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Three-dimensional printing of antidiabetic tablets
This study was conducted to employ the novel technology of three-dimensional printing as an alternative to conventional tableting technology in order to produce geometrically customizable tablet that offers personalized and tunable release profile. In addition to customization of release profile, geometrical design was utilized to enhance the dissolution of poorly water-soluble drug repaglinide from tablet dosage form. Semi-solid extrusion with a three-dimentional (3D) bioprinting machine (EnvisionTEC Bioplotter, Germany) was used as the production technology. Paste of traditional pharmaceutical excipients was formed by mixing powdered component and adding liquid binder. Lactose was used as a filler, PEG 6000 as a plasticizer, while different viscosity grades of hydroxypropylmethyl cellulose (HPMC,100K, and 15K mPa.s) served as release modifier polymers. Repaglinide was the antidiabetic active pharmaceutical ingredient (API) and the model for poorly water-soluble BCS class II drug. The liquid binder was formed as 0.5 % (w/v) gel of HPMC E4M in water, and added in a sufficient amount to create an extrudable, printable paste through a 0.41 mm nozzle. The tablets digital cylindrical design was created using Prefactory® RP program (EnvisionTEC, Germany), and then it was exported to the printer operating program VisualMachines. Two separate formulations were developed using HPMC 100K mPa.s and HPMC 15K mPa.s and, within each formulation, three different types of tablets were printed with strands distances (SD) parameter of 1.0, 1.3, and 1.6 mm (which determined the perforation levels within tablets). The resulting tablets were evaluated by their thickness, diameter, hardness, weight variation, friability, and dissolution profiles. The difference in these attributes were investigated in relation to their HPMC grades and 3D printing SD parameter. Overall, higher perforation levels in tablets and lower viscosity grades of HPMC produced higher rates of dissolution. Additionally, controlling perforations was also successful in enhancing the dissolution of the poorly water-soluble drug repaglinide. Hence, 3DP can be used to design tablets with customized release profiles to suit personalized medication with a 3D printer in clinical settings such as pharmacies and hospitals.
Formulation and characterization studies of sunscreen formulations
Constant exposure to ultraviolet (UV) radiation is an important cause of sunburn, inflammation, photoaging, and skin cancer, along other types of skin damage. The structure within the skin—specifically, the epidermis and melanin content—determines how sensitive the skin is to UV radiation. Preventing these negative consequences requires the use of effective photoprotection techniques such antioxidants, broad-spectrum sunscreens, and protective gear. In-vivo and in-vitro SPF testing techniques are commonly used to assess sunscreen performance, with UV-Vis spectrophotometry being a crucial component of the latter. The use, classification, and testing of UV filters and sunscreen actives are outlined in regulatory recommendations issued by agencies including the FDA, EU, and Asian authorities. This study concentrated on the formulation and assessment of a series of sunscreen emulsions that include chlorogenic acid, a natural antioxidant, as the primary active component, alongside various plant-derived oils (sesame seed, olive, pomegranate seed, rosemary) and UV filters such as titanium dioxide, zinc oxide, and octocrylene. Fourteen formulations were created and evaluated for SPF, pH (for skin compatibility), viscosity, density, FTIR spectra, physical stability, and in vitro release of chlorogenic acid using a Franz diffusion cell. The maximum SPF value (13.95) was recorded in formulation F14, which incorporated 10% octocrylene and 1.5% chlorogenic acid. Mineral filters alone provide moderate protection, but chlorogenic acid was shown to improve SPF mostly when combined with chemical filters. Multiple formulations (F2, F4, F5) were discarded due to instability. The research indicates that the integration of physical and chemical UV filters with natural antioxidants presents a viable strategy for creating effective, stable, and skin-compatible sunscreen compositions.
Development of thymoquinone-loaded nanoemulgel using black cumin (Nigella sativa L.) oil and extract for enhanced dermal delivery
Nigella sativa (black seed) is a medicinal plant widely recognized for its antioxidant, anti-inflammatory, and anticancer properties, primarily attributed to its bioactive constituent, thy-moquinone (TQ). However, TQ's poor aqueous solubility and instability limit its therapeutic ef-ficacy in topical applications. This study aimed to develop and characterize a thymoquinone-rich nanoemulgel system using n-hexane-extracted black seed oil and a polyphenol-rich ethanol extract to enhance cutaneous bioavailability and biological performance. Black seed oil was extracted using n-hexane (yield: 31.5%), and the ethanol extract yield-ed 11.25%. Four nanoemulsion formulations (1NP–4NP) were prepared using high-shear ho-mogenization with varying oil, extract, and surfactant ratios. Among them, the dual-loaded formulation 3NP demonstrated superior physicochemical properties, with a droplet size of ~50 nm, low polydispersity index (~0.2), and zeta potential of –25 mV, indicating colloidal stability. FTIR analysis confirmed chemical integrity and successful encapsulation of bioactives without degradation. HPLC and GC-FID quantification revealed that 3NP achieved high (TQ) loading (~240 µg/mL). HPTLC and antioxidant assays (DPPH, CUPRAC) confirmed the presence of multiple antioxidants and their synergistic action. The 3NP nanoemulgel formulated with NaCMC exhibited optimal viscosity, bioadhesion, and spreadability. In vitro release and ex vivo pig skin permeation studies demonstrated signifi-cantly enhanced TQ delivery from 3NP compared to other formulations. MTT cytotoxicity as-says revealed selective toxicity against melanoma cells, with minimal effect on normal fibro-blasts. These findings indicate strong therapeutic potential. In conclusion, the dual-phase Nigel-la sativa nanoemulgel (3NP) represents a promising platform for advanced topical cosmeceuti-cals, warranting further in vivo evaluation and long-term stability testing.
Development and evaluation of an alum-loaded gel with antimicrobial potential for the topical management of bacterial folliculitis
Bacterial folliculitis is a common skin disorder characterized by inflammation of hair follicles, primarily caused by Staphylococcus aureus, along with other Gram-positive and Gram-negative bacteria. Existing treatments mainly rely on topical and systemic antibiotics, whose effectiveness is increasingly compromised by resistance and side effects. Here we present a novel approach to the management of bacterial folliculitis, using for the first time an innovative formulation of potassium alum, a natural broad-spectrum antimicrobial and astringent, in the form of hydroxypropyl cellulose (HPC) gel. Hydrophilic gels were made with HPC and hydrated alum at 3, 4, and 5.5 % concentrations. The pH, viscosity, drug content and physical appearance of the formulations was determined. The in vitro antimicrobial activity was evaluated by disc diffusion method against panel of pathogens (S. aureus, E. faecalis, E. hirae, P. aeruginosa, A. baumannii, E. coli, and C. albicans). Release, permeation, and Kp were determined by in vitro and ex vivo (pig skin) Franz diffusion studies. Compatibility of the drug with the excipient was studied by FTIR spectroscopy. The anti-microbial action was dose related: 3% exerted no activity and 5% and 8% demonstrated a marked effect. The ex vivo permeation, Jss, and cumulative release data were the highest for gel 8% alum (G8). FTIR analysis showed no remarkable chemical interactions between alum and the excipients. In vitro efficacy of 5% suspension and 8% cream was moderate although ex vivo there was limited effect due to epidermal barrier activities. This is the first complete report of alum-loaded HPC gel in folliculitis, suggesting the 8% HPC gel to be a clinically novel non-antibiotic topical medicament. Keywords: Potassium alum, hydroxypropyl cellulose, topical gel, bacterial folliculitis, antimicrobial activity, Franz diffusion, FTIR, skin permeation.