Accelerated stability modeling of recrystallization from amorphous solid Dispersions: A Griseofulvin/HPMC-AS case study

Amorphous solid dispersions (ASDs) represent an important approach for enhancing oral bioavailability for poorly water soluble compounds; however, assuring that these ASDs do not recrystallize to a significant extent during storage can be time-consuming. Therefore, various efforts have been undertaken to predict ASD crystallization levels with kinetic models. However, only limited success has been achieved due to limits on crystal content quantification methods and the complexity of crystallization kinetics. To increase the prediction accuracy, the accelerated stability assessment program (ASAP), employing isoconversion (time to hit a specification limit) and a modified Arrhenius approach, are employed here for predictive shelf-life modeling. In the current study, a model ASD was prepared by spray drying griseofulvin and HPMC-AS-LF. This ASD was stressed under a designed combinations of temperature, relative humidity and time with the conditions set to ensure stressing was carried out below the glass transition temperature (Tg) of the ASD. Crystal content quantification method by X-ray powder diffraction (XRPD) with sufficient sensitivity was developed and employed for stressed ASD. Crystallization modeling of the griseofulvin ASD using ASAPprime® demonstrated good agreement with long-term (40 °C/75 %RH) crystallinity levels and support the use of this type of accelerated stability studies for further improving ASD shelf-life prediction accuracy.

Molecular insights into the formation of drug-polymer inclusion complex

Drug-polymer inclusion complex (IC) has been viewed as a novel solid form of drugs for property modification. Nonetheless, our understanding of the formation mechanism remains limited. This work aims to provide insight into the molecular processes governing the structural construction of carbamazepine (CBZ) and griseofulvin (GSF) channel-type ICs in the presence of guest polymers. Leveraging microdroplet melt crystallization, we successfully unveiled the single-crystal structures of these ICs, enabling structural analysis, density functional theory calculations, and molecular dynamics simulations. The results collectively elucidate the disparity between CBZ and GSF channels in terms of their autonomy in the absence of guest polymers. CBZ molecules can spontaneously assemble into stable channel structures independently, capitalizing on their unique mortise-tenon architecture and robust π…π interactions. Conversely, GSF channels lack sufficient support from weak Cl…O and C-H…π intermolecular interactions and necessitate the insertion of guest molecules to stabilize their structures. We further calculated the eleven structurally determined drug-polymer ICs and found that their channel sizes consistently fall within a narrow range of 3.81-5.18 Å although they adopt diverse approaches to construct channel structures. We anticipate that these findings will inspire continued exploration of this novel solid form, facilitating theoretical predictions and practical applications in pharmaceutical development.

QQYB1

Marine microorganisms have long been recognized as potential sources for drug discovery. Griseofulvin was one of the first antifungal natural products and has been used as an antifungal agent for decades. In this study, 12 new griseofulvin derivatives [(±)-1-2, (+)-3, (±)-4, 10-12, and 14-15] and two new griseofulvin natural products (9 and 16) together with six known analogues [(-)-3, 5-8, and 13] were isolated from the mangrove-derived fungus Nigrospora sp. QQYB1 treated with 0.3% NaCl or 2% NaBr in rice solid medium. Their 2D structures and absolute configurations were established by extensive spectroscopic analysis (1D and 2D NMR, HRESIMS), ECD spectra, computational calculation, DP4 + analysis, and X-ray single-crystal diffraction. Compounds 1-4 represent the first griseofulvin enantiomers with four absolute configurations (2S, 6'S; 2R, 6'R; 2S, 6'R; 2R, 6'S), and compounds 9-12 represent the first successful production of brominated griseofulvin derivatives from fungi via the addition of NaBr to the culture medium. In the antifungal assays, compounds 6 and 9 demonstrated significant inhibitory activities against the fungi Colletotrichum truncatum, Microsporum gypseum, and Trichophyton mentagrophyte with inhibition zones varying between 28 and 41 mm (10 μg/disc). The structure-activity relationship (SAR) was analyzed, which showed that substituents at C-6, C-7, C-6' and the positions of the carbonyl and double bond of griseofulvin derivatives significantly affected the antifungal activity.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42995-023-00210-0.

Three Cases of Recalcitrant Pediatric Tinea Capitis Successfully Treated with Griseofulvin

Tinea capitis is an infection of the scalp hair follicles and surrounding skin that primarily occurs in prepubertal children. Microsporum canis remains the most common pathogen causing tinea capitis in Asian countries, including South Korea, although the causative organism of this condition varies across geographical regions and time periods. Systemic antifungal agents are the mainstay treatments for tinea capitis; however, the therapeutic responses to antifungal drugs may vary depending on the causative species, and treatment failure may occur owing to drug resistance. Although dermatophytosis resistant to clinical treatment have been increasingly encountered, recalcitrant tinea capitis cases have rarely been reported. Herein, we report three cases of tinea capitis caused by M. canis in children. All three patients showed unsatisfactory clinical responses to prolonged courses of oral terbinafine or itraconazole without achieving mycological cure; however, they were successfully treated with oral griseofulvin. Although griseofulvin is not currently available or licensed for use in many countries, including South Korea, it is one of the most effective agents against Microsporum species and remains the most widely used first-line treatment for tinea capitis in children, based on dermatology textbooks and reliable treatment guidelines.

Griseofulvin analogues from the fungus Penicillium griseofulvum and their anti-inflammatory activity

Six griseofulvin analogues named penigriseofulvins A - F (1-6), including three undescribed compounds and three undescribed natural products, were isolated from the fungus Penicillium griseofulvum. Their structures and absolute configurations were determined by NMR spectroscopic analyses, HRESIMS, and X-ray diffraction experiments. All compounds were evaluated for their anti-inflammatory activity, of which compounds 1 and 4 showed potential anti-inflammatory effects in RAW264.7 macrophages and ulcerative colitis mice.

Neonatal-Onset Inflammatory Tinea Capitis by Microsporum canis Due to a Woolen Hat

Tinea capitis is a common fungal infection in children, but it is rare in newborns. We report a case of a 3-week-old infant presenting with scalp annular erythema. She had a history of wearing a woolen hat one week before the disease onset. Wood's lamp and dermoscopic findings favoured the diagnosis of tinea capitis. Further examinations of her scalp, including direct KOH examination and fungal culture confirmed the diagnosis of tinea capitis caused by treatment with oral griseofulvin was effective. Neonatal tinea capitis is often misdiagnosed due to its rarity and atypical presentation. A thorough history (including the contacting history of clothes made of animal fur), physical examination and further mycological examinations are required for diagnosis. Griseofulvin, itraconazole and fluconazole have been reported to be effective drugs for the treatment of children tinea capitis. Liver enzymes should be regularly monitored during the period of using antifungal agents.

Preparation and Evaluation of a Microsponge Dermal Stratum Corneum Retention Drug Delivery System for Griseofulvin

Griseofulvin (GF) is used as an antifungal to treat superficial skin fungal infections such as tinea capitis and tinea pedis. Currently, GF is only available in traditional oral dosage forms and suffers from poor and highly variable bioavailability, hepatotoxicity, and long duration of treatment. Therefore, the main objective of this study was to reduce the side effects of the drug and to increase the concentration of the drug retained in the cutaneous stratum corneum (SC) and improve its efficacy through the preparation of drug-laden GF microsponge (GFMS). The emulsification-solvent-diffusion method was used to prepare GFMS, and the prescriptions were screened by a single-factor approach. The optimized formulation (GFF8) had a microsponge particle size (μm) of 28.36 ± 0.26, an encapsulation efficiency (%) of 87.53 ± 1.07, a yield (%) of 86.58 ± 0.42, and drug release (%) from 77.57 ± 3.88. The optimized microsponge formulation was then loaded into a Carbopol 934 gel matrix and skin retention differences between the microsponge gel formulation and normal gels were examined by performing skin retention and fluorescence microscopy tests. Finally, the hepatoprotective and cutaneous stratum corneum retention abilities of microsponge gel formulations compared to oral GF formulations were assessed by hepatotoxicity, pharmacokinetics, and tissue distribution studies. This provides a new perspective on GF dermal stratum corneum retention administration.

Small scale in vitro method to determine a bioequivalent equilibrium solubility range for fasted human intestinal fluid

Drug solubility is a key parameter controlling oral absorption, but intestinal solubility is difficult to assess in vitro. Human intestinal fluid (HIF) aspirates can be applied but they are variable, difficult to obtain and expensive. Simulated intestinal fluids (SIF) are a useful surrogate but multiple recipes are available and the optimum is unknown. A recent study characterised fasted HIF aspirates using a multi-dimensional approach and determined nine bioequivalent SIF media recipes that represented over ninety percent of HIF compositional variability. In this study these recipes have been applied to determine the equilibrium solubility of twelve drugs (naproxen, indomethacin, phenytoin, piroxicam, aprepitant, carvedilol, zafirlukast, tadalafil, fenofibrate, griseofulvin, felodipine, probucol) previously investigated using a statistical design of experiment (DoE) approach. The bioequivalent solubility measurements are statistically equivalent to the previous DoE, enclose literature solubility values in both fasted HIF and SIF, and the solubility range is less than the previous DoE. These results indicate that the system is measuring the same solubility space as literature systems with the lower overall range suggesting improved equivalence to in vivo solubility, when compared to DoEs. Three drugs (phenytoin, tadalafil and griseofulvin) display a comparatively narrow solubility range, a behaviour that is consistent with previous studies and related to the drugs' molecular structure and properties. This solubility behaviour would not be evident with single point solubility measurements. The solubility results can be analysed using a custom DoE to determine the most statistically significant factor within the media influencing solubility. This approach has a lower statistical resolution than a formal DoE and is not appropriate if determination of media factor significance for solubilisation is required. This study demonstrates that it is possible to assess the fasted intestinal equilibrium solubility envelope using a small number of bioequivalent media recipes obtained from a multi-dimensional analysis of fasted HIF. The derivation of the nine bioequivalent SIF media coupled with the lower measured solubility range indicate that the solubility results are more likely to reflect the fasted intestinal solubility envelope than previous DoE studies and highlight that intestinal solubility is a range and not a single value.

[Kerion Celsi due to Microsporum canis infection]

Tinea capitis is seen world-wide among children up to 12 years. The most severe type is Kerion Celsi with painful abscesses and lymphadenopathy. We report on an 11-year-old boy with Kerion Celsi, who was initially treated using antibiotics under the common misdiagnosis of a bacterial infection. Mycological investigations could identify Microsporum canis. The patient was treated orally with griseofulvin, which resulted in complete mycological remission after 8 weeks. Cicatrical alopecia, however, could not be prevented. Purulent infections of the scalp should lead to early mycological diagnostics in children.

[Tinea capitis: clinical features and therapeutic alternatives]

A descriptive observational and cross-sectional study was carried out. The clinical characteristics, etiologic agents, treatments and outcome of 33 cases of tinea capitis in the Mycology Unit at Francisco J. Muñiz Hospital of Buenos Aires City between January 2015 and December 2019 were analyzed. The median age of the patients was 7 years, 21 of whom were male, 3 were HIV-positive and 22 had pets. The isolated etiologic agents were the following: Microsporum canis in 22 cases, Trichophyton tonsurans in 8, Nannizzia gypsea in 2 and Trichophyton mentagrophytes in one patient. Suppurative tinea capitis (krion Celsi) was detected in 10 cases and the same number of patients presented other skin locations of their dermatophytosis in addition to those in the scalp. Twenty-one cases were orally treated with griseofulvin and 12 with terbinafine. Those patients with suppurative tinea capitis received drops of betamethasone by mouth besides the antifungal drugs. All patients had good clinical and mycological response to the treatments, all lesions disappeared, and mycological studies turned negative by the end of the treatments. We conclude that both drugs were effective for the treatment of tinea capitis; however, lesions in those cases receiving terbinafine involuted more slowly.

Enhancing the Antifungal Activity of Griseofulvin by Incorporation a Green Biopolymer-Based Nanocomposite

Fungal biofilms have caused several medical problems, resulting in significant morbidity and mortality as well as poor response to antifungal drugs. The current study was designed to evaluate the enhancement of antifungal and anti-biofilm activity of Griseofulvin-loaded green nanocomposite-based biopolymers (Ge-Nco) of glycogen and gelatin against different strains of pathogenic Candida species. The prepared Ge-Nco was characterized using Fourier-transform infrared (FT-IR), X-ray diffraction pattern (XRD), scanning electron microscopy-energy dispersive X-ray (SEM-EDX) and transmission electron microscope (TEM). In addition, the morphology of the mature biofilm and the inhibition of biofilm was monitored and visualized using confocal laser scanning microscopy (CLSM). The minimal inhibitory concentrations (MIC) and (IC50) of Griseofulvin alone and the prepared Ge-Nco against three different strains of Candida sp. were determined according to Clinical and Laboratory Standards Institute (CLSI) method. The effects of Griseofulvin alone and Ge-Nco on the tested Candida sp. biofilm formation were determined by the crystal-violet staining protocol. The biofilm inhibition potential of Ge-Nco against the tested Candida sp. was detected and depicted under CLSM (2.5 D view). The findings depicted that Ge-Nco was prepared in nanometer size (10–23 nm). The observed minimum inhibitory concentration (MIC) of Griseofulvin alone and Ge-Nco against three different Candida sp. were found to be in range 49.9–99.8 μg/mL and 6.24–12.48 μg/mL, respectively. These results provide evidence for implementing efficient antivirulence approaches against three different Candida sp. that would be less likely to foster the emergence of resistance.

rubrum: Mechanisms of action and efficiency compared to griseofulvin and itraconazole

AIMS

According to the WHO, 20-25% of people worldwide are affected by skin infections caused by dermatophytes, such as those of the Trichophyton genus. Additionally, several dermatophytes have developed resistance to drugs such as griseofulvin and itraconazole. This study tested 2S albumins-derived antimicrobial peptides (AMPs) as alternative antidermatophytic molecules.

MAIN METHODS

Membrane pore formation assays, tests to detect overproduction of ROS, scanning electron microscopy (SEM) and fluorescence microscopy (FM) were carried out to provide insight into the mechanisms of antidermatophytic action.

KEY FINDINGS

All AMPs (at 50 μg mL^-1) tested reduced the mycelial growth of T. mentagrophytes and T. rubrum by up to 95%. In contrast, using a concentration 20-fold higher, griseofulvin only inhibited T. mentagrophytes by 35%, while itraconazole was not active against both dermatophytes. Scanning electron and fluorescence microscopies revealed that the six AMPs caused severe damage to hyphal morphology by inducing cell wall rupture, hyphal content leakage, and death. Peptides also induced membrane pore formation and oxidative stress by overproduction of ROS. Based on the stronger activity of peptides than the commercial drugs and the mechanism of action, all six peptides have the potential to be either employed as models to develop new antidermatophytic drugs or as adjuvants to existing ones.

SIGNIFICANCE

The synthetic peptides are more efficient than conventional drug to treat infection caused by dermatophytes being potential molecules to develop new drugs.

Antisolvent precipitative immobilization of micro and nanostructured griseofulvin on laboratory cultured diatom frustules for enhanced aqueous dissolution

We report for the first time an antisolvent synthesis of nanostructured hydrophobic drug formulation onto a natural diatom. The jewel of the sea, a marine diatom, which is enriched in silicon, was cultured and grown in the laboratory. Its frustules were isolated and purified. The polar functional group on its surface provided unique physical and chemical properties. Griseofulvin (GF), an antifungal drug was used as a model compound was precipitated onto and adsorbed onto hydrophilic diatom surface, while stabilizer hydroxypropyl methyl cellulose (HPMC) was used for restricting particle growth during the composite synthesis. This work demonstrates that the fine drug crystals incorporated onto the diatom silica surface. The structural and morphological properties of the drug was characterized by various techniques. The drug loading of the formulation was estimated to be 41 % by weight. The incorporation of micro/nano crystals on the diatom surface dramatically enhanced the dissolution rate, and lowered the time required for 50 % dissolution for pure drug from 240-58 min for the drug composite, and the time required for 80 % dissolution or T₈₀ was found to be 180 min for the composite while the pure drug reached a maximum of 65 % in 300 min.

Continuous synthesis of drug nanocrystals by solid hollow fiber cooling crystallization

Size reduction of drug with poor water solubility to nanoscale is an effective way to help improve the efficacy of drug delivery to the human body. A solid hollow fiber cooling crystallization technique has been adopted to continuously produce griseofulvin drug nanoparticles under modest conditions with accurate controllability. In the solid hollow fiber cooling crystallization device, drug solution flowed through the bores of solid hollow fibers while the cooling liquid was circulated counter-currently in the shell side of the device to cool down the drug solution in the tube side. Due to intense heat exchange between the cooling liquid and the drug solution through the thin fiber walls, the temperature of drug solution decreased rapidly so that drug nanoparticles were precipitated out from the solution by sudden reduction of solubility. Through variation of the experimental conditions and parameters, the mean size of the produced nanoparticles was regulated and controlled. The nanoparticles were dispersed uniformly, the chemical structure and bonds of prepared nanoparticles was the same with as-received griseofulvin. Both raw material and NPs the polymorph(s) present form I, the melting point was 220 °C. Drug dissolution testing was also executed to verify that nanocrystals have a higher dissolution profile.

Formulation and evaluation of cyclodextrin-based nanosponges of griseofulvin as pediatric oral liquid dosage form for enhancing bioavailability and masking bitter taste

The aim of this study was the development of griseofulvin (GRI) loaded β-cyclodextrin (β–CD) based nanosponges for bitter taste masking, improving dissolution rate and oral bioavailability. Plain NS (NS1 NS2 and NS3) were fabricated by reacting β-CD with the cross-linker diphenyl carbonate at different molar ratios (1:2, 1:4 and 1:6, respectively) using ultrasonication method. The NS2 provided both highest %yield and GRI solubilization enhancement. Thus, the drug was loaded in NS2 at different NS2: drug weight ratios in presence or absence of 0.25%w/w polyvinylpyrolidone (PVP k30). The GRI loaded NS (F1) that provided highest drug loading capacity and entrapment efficiency (47.20 ± 0.38%, 84.91 ± 0.30%, respectively) was morphologically examined using scanning electron microscopy (SEM). Also, Particle size, zeta potential, differential scanning calorimetry (DSC), Fourier transform infra-red (FT-IR), nuclear magnetic resonance (NMR) spectroscopy, in-vitro release, taste masking potential were evaluated. Moreover, in-vivo Pharmacokinetic studies were performed on rats. The F1 showed particle size 665.9 ± 13.8 nm and zeta potential −21.5 ± 0.7 mV. The DSC and FT-IR analysis confirmed the complexation of GRI with NS2. Nanosponges (F1) provided 3.19, folds increase in dissolution efficiency %, 2.13 and 3.78 folds increase in C_max and AUC_0-48 compared to plain GRI. Taste masking evaluation confirmed the potential of GRI nanosponges (F1) in masking the bitter taste of GRI completely. The study confirmed that complexation of GRI with NS would be a viable approach for masking the bitter taste of GRI and improving oral bioavailability, that Cmax, Tmax and AUC 0–48 were significantly higher for the developed formulation (F1).

Antibacterial activity of griseofulvin analogues as an example of drug repurposing

Griseofulvin is a well-known antifungal drug that was launched in 1962 by Merck & Co. for the treatment of dermatophyte infections. However, according to predictions using the Way2Drug computational drug repurposing platform, it may also have antibacterial activity. As no confirmation of this prediction was found in the published literature, this study estimated in-silico antibacterial activity for 42 griseofulvin derivatives. Antibacterial activity was predicted for 33 of the 42 compounds, which led to the conclusion that this activity might be considered as typical for this chemical series. Therefore, experimental testing of antibacterial activity was performed on a panel of Gram-positive and Gram-negative micro-organisms. Antibacterial activity was evaluated using the microdilution method detecting the minimal inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC). The tested compounds exhibited potent antibacterial activity against all the studied bacteria, with MIC and MBC values ranging from 0.0037 to 0.04 mg/mL and from 0.01 to 0.16 mg/mL, respectively. Activity was 2.5-12 times greater than that of ampicillin and 2-8 times greater than that of streptomycin, which were used as the reference drugs. Similarity analysis for all 42 compounds with the (approximately) 470,000 drug-like compounds indexed in the Clarivate Analytics Integrity database confirmed the significant novelty of the antibacterial activity for the compounds from this chemical class. Therefore, this study demonstrated that by using computer-aided prediction of biological activity spectra for a particular chemical series, it is possible to identify typical biological activities which may be used for discovery of new applications (e.g. drug repurposing).

First report of tinea corporis caused by Arthroderma benhamiae in Brazil

Arthroderma benhamiae is a zoophilic dermathophyte that can cause highly inflammatory tinea corporis and tinea capitis in humans. This is the first report of a patient with dermatophytosis caused by A. benhamiae in Brazil. The lesion was an erythematous, annular plaque on the lumbar region that appeared few weeks after playing with a street cat in a 19-month-old girl. Initial presumed diagnosis was tinea corporis caused by Microsporum canis. Topical treatments were ineffective and the patient required systemic treatment with griseofulvin. Mycological diagnosis was inconclusive: morphological differentiation between M. canis and Trichophyton benhamiae may be difficult, especially when the latter present yellow colonies. The etiological agent was identified only by ITS sequencing of the isolates aligned with reference strains to A. benhamiae. This report highlights the importance of ITS sequencing in the identification of isolates from some cases of dermatophytosis, because conventional morphological diagnosis may result in misdiagnosis of the agent and delay proper treatment.

Clinico-mycological profile of tinea capitis and its comparative response to griseofulvin versus terbinafine

Background and Purpose:

Tinea capitis is the most common superficial mycosis in children. This disease is a contagious infection with worldwide distribution and is occasionally associated with permanent alopecia. The treatment of this infection usually requires the administration of appropriate oral antifungal agents. The current study was conducted to evaluate the clinico-mycological profile of tinea capitis and compare the efficiency of oral griseofulvin and terbinafine in the treatment of this disease.

Materials and Methods:

This study was conducted on 69 patients, including 23 females (33.3%) and 46 males (66.7%), clinically suspected of tinea capitis. After the confirmation of tinea capitis diagnosis through direct examination, the subjects were randomly assigned into two groups of griseofulvin and terbinafine. Demographic data, clinical and mycological characteristics, and therapeutic outcome were recorded for both groups.

Results:

According to the results, tinea capitis was more common in children younger than 15 years (73.9%), athletes (37.7%), and males (66.7%), and those with frontal involvement (34.8%), non-inflammatory type (68.1%), endothrix (69.6%), and Trichophyton tonsurans species (41.7%). The griseofulvin and terbinafine groups had the treatment success rates of 90.9% and 80.6%, respectively (P=0.311). The griseofulvin group had a shorter therapeutic course than the terbinafine group (P=0.129).

Conclusion:

Although our findings demonstrated that both griseofulvin and terbinafine were effective in the treatment of tinea capitis, griseofulvin showed a little higher efficacy in this regard. Consideration of some variables, such as age, associated risk factors, clinical type, hair involvement pattern, and dominant pathogenic species, is important in the determination of the drugs.

Griseofulvin Efficiently Induces Apoptosis in In Vitro Treatment of Lymphoma and Multiple Myeloma

BACKGROUND/AIM

Recent innovations in the development of systemic and targeted therapies have improved survival and quality of life in multiple myeloma (MM) patients. However, in most cases, this hematological malignancy of monoclonal B-lymphocytes remains incurable. Exaggerated Wnt/β-catenin signaling has been demonstrated in lymphoma and MM, therefore targeting related signaling molecules might represent a promising therapy approach. Griseofulvin, a widely used antifungal drug, is chemically related to other known Wnt-inhibitors and we recently demonstrated its potent in vivo efficacy in a murine myeloma model.

MATERIALS AND METHODS

The anti-tumor apoptotic effect of griseofulvin at doses ranging from 0.1-200 μM was investigated on a total of ten human and two murine myeloma/lymphoma cell lines, as determined by 3'3-dihexyloxacarbocyanine iodide (DiOC6) and propidium iodide (PI) staining in flow cytometry.

RESULTS

Griseofulvin significantly induced apoptosis in all investigated myeloma and lymphoma cell lines in a dose-dependent manner, while healthy control cells were less sensitive.

CONCLUSION

Given the known safety profile and apoptosis induction at low effective doses, our data warrant further in vitro and in vivo studies utilizing griseofulvin as a potential therapy agent for MM and lymphoma.

Chemoselective fluorination and chemoinformatic analysis of griseofulvin: Natural vs fluorinated fungal metabolites

Griseofulvin is a fungal metabolite and antifungal drug used for the treatment of dermatophytosis in both humans and animals. Recently, griseofulvin and its analogues have attracted renewed attention due to reports of their potential anticancer effects. In this study griseofulvin (1) and related analogues (2-6, with 4 being new to literature) were isolated from Xylaria cubensis. Six fluorinated analogues (7-12) were synthesized, each in a single step using the isolated natural products and Selectflour, so as to examine the effects of fluorine incorporation on the bioactivities of this structural class. The isolated and synthesized compounds were screened for activity against a panel of cancer cell lines (MDA-MB-435, MDA-MB-231, OVCAR3, and Huh7.5.1) and for antifungal activity against Microsporum gypseum. A comparison of the chemical space occupied by the natural and fluorinated analogues was carried out by using principal component analysis, documenting that the isolated and fluorinated analogues occupy complementary regions of chemical space. However, the most active compounds, including two fluorinated derivatives, were centered around the chemical space that was occupied by the parent compound, griseofulvin, suggesting that modifications must preserve certain attributes of griseofulvin to conserve its activity.

Preparation and Microstructural Characterization of Griseofulvin Microemulsions Using Different Experimental Methods: SAXS and DSC

Purpose: The objective of the present study is to formulate and evaluate a new microemulsion (ME) for topical delivery of griseofulvin.

Methods: The solubilities of griseofulvin in different combinations of surfactant to co-surfactant (S/Co ratio) were determined. Accordingly, based on their phase diagrams, eight microemulsions were formulated and then evaluated with respect to their particle size, surface tension, viscosity, conductivity, zeta potential and stability. Their release behavior, Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), refractory index (RI), pH and Small-angle-X-ray scattering (SAXS) were also assessed.

Results: The results indicated that the mean droplet size of the MEs ranged from 30.9 to 84.3 nm. Their zeta potential varied from -4.5 to -20.8. Other determined characteristics were viscosity: 254-381 cps, pH: 5.34-6.57, surface tension: 41.16- 42.83 dyne.cm^-1, conductivity: 0.0442 – 0.111 ms.cm^-1. The drug release was in the range of 22.4 to 43.69 percent. Also, hexagonal, cubic and lamellar liquid crystals were observed in SAXS experiments.

Conclusion: It can be concluded that any alteration in MEs constituents directly affects their microstructure, shape, droplet size and their other physicochemical properties.

Synthesis and formulation studies of griseofulvin analogues with improved solubility and metabolic stability

Griseofulvin (1) is an important antifungal agent that has recently received attention due to its antiproliferative activity in mammalian cancer cells. Comprehensive SAR studies have led to the identification of 2'-benzyloxy griseofulvin 2, a more potent analogue with low micromolar anticancer potency in vitro. Analogue 2 was also shown to retard tumor growth through inhibition of centrosomal clustering in murine xenograft models of colon cancer and multiple myeloma. However, similar to griseofulvin, compound 2 exhibited poor metabolic stability and aqueous solubility. In order to improve the poor pharmacokinetic properties, 11 griseofulvin analogues were synthesized and evaluated for biological activity and physiological stabilities including SGF, plasma, and metabolic stability. Finally, the most promising compounds were investigated in respect to thermodynamic solubility and formulation studies. The 2'-benzylamine analogue 10 proved to be the most promising compound with low μM in vitro anticancer potency, a 200-fold increase in PBS solubility over compound 2, and with improved metabolic stability. Furthermore, this analogue proved compatible with formulations suitable for both oral and intravenous administration. Finally, 2'-benzylamine analogue 10 was confirmed to induce G2/M cell cycle arrest in vitro.

Preparation and Optimization OF Palm-Based Lipid Nanoparticles Loaded with Griseofulvin

Palm-based lipid nanoparticle formulation loaded with griseofulvin was prepared by solvent-free hot homogenization method. The griseofulvin loaded lipid nanoparticles were prepared via stages of optimisation, by altering the high pressure homogenisation (HPH) parameters, screening on palm-based lipids and Tween series surfactants and selection of lipid to surfactant ratios. A HPLC method has been validated for the drug loading capacity study. The optimum HPH parameter was determined to be 1500 bar with 5 cycles and among the palm-based lipid materials; Lipid C (triglycerides) was selected for the preparation of lipid nanoparticles. Tween 80 was chosen from the Tween series surfactants for its highest saturated solubility of griseofulvin at 53.1 ± 2.16 µg/mL. The optimum formulation of the griseofulvin loaded lipid nanoparticles demonstrated nano-range of particle size (179.8 nm) with intermediate distribution index (PDI) of 0.306, zeta potential of -27.9 mV and drug loading of 0.77%. The formulation was stable upon storage for 1 month at room temperature (25 ^°C) and 45 ^°C with consistent drug loading capacity.

Influence of the Encapsulation Efficiency and Size of Liposome on the Oral Bioavailability of Griseofulvin-Loaded Liposomes

The objective of the present study was to investigate the influence of the encapsulation efficiency and size of liposome on the oral bioavailability of griseofulvin-loaded liposomes. Griseofulvin-loaded liposomes with desired characteristics were prepared from pro-liposome using various techniques. To study the effect of encapsulation efficiency, three preparations of griseofulvin, namely, griseofulvin aqueous suspension and two griseofulvin-loaded liposomes with different amounts of griseofulvin encapsulated [i.e., F1 (32%) and F2(98%)], were administered to rats. On the other hand, to study the effect of liposome size, the rats were given three different griseofulvin-loaded liposomes of various sizes, generated via different mechanical dispersion techniques [i.e., FTS (142 nm), MS (357 nm) and NS (813 nm)], but with essentially similar encapsulation efficiencies (about 93%). Results indicated that the extent of bioavailability of griseofulvin was improved 1.7–2.0 times when given in the form of liposomes (F1) compared to griseofulvin suspension. Besides that, there was an approximately two-fold enhancement of the extent of bioavailability following administration of griseofulvin-loaded liposomes with higher encapsulation efficiency (F2), compared to those of F1. Also, the results showed that the extent of bioavailability of liposomal formulations with smaller sizes were higher by approximately three times compared to liposomal formulation of a larger size. Nevertheless, a further size reduction of griseofulvin-loaded liposome (≤400 nm) did not promote the uptake or bioavailability of griseofulvin. In conclusion, high drug encapsulation efficiency and small liposome size could enhance the oral bioavailability of griseofulvin-loaded liposomes and therefore these two parameters deserve careful consideration during formulation.

Ethosomes for enhanced skin delivery of griseofulvin

Griseofulvin (GRF) is an important antifungal drug with low bioavailability and, for this reason, a topical formulation with a targeted action and minimal systemic effects, appears to be a preferable solution. GRF poor solubility has limited the development of topical formulations and their release to the market. The aim of this work was to prepare a new GRF formulation for topical application using lipid-based nanosystems; to study its permeation and penetration, cell viability and to evaluate its therapeutic action. Ethosomal systems composed of soy bean phosphatidylcholine, ethanol and water were prepared for incorporating GRF. After the characterization of the vesicles in terms of size, charge and penetrability, permeation through newborn pig using Franz diffusion cells was conducted. Cell viability at different concentrations of the chosen formulation was determined. At last, skin adapted agar diffusion test was performed to assess the therapeutic efficacy of the formulation. GRF vesicles had mean size of 130nm. Permeation and penetration assays revealed that GRF-loaded ethosomes have an adequate profile to be used in a topical formulation since drug retention in the stratum corneum was achieved. Cell viability tests proved this formulation presented no cytotoxicity to HaCaT cells for concentrations below 50μg/mL. The skin diffusion test evidenced the potential of developed formulation to target skin dermatophytes. The results obtained in this study contribute to a new perspective in topical treatment of fungal infections.

Influence of spray drying and dispersing agent on surface and dissolution properties of griseofulvin micro and nanocrystals

The purpose for the current research is to compare and evaluate physiochemical properties of spray-dried (SD) microcrystals (MCs), nanocrystals (NCs), and nanocrystals with a dispersion agent (NCm) from a poorly soluble compound. The characterization was carried out by performing size and surface analysis, interfacial tension (at particle moisture interface), and in-vitro drug dissolution rate experiments. Nanosuspensions were prepared by media milling and were spray-dried. The SD powders that were obtained were characterized morphologically using scanning electron microscopy (SEM), polarized light microscopy (PLM), and Flowchem. Solid-state characterization was performed using X-ray powder diffraction (XRPD), Fourier transfer infrared spectroscopy (FT-IR), and differential scanning calorimetry (DSC) for the identification of the crystalline nature of all the SD powders. The powders were characterized for their redispersion tendency in the water and in pH 1.2. Significant differences in redispersion were noted for both the NCs in both dissolution media. The interfacial tension for particle moisture interface was determined by applying the BET (Braunauer-Emmett-Teller) equation to the vapor sorption data. No significant reduction in the interfacial tension was observed between MCs and NCs; however, a significant reduction in the interfacial tension was observed for NCm at both 25 °C and 35 °C temperatures. The difference in interfacial tension and redispersion behavior can be attributed to a difference in the wetting tendency for all the SD powders. The dissolution studies were carried out under sink and under non-sink conditions. The non-sink dissolution approach was found suitable for quantification of the dissolution rate enhancement, and also for providing the rank order to the SD formulations.

[Severe cutaneous drug reactions to misused griseofulvin: 2 cases]

BACKGROUND

Griseofulvin is an antifungal drug known to cause drug rash. However, it is widely prescribed outside its classic indications. Herein, we describe 2 cases in which griseofulvin was prescribed for off-label indications.

PATIENTS AND METHODS

Case No. 1. A 51-year-old woman was referred to the department of internal medicine for management of Stevens-Johnson Syndrome (SJS). The symptoms appeared 17 days after she had taken griseofulvin for inguinal intertrigo. Case No. 2. A 19-year-old female patient consulted for toxic epidermal necrolysis (TEN) affecting 30% of her body surface, with a positive Nikolsky sign and severe mucosal lesions. These symptoms appeared 9 days after she began taking griseofulvin, which had initially been prescribed for her husband for mycosis.

DISCUSSION

Toxic epidermal necrolysis, a condition chiefly of drug-related origin, is a severe mucocutaneous syndrome characterized by massive keratinocytic apoptosis. Although there are few scientific publications referring to griseofulvin-induced drug eruption, they deserve to be mentioned since this drug is widely used for purposes other than the approved indications and can cause life-threatening reactions.

CONCLUSION

We report two cases of toxic epidermal necrolysis related to the misuse of griseofulvin. It is important to bear in mind the precautions for use of oral antifungal drugs, which are strictly reserved for use against resistant or diffuse forms of mucocutaneous fungal infections.

A metabolomic perspective of griseofulvin-induced liver injury in mice

Griseofulvin (GSF) causes hepatic porphyria in mice, which mimics the liver injury associated with erythropoietic protoporphyria (EPP) in humans. The current study investigated the biochemical basis of GSF-induced liver injury in mice using a metabolimic approach. GSF treatment in mice resulted in significant accumulations of protoporphyrin IX (PPIX), N-methyl PPIX, bile acids, and glutathione (GSH) in the liver. Metabolomic analysis also revealed bioactivation pathways of GSF that contributed to the formation of GSF-PPIX, GSF-GSH and GSF-proline adducts. GSF-PPIX is the precursor of N-methyl PPIX. A six-fold increase of N-methyl PPIX was observed in the liver of mice after GSF treatment. N-methyl PPIX strongly inhibits ferrochelatase, the enzyme that converts PPIX to heme, and leads to PPIX accumulation. Excessive PPIX in the liver results in bile duct blockage and disturbs bile acid homeostasis. The accumulation of GSH in the liver was likely due to Nrf2-mediated upregulation of GSH synthesis. In summary, this study provides the biochemical basis of GSF-induced liver injury that can be used to understand the pathophysiology of EPP-associated liver injury in humans.

Tinea Imbricata in an Italian Child and Review of the Literature

Tinea imbricata is a chronic superficial mycosis caused by Trichophyton concentricum. It is characterized by widespread, annular, concentric, squamous lesions. Tinea imbricata is endemic in three geographical areas: Southwest Pacific, Southeast Asia, and Central and South America. Tinea imbricata in travelers returning from endemic areas is exceptionally rare. We report a case of tinea imbricata in an Italian child who acquired the infection during a trip to Solomon Islands. Three cultures were positive for T. concentricum. The patient was successfully treated with griseofulvin and terbinafine cream.

Nanomechanical testing technique for millimeter-sized and smaller molecular crystals

Large crystals are used as a control for the development of a mounting and nanoindentation testing technique for millimeter-sized and smaller molecular crystals. Indentation techniques causing either only elastic or elastic-plastic deformation produce similar results in assessing elastic modulus, however, the elastic indents are susceptible to surface angle and roughness effects necessitating larger sample sizes for similar confidence bounds. Elastic-plastic indentations give the most accurate results and could be used to determine the different elastic constants for anisotropic materials by indenting different crystal faces, but not by rotating the indenter about its axis and indenting the same face in a different location. The hardness of small and large crystals is similar, suggesting that defect content probed in this study is similar, and that small crystals can be compared directly to larger ones. The Young's modulus and hardness of the model test material, griseofulvin, are given for the first time to be 11.5GPa and 0.4GPa respectively.

Anti-Neoplastic Cytotoxicity of Gemcitabine-(C4-amide)-[anti-HER2/neu] in Combination with Griseofulvin against Chemotherapeutic-Resistant Mammary Adenocarcinoma (SKBr-3)

Introduction

Gemcitabine is a pyrimidine nucleoside analog that becomes triphosphorylated and in this form it competitively inhibits cytidine incorporation into DNA strands. Diphosphorylated gemcitabine irreversibly inhibits ribonucleotide reductase thereby preventing deoxyribonucleotide synthesis. Functioning as a potent chemotherapeutic, gemcitabine decreases neoplastic cell proliferation and induces apoptosis which accounts for its effectiveness in the clinical treatment of several leukemia and carcinoma cell types. A brief plasma half-life due to rapid deamination, chemotherapeuticresistance and sequelae restricts gemcitabine utility in clinical oncology. Selective “targeted” gemcitabine delivery represents a molecular strategy for prolonging its plasma half-life and minimizing innocent tissue/organ exposure.

Methods

A previously described organic chemistry scheme was applied to synthesize a UV-photoactivated gemcitabine intermediate for production of gemcitabine-(C₄-amide)-[anti-HER2/neu]. Immunodetection analysis (Western-blot) was applied to detect the presence of any degradative fragmentation or polymerization. Detection of retained binding-avidity for gemcitabine-(C₄-amide)-[anti-HER2/neu] was determined by cell-ELISA using populations of chemotherapeutic-resistant mammary adenocarcinoma (SKBr-3) that highly over-express the HER2/neu trophic membrane receptor. Anti-neoplastic cytotoxicity of gemcitabine-(C₄-amide)-[anti-HER2/neu] and the tubulin/microtubule inhibitor, griseofulvin was established against chemotherapeutic-resistant mammary adenocarcinoma (SKBr-3). Related investigations evaluated the potential for gemcitabine-(C₄-amide)-[anti-HER2/neu] in dual combination with griseofulvin to evoke increased levels of anti-neoplastic cytotoxicity compared to gemcitabine-(C₄-amide)-[anti-HER2/neu].

Results

Covalent gemcitabine-(C₄-amide)-[anti-HER2/neu] immunochemotherapeutic and griseofulvin exerted anti-neoplastic cytotoxicity against chemotherapeutic-resistant mammary adenocarcinoma (SKBr-3). Covalent gemcitabine-(C₄-amide)-[anti-HER2/neu] immunochemotherapeutic or gemcitabine in dual combination with griseofulvin created increased levels of anti-neoplastic cytotoxicity that were greater than was attainable with gemcitabine-(C₄-amide)-[anti-HER2/neu] or gemcitabine alone.

Conclusion

Gemcitabine-(C₄-amide)-[anti-HER2/neu] in dual combination with griseofulvin can produce enhanced levels of anti-neoplastic cytotoxicity and potentially provide a basis for treatment regimens with a wider margin-of-safety. Such benefits would be possible through the collective properties of; [i] selective “targeted” gemcitabine delivery; [ii] relatively lower toxicity of griseofulvin compared to many if not most conventional chemotherapeutics; [iii] reduced total dosage requirements faciliated by additive or synergistic anti-cancer properties; and [iv] differences in sequelae for gemcitabine-(C₄-amide)-[anti-HER2/neu] compared to griseofulvin functioning as a tubulin/microtubule inhibitor.

Effect of hydrophilic diluents on the release profile of griseofulvin from tablet formulations

Studies have shown that when compressing drugs with low aqueous solubility, the solubility of diluents selected is very crucial as it influences the disintegration, dissolution and bioavailability of such drugs. Based on these reports, the present study was undertaken to investigate the effect of some commonly used hydrophilic tablet diluents (lactose, sucrose, mannitol and dextrose) on the in vitro release properties of griseofulvin from compressed tablets. Griseofulvin granules and tablets were prepared using the wet granulation method. Tablet properties evaluated as a function of the diluents used include, hardness, friability, dissolution profile and dissolution efficiency at 60 min. Results obtained indicated variability in griseofulvin release in the presence of the diluents. The relative enhanced dissolution effects of the four hydrophilic diluents is in the order of dextrose>sucrose>lactose>mannitol. All the griseofulvin tablet batches produced exhibited a better drug release (in terms of rate and extent of release) than a commercially available tablet sample of griseofulvin (Fulcin(®)). The results of the dissolution efficiency (DE60min) are 91.7, 83.5, 48.7, 35.3 and 15.6% for dextrose, sucrose, lactose, mannitol and fulcin(®), respectively. The overall results indicated that dextrose or sucrose can be utilised to improve the in vitro release profile and hence in vivo bioavailability of griseofulvin from compressed tablets.