEE, respectively) at a predetermined oil-to-surfactant ratio of 1.5:1 using a homogenizer. The surfactant mix was composed of triethanolamine to stearic acid in the ratio of 1:10. The formulated drug-loaded emulsions were evaluated for physicochemical properties, stability, and antimicrobial activity. The chemical extraction method produced the highest CNO yield (72%), while the cold extraction method produced the lowest (32%). Drug-loaded emulsion COEE had the lowest viscosity of 4.29 Pas when compared with CMEE (4.82 Pas) and HMEE (4.6 Pas), had the least stability as reflected in its largest globule size of 28.46 μm, whereas globule size for CMEE and HMEE were 9.78 and 25.95 μm, respectively. Overall, metronidazole-loaded emulsions reduced the drug activity against the test organisms as determined by the measured zones of inhibition. These findings highlight the potential of a coconut oil-based emulsion for the topical delivery of drugs (e.g., metronidazole); however, for biocompatibility and to achieve the intended therapeutic outcome, careful selection of the drug of choice incorporated into the formulation for the target organism is needed. Also, while the chemical method of extraction for coconut oil would be a good choice to achieve a higher yield, the emulsion prepared from CNO using the hot extraction method showed adequate stability.

Role of Photosensitizers in Photodynamic Therapy of Cancer Treatment: A Comprehensive Review

2025-05-26T15:39:31-04:00

Photodynamic therapy (PDT) is a clinically approved, minimally invasive treatment that uses a photosensitizer (PS), a specific wavelength of light, and molecular oxygen to induce localized cytotoxic effects in cancerous tissues. Upon light activation, the photosensitizer generates reactive oxygen species (ROS), particularly singlet oxygen, leading to oxidative damage, apoptosis, or necrosis of tumor cells. The effectiveness of PDT is critically influenced by the properties of the photosensitizer, including its absorption spectrum, photostability, tumor selectivity, and pharmacokinetics. Over the years, photosensitizers have evolved from first-generation compounds, which suffered from poor specificity and prolonged skin photosensitivity, to second- and thirdgeneration agents with enhanced light absorption, reduced toxicity, and tumor-targeting capabilities. Recent innovations focus on nanotechnology-based delivery systems, targeted conjugates, and photoactivatable prodrugs to overcome current limitations such as non-specific accumulation, limited light penetration, and tumor hypoxia. Moreover, the combination of PDT with emerging therapies such as immunotherapy and molecular-targeted treatments is being actively explored to achieve synergistic effects and long-term tumor control. With ongoing advances in molecular design, imaging integration, and bioengineering, PDT is being refined as a more precise and effective tool in the oncologist’s arsenal. This review provides a detailed examination of the central role of photosensitizers in PDT, including their mechanisms of action, classifications, challenges in clinical implementation, and the latest strategies to optimize their performance in cancer treatment.

Modeling Microbial Density Trend in Pharmaceutical Water with Irregular Intervals using CART Regression

2025-07-20T15:31:21-04:00

Monitoring and controlling the microbiological quality of water in the pharmaceutical and biopharmaceutical industries is paramount to ensure the safety and quality of intermediate and final medicinal products. An integral task of the quality system is to trend, interpret, and investigate this crucial inspection characteristic. Analyzing time series data with irregular sampling intervals presents a significant challenge, particularly when standard methods like ARIMA, which assume fixed-frequency observations, are desired but achieving consistent sample spacing is unattainable. This study investigated the applicability of Classification and Regression Tree (CART) regression as a practical alternative, using Minitab® Statistical Software, to model microbial density collected at irregular intervals. Three response variables were studied with respect to Elapsed Time: a sequential counter, cumulative untransformed microbial density, and cumulative log-transformed microbial density. CART could not model the sequential counter but succeeded with both cumulative variables. The log-transformed cumulative model achieved a test R-squared of 97.88% and a Mean Absolute Percent Error (MAPE) of 0.1610%. The cumulative untransformed model also performed well, with a test R-squared of 95.40% and MAPE of 0.5477 %. The transformed data yielded slightly better results. These findings show that CART regression with Elapsed Time robustly models cumulative trends in irregularly sampled data and is a valuable alternative when fixed-frequency model assumptions cannot be met.