Caffeine Release Research Articles

Hydrophilic drug release from electrospun membranes made out of thermo and pH-sensitive polymers

Electrospun fibers of the thermo-and pH sensitive poly(N-vinylcaprolactam-co-acrylic acid) (Poly(NVCL-co-AA) loaded with 10% and 30 wt% caffeine (Caf) were obtained by electrospinning and evaluated as potential drug delivery systems. Caffeine was used as a hydrophilic drug model, and poly(NVCL-co-AA) containing either 20 or 30 mol% AA was used as a carrier. The fibers morphology, as well as, their interaction with caffeine, were studied using different analytical techniques. The cytotoxicity of the different obtained fibers was evaluated by cell viability assays using 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and mouse embryonic fibroblasts cell line (MEF cells). Caffeine release was studied at temperatures of 25 °C and 42 °C and pH of 1.2 and 7.4. Beadless copolymer fibers with diameters ranging from 1 μm to 2 μm were obtained. The addition of caffeine, which was in crystalline form after being encapsulated in the fibers, resulted in an increase of fiber diameter. The obtained membranes were found to be not cytotoxic. The entrapment of caffeine was greater for the copolymer containing 30 mol% AA due to a greater affinity of AA to caffeine. At a pH of 1.2 and at both temperatures of 25 °C and 42 °C, as well as, at a pH of 7.4 and a temperature of 42 °C, a Fickian diffusion mechanism for all copolymer fiber mats was observed. At a pH of 7.4 and 25 °C the release profile showed a high rate and followed a zero-order model, due to the fast dissolution of caffeine in water. These results indicated that thermo-and pH-sensitive poly(NVCL-co-AA) are promising candidates for controlled release of hydrophilic drugs.

Effect of neutralization degree of methacrylic acid on hydrogel swelling and drug release

Drug delivery system is an amazing tool which is widely used for drug protection and its controlled release in order to enhance drug bioavailability, reduce side effects and therefore to improve overall therapy. Hydrogels have been attracted great attention as drug carriers due to their great physicochemical properties, similarity to the living tissues and biocompatibility. One group of pH sensitive hydrogels are based on poly(methacrylic acid) (PMAA). These non-toxic hydrogels are used as drug delivery system because they swell as a response to the change in pH of external environment and drug is being released during the process. In present study, in order to improve the control of drug release rate, caffeine was encapsulated in liposomes which were further embedded into PMC hydrogel (PMCL). It was investigated how the change in neutralization degree of methacrylic acid affect the swelling degree of PMCL hydrogels and caffeine release in two environments at 37 °C for 24 h: 0.1 M hydrochloride acid (pH 1) and phosphate buffer with pH value of 6.8 (pH 6.8), as a simulation of pH environment in human stomach and intestines, respectively. Obtained results show that PMCL hydrogels have great potential for controlled release of poorly water-soluble drugs in human intestines.

The effect of trisodium phosphate crosslinking on the diffusion kinetics of caffeine from chitosan networks

This work examines the relationship between microstructural properties of hot-moulded chitosan networks, crosslinked with trisodium phosphate, and diffusive behaviour from these networks. Analysis through infrared spectroscopy (FTIR) confirmed successful crosslinking of the polymer chains and bioactive entrapment, while X-ray diffraction (WAXD) and dynamic oscillation in-shear elucidated the higher order structural properties of each matrix, as they transitioned from solutions to amorphous gels to semi-crystalline matrices. The picture of molecular motion observed in these systems and consequent application of the Flory-Rehner theory further indicated that different extents of chitosan crosslinking yielded a distinct water infusion functionality seen in the levels of swelling. Diffusion of caffeine from these delivery vehicles showed that network structural properties (governed by crosslinker concentration) had a significant effect on the release kinetics of the entrapped bioactive. The relationship between network mesh characteristics and diffusion properties were further confirmed by correlating caffeine release rates and molecular pore size.

The relative importance of internal and external physical resistances to mass transfer for caffeine release from apple pectin tablets

The relative importance of the physical resistances to mass transfer have been explored by using halved 13 mm diameter apple-pectin tablets containing caffeine, in different external stirring environments within a beaker containing simulated gastric fluid. The effects of different external (outside of the tablets) mass-transfer resistances to the tablets created through two different stirrer types and stirrer speeds, and different internal (inside of the tablets) mass-transfer resistances created through different tablet concentrations and thicknesses, have been studied. These studies enable internal diffusion coefficients of caffeine through the apple pectin matrix to be estimated, as well as estimating the external mass-transfer coefficients from benzoic acid dissolution, which are in the range of 6.5 × 10-6 m/s – 2.4 × 10-5 m/s for the 0.6 mm thick tablets and 4.0 × 10-6 m/s – 1.6 × 10-5 m/s for the 7 mm thick tablets. The diffusion coefficients for different caffeine concentrations in the apple pectin half-tablets have also been calculated in this study. The diffusivity of caffeine in the 7 mm half-tablets with 1% caffeine through 99% pectin was around (1.8 ± 0.5) × 10-10 m2/s. This study points towards the development of multifilm mass-transfer theory for food digestion to create a more fundamentally based understanding of in-vitro digestion systems as an addition to the use of realistic in-vitro food digestion apparatus and give a better correlation between in-vitro and in-vivo digestion tests.

The Effect of Capsule-in-Capsule Combinations on In Vivo Disintegration in Human Volunteers: A Combined Imaging and Salivary Tracer Study.

Controlling the time point and site of the release of active ingredients within the gastrointestinal tract after administration of oral delivery systems is still a challenge. In this study, the effect of the combination of small capsules (size 3) and large capsules (size 00) on the disintegration site and time was investigated using magnetic resonance imaging (MRI) in combination with a salivary tracer technique. As capsule shells, Vcaps® HPMC capsules, Vcaps® Plus HPMC capsules, gelatin and DRcaps® designed release capsules were used. The three HPMC-based capsules (Vcaps®, Vcaps® Plus and DRcaps® capsules) were tested as single capsules; furthermore, seven DUOCAP® capsule-in-capsule combinations were tested in a 10-way crossover open-label study in six healthy volunteers. The capsules contained iron oxide and hibiscus tea powder as tracers for visualization in MRI, and two different caffeine species (natural caffeine and 13C3) to follow caffeine release and absorption as measured by salivary levels. Results showed that the timing and location of disintegration in the gastrointestinal tract can be measured and differed when using different combinations of capsule shells. Increased variability among the six subjects was observed in most of the capsule combinations. The lowest variability in gastrointestinal localization of disintegration was observed for the DUOCAP® capsule-in-capsule configuration using a DRcaps® designed release capsule within a DRcaps® designed release outer capsule. In this combination, the inner DRcaps® designed release capsule always opened reliably after reaching the ileum. Thus, this combination enables targeted delivery to the distal small intestine. Among the single capsules tested, Vcaps® Plus HPMC capsules showed the fastest and most consistent disintegration.

A novel bedtime pulsatile-release caffeine formula ameliorates sleep inertia symptoms immediately upon awakening

Sleep inertia is a disabling state of grogginess and impaired vigilance immediately upon awakening. The adenosine receptor antagonist, caffeine, is widely used to reduce sleep inertia symptoms, yet the initial, most severe impairments are hardly alleviated by post-awakening caffeine intake. To ameliorate this disabling state more potently, we developed an innovative, delayed, pulsatile-release caffeine formulation targeting an efficacious dose briefly before planned awakening. We comprehensively tested this formulation in two separate studies. First, we established the in vivo caffeine release profile in 10 young men. Subsequently, we investigated in placebo-controlled, double-blind, cross-over fashion the formulation’s ability to improve sleep inertia in 22 sleep-restricted volunteers. Following oral administration of 160 mg caffeine at 22:30, we kept volunteers awake until 03:00, to increase sleep inertia symptoms upon scheduled awakening at 07:00. Immediately upon awakening, we quantified subjective state, psychomotor vigilance, cognitive performance, and followed the evolution of the cortisol awakening response. We also recorded standard polysomnography during nocturnal sleep and a 1-h nap opportunity at 08:00. Compared to placebo, the engineered caffeine formula accelerated the reaction time on the psychomotor vigilance task, increased positive and reduced negative affect scores, improved sleep inertia ratings, prolonged the cortisol awakening response, and delayed nap sleep latency one hour after scheduled awakening. Based on these findings, we conclude that this novel, pulsatile-release caffeine formulation facilitates the sleep-to-wake transition in sleep-restricted healthy adults. We propose that individuals suffering from disabling sleep inertia may benefit from this innovative approach.Trials registration: NCT04975360.

Supercritical CO2 impregnation of caffeine in biopolymer films to produce anti-cellulite devices

The present work focuses on the production of topical anti-cellulite devices through a supercritical one-step process consisting of the polymer foaming and impregnation of caffeine into PLA/PBAT/CaCO3 films to obtain a biocompatible and biodegradable patch. Field Emission Scanning Electron Microscopy analysis revealed that porosities were formed in the polymeric support when in contact with the supercritical CO2. Atomic force microscopy revealed the presence of caffeine on the polymer surface in the form of needles. The impregnation kinetics determined at 17.0 MPa showed an increase in caffeine loadings with the contact time (up to 16.5% and 23.0% wcaffeine/wfilm at 40 °C and 35 °C, respectively), corresponding to higher caffeine loadings than the ones contained in commercial products (about 3%). The release of caffeine was simulated by UV–vis spectrophotometry: pure caffeine dissolved instantly in the dissolution medium, whereas its release was prolonged up to 2 days when it was impregnated within the PLA/PBAT/CaCO3 film.

Effect of disintegrants and tablet infill on release behaviour of 3D printed tablets

The polymer hypromellose (HPMC) is widely used for 3D printing of pharmaceutical dosage forms. This paper deals with the study of acceleration of drug release from 3D printed HPMC tablets. Polyvinylpyrrolidone (PVP) was added and the infill of the tablets was also varied. Both, lower infill and addition of PVP, can accelerate the drug release of caffeine from 3D printed HPMC tablets.

Comparison of protection and release behavior of different capsule polymer combinations based on L. acidophilus survivability and function and caffeine release

Oral administration of active pharmaceutical ingredients, nutraceuticals, enzymes or probiotics requires an appropriate delivery system for optimal bioactivity and absorption. The harsh conditions during the gastrointestinal transit can degrade the administered products, hampering their efficacy. Enteric or delayed-release pharmaceutical formulations may help overcome these issues. In a Simulator of Human Intestinal Microbial Ecosystem model (SHIME) and using caffeine as a marker for release kinetics and L. acidophilus survivability as an indicator for protection, we compared the performance of ten capsule configurations, single or DUOCAP® combinations. The function of L. acidophilus and its impact on the gut microbiota was further tested in three selected capsule types, combinations of DRcaps® capsule in DRcaps® capsule (DR-in-DR) and DRcaps® capsule in Vcaps® capsule (DR-in-VC) and single Vcaps® Plus capsule under colonic conditions. We found that under stomach and small intestine conditions, DR-in-DR and DR-in-VC led to the best performance both under fed and fasted conditions based on the slow caffeine release and the highest L. acidophilus survivability. The Vcaps® Plus capsule however, led to the quickest caffeine and probiotic release. When DR-in-DR, DR-in-VC and single Vcaps® Plus capsules were tested through the whole gastrointestinal tract, including under colonic conditions, caffeine release was found to be slower in capsules containing DRcaps® capsules compared to the single Vcaps® capsules. In addition, colonic survival of L. acidophilus was significantly increased under fasted conditions in DR-in-DR or DR-in-VC formulation compared to Vcaps® Plus capsule. To assess the impact of these formulations on the microbial function, acetate, butyrate and propionate as well as ammonia were measured. L. acidophilus released from DR-in-DR or DR-in-VC induced a significant increase in butyrate and a decrease in ammonia, suggesting a proliferation of butyrate-producing bacteria and reduction in ammonia-producing bacteria. These data suggest that L. acidophilus included in DR-in-DR or DR-in-VC reaching the colon is viable and functional, potentially contributing to changes in colonic microbiota composition and diversity.

The Impact of Titanium Dioxide Type Combined with Coffee Oil Obtained from Coffee Industry Waste on Sunscreen Product Performance

(1) Background: Titanium dioxide (TiO2) consists of three polymorphs, including anatase, rutile and brookite. This work aimed to elucidate the influence of rutile and anatase forms in the performance of sunscreens formulated with green coffee oil (GCO) from coffee beans discarded in the agri-food industry. (2) Methods: TiO2 particles were characterized in terms of size and wettability. The sunscreens formulated with GCO were characterized regarding the droplet size, rheology, texture profile analysis (TPA), in vitro Sun Protection Factor and Water Resistance Retention. Topical delivery and permeation studies were performed to confirm caffeine release and skin penetration. (3) Results: Particle size distributions of rutile and anatase TiO2 particles were similar, however, smaller droplets as well as decreased viscosity and increased thixotropy were obtained for anatase TiO2 and GCO formulation compared to rutile form formulations. Notwithstanding, all formulations exhibited linear viscoelastic behavior. Regarding the TPA, a wide range of mechanical properties improved mainly by GCO rather than TiO2 form has been demonstrated. The influence of TiO2 form on UV protection was better evidenced in absence of GCO. The sunscreen formulations containing GCO presented a favorable topical delivery as confirmed by caffeine release and permeation. (4) Conclusions: Both TiO2 forms combined with GCO provided suitable properties including an effective ultraviolet (UV)-light protection.

Developing and evaluation of orodispersible tablets containing caffeine

Starting from the premise that a reduced number of active pharmaceutical ingredients (APIs) are used to treat hypotension, the aim of this study consisted of developing new formulations of caffeine-orodispersible tablets (CAFODTs). The formulation variables were the type of disintegrant and its concentration. The CAF-ODTs were prepared by direct compression, (CAF1, CAF2 and, CAF3) each of them containing 100 mg of CAF / tablet. The proposed formulations were analyzed from a pharmacotechnical point of view. For the formulations developed the tablets’ physical appearance, resistance to crushing, friability, disintegration behaviour, and the in vitro caffeine release were evaluated. White tablets, with a resistance to crushing decreasing in the following order CAF1 > CAF2 > CAF3 were obtained. The friability test showed that all the formulations are respecting the in-force European Pharmacopoeia (Ph. Eur. 10) requirements with values less than 1 %. The disintegration time for all three formulations was less than 180 seconds, the smallest time being registered in the case of CAF2 formulation, where Sodium Starch Glycolate (SSG) was used as a disintegrant (24-30 s, as a result of the different methods used. Through the in vitro releasing study, it was observed that over 99.9 % caffeine was released from all three analyzed formulations. By investigating the amount of caffeine released after 1 minute, it can be noticed that the largest amount released was recorded in CAF2 formulations, where SSG was used as a disintegrant. Compared to CAF2, the amount of CAF released was reduced to half, after the first five minutes for CAF1 formulation, where sodium croscarmellose was used, and ten times lower in the case of CAF3 where no disintegrant was used. Based on the results obtained we can conclude that all three formulations are respecting the pharmacotechnical in-force officinal requirements. The presence of SSG in the CAF2 formulation led to obtaining tablets with a reduced disintegration time in comparison to the other two formulations proposed in this study.

Skin barrier modulation by Hibiscus rosa-sinensis L. mucilage for transdermal drug delivery

Transdermal drug delivery system provides continuous controlled delivery of active ingredients through the human skin and into the bloodstream. Poor penetration of most drugs into the skin has led to numerous studies being conducted to increase their permeability. The present study investigated the ability of Hibiscus rosa-sinensis L. (HRS) leaves mucilage, a novel source of polysaccharide in modifying skin barrier for transdermal drug delivery. Dried-powdered mucilage was extracted from the leaves and was transformed into HRS gels using three concentrations of HRS mucilage, namely 1 (CL1), 1.5 (CL1.5), and 2 (CL2) % (w/w) while caffeine was employed as a model drug. The in vitro drug release and permeation profiles of caffeine were examined using vertical diffusion cells. Physicochemical properties of HRS mucilage were characterized, and the morphological and structural features of skin samples were evaluated using scanning electron microscopy, attenuated total reflectance Fourier transform infrared spectroscopy, as well as differential scanning calorimetry. The HRS gel of CL2 demonstrated a significantly highest drug permeation when compared to caffeine solution, CL1, and CL1.5 (ANOVA: p < 0.05). HRS mucilage in the form of a gel altered the barrier and permeability of skin by perturbing the lipid and protein structures, acting on the helical keratin filaments as well as through the O–H and/or N–H interactions. These were then reduced the diffusional resistance for drug transport and increased the drug permeation. The optimal concentration of HRS mucilage at 2% (w/w) was deemed useful in facilitating the transdermal delivery of caffeine.

The impact of P/Ca molar ratio on physicochemical and release properties of calcium polyphosphate coacervates

This paper reports on the synthesis and characterization of gel-like calcium polyphosphate coacervates (Ca–PPCs) with three different [P]:[Ca] ratios as new matrixes for drug release. Caffeine and chlorhexidine were used as model drugs, showing encapsulation efficiency of up to 95.4% and 70.4%, respectively. Based on the correlation coefficient (r2) values, different in vitro release behaviors were determined. While the caffeine release followed the Weibull model, the chlorhexidine release was best described by the Korsmeyer-Peppas model. The caffeine-loaded coacervate sample with the highest Ca2+ concentration (CAFPCa0.5) showed the highest incorporation and a total drug release within 720 min. The Ca-PPC-drug interactions were evaluated by infrared and Raman spectroscopies. The Ca2+ concentration, drug molecule size and intermolecular drug/matrix interactions determined the incorporation and release of drugs in the polyphosphate coacervates. High calcium concentration led to a Ca-PPC with small and tight “cage-like” structure that better incorporated caffeine molecules because of their 4.3 times smaller size compared to chlorhexidine. In addition, caffeine interacted through van der Waals' forces with polyphosphate and its release from the coacervates was most likely to occur in relation to chlorhexidine, which interacted with the coacervates through hydrogen bonding. Thus, the calcium polyphosphate coacervates loaded with the proposed drugs can be competitive and promising as drug delivery systems.

Encapsulation of caffeine into starch matrices: Bitterness evaluation and suppression mechanism

In this study, caffeine (CA) was encapsulated into food-grade starch matrices, including swelled starch (SS), porous starch (PS), and V-type starch (VS). The bitterness of the microcapsules and suppression mechanisms were investigated using an electronic tongue, molecular dynamics (MD) simulation and the in vitro release kinetics of CA. All the CA-loaded microcapsules showed a lower bitterness intensity than the control. The MD results proved that the weak interactions between starch and CA resulted in a moderate CA release rate for SS-CA microcapsules. The PS-CA microcapsule presented the longest CA release, up to 40 min, whereas the VS-CA microcapsule completely released CA in 9 min. The CA release rate was found to be related to the microcapsule structure and rehydration properties. A low CA bitterness intensity could be attributed to a delay in the CA release rate and resistance to erosion of the microcapsules. The results of this work are valuable for improving starch-based microcapsules (oral-targeted drug-delivery systems) by suppressing the bitterness of alkaloid compounds.

Comparative isoconversional thermal analysis of Artemisia vulgaris hydrogel and its acetates; a potential matrix for sustained drug delivery

Artemisia vulgaris hydrogel (AVH) was acetylated (AAVH) and characterized by FTIR, CP/MAS 13C-NMR spectroscopic techniques and thermogravimetric analysis. Flynn–Waal–Ozawa model was used to investigate thermal degradation kinetics. Energy of activation (Ea) values of first and major thermal degradation steps were found to be 128.14 and 116.85 kJmol−1 for AVH and AAVH, respectively. Thermodynamic triplet, order of degradation reaction, integral procedural decomposition temperature (IPDT) and comprehensive index of intrinsic thermal stability (ITS) were also taken into account. In vitro caffeine release from AVH-based matrix tablets indicates potential of AVH for the development of oral delivery systems for sustained drug release.

Preparation and evaluation of caffeine bioadhesive emulgels for cosmetic applications based on formulation design using QbD tools.

The aim of the present study was to evaluate the influence of the incorporation of caffeine as a model active ingredient on the quality attributes of a bioadhesive emulgel formulation previously optimized by Quality by Design (QbD) tools. Emulgels are emerging topical drug delivery systems for cosmetic or pharmaceutical uses, which combine the advantages of both emulsions and gels. In this work, the observed and predicted values for spreadability, phase separation by centrifugation and detachment forces performed by texturometer were compared with those of the control and active-containing emulgel formulations. In addition, rheological properties, release of caffeine and comparative in vitro/ex vivo bioadhesion properties were evaluated using human skin. The flow curves of emulgel formulations showed the typical pseudoplastic and no thixotropic flow with yield stress. The incorporation of active ingredient did not produce significant changes. All emulgels were uniformly spread and no significant differences in spreadability values between control and caffeine containing formulations and neither respect to those predicted values from experimental design optimization were found. Emulgel formulations showed appropriate detachment forces values and no significant differences between caffeine loading and control emulgel formulations were observed. Caffeine was successfully vehiculized in this optimized bioadhesive emulgel formulation, which showed high robustness regarding the process variability. There were no significant changes in the critical quality attributes after the incorporation of the active ingredient and a promising stability was observed for at least one year. Results suggested that the optimized emulgel is an interesting topical biodhesive delivery system for cosmetic applications, including agents for skin conditioning, not present in gels formulations.

Mechanisms of water permeation and diffusive API release from stearyl alcohol and glyceryl behenate modified release matrices.

This work aims to develop complimentary analytical tools for lipid formulation selection that offer insights into the mechanisms of in-vitro drug release for solid lipid modified release excipients. Such tools are envisioned to aide and expedite the time consuming process of formulation selection and development. Two pharmaceutically relevant solid lipid excipients are investigated, stearyl alcohol and glyceryl behenate, which are generally known to exhibit faster and slower relative release rates, respectively. Nuclear magnetic resonance spectroscopy and diffusometry are used, along with water uptake and dissolution experiments to help distinguish between two proposed in-vitro release mechanisms for crystalline caffeine from these matrices: 1) rate limiting movement of the wetting front through the particle, and 2) rate limiting diffusive release of the active from the wetted particle. Findings based on water permeation rates, API diffusion coefficients and kinetic modeling suggest that the rate limiting steps for caffeine release from these matrices are different, with stearyl alcohol being co-rate limited by movement of the wetting front and diffusive release of API, whereas glyceryl behenate is more strictly limited by diffusive release of API from the wetted matrix. A Peclet-like number is proposed to describe the different regimes of rate limitation for drug release. NMR spectroscopy and diffusometry are demonstrated to be useful tools for elucidating mechanisms of API release from crystalline drug/lipid mixtures and have significant potential value as screening tools in MR formulation development.

Molecular characterisation of hot moulded alginate gels as a delivery vehicle for the release of entrapped caffeine

This work explores the process of alginate molecule crosslinking to form cohesive gels that were induced by the addition of calcium ions at various stoichiometric equivalents. Polysaccharide gels were used as a delivery vehicle for the study of transport phenomena of entrapped caffeine as the bioactive compound. Initial physicochemical characterisation through FTIR and WAXD of the alginate matrix showed successful inclusion of caffeine in the bulk system. Rheological analysis in the form of dynamic oscillation in-shear highlighted issues of developing network integrity and its eventual collapse with increasing levels of the crosslinker. Swelling in neutral solvent (water molecules) yielded information on the molecular features of the gel, as determined by the Flory-Rehner theoretical framework. Analysis of molecular transport with modified Fickian diffusion equations showed anomalous behaviour and a sustained release of caffeine. Overall, alteration in mesh size and diffusion parameters can be ascribed to the microstructural changes controlled by calcium crosslinking and the formation of junction zones in the alginate network.

A preformulation strategy for the selection of controlled-release components to simulate a subcutaneous implant

Many chronic diseases require repetitive injections as maintenance treatment. It is therefore important to investigate a possible alternative. A simulated subcutaneous implant prototype was fabricated as a polymer matrix covered by cylinder-shape tubing having a porous membrane. Sucrose, bovine serum albumin, and gelatin were selected as matrix excipients. Eight APIs with different physiochemical properties were used to investigate the releasing mechanism. Drug release was tested through an in vitro dissolution apparatus. Drug release of eight APIs followed zero-order kinetics with a minimum 12-hour duration. Release rates also showed linear correlations with the APIs’ solubilities under physiological pH. For releasing mechanism studies, different combinations of matrix and membrane were investigated in detail. A 144-hour continuous zero-order release of caffeine was achieved as the best controlled simulated prototype. The results showed that drug release of our simulated prototype was primarily achieved by drug diffusion rather than dissolution.

Acute and subacute oral toxicity assessment of dry encapsulated and non-encapsulated green coffee fruit extracts

The coffee fruit is a high source of bioactive compounds such as phenolic acids and methylxanthines, comprising chlorogenic acids and caffeine, respectively. Extract from this matrix may be used as supplement or active ingredient of functional foods, energy drinks, cosmetics or drugs. Safety of caffeine- and chlorogenic acid-rich encapsulated and non-encapsulated hydroethanolic extracts from green coffee fruit (GCFE) was assessed by acute and subacute toxicity tests. In the acute test, oral single dosage until 1000 mg/kg per body weight (bw) did not show any adverse effect on both female and male mice according to the Hippocratic screening and clinical parameters for a period of 14 days. While the oral median lethal dose of non-encapsulated GCFE was 5000 mg/kg bw/day, that of encapsulated GCFE was not detectable likely due to the delayed release of caffeine and other compounds from GCFE. Non-encapsulated GCFE displayed a stimulating effect at a dose of 1000 mg/kg bw/day after 30 min of oral administration, but not after 60 min. Daily consumption of encapsulated GCFE for 30 days showed no adverse effect in male rats even at the highest dose. Extrapolating this value of no-observed-adverse-effect level (1000 mg/kg bw/day) to human consumption, a human equivalent dose of 189 mg/kg bw/day or 11.34 g/day could be estimated for encapsulated GCFE considering a 60 kg adult body weight.