Ketoprofen

Ketoprofen mesoporous silica nanoparticles SBA-15 hard gelatin capsules: preparation and in vitro/in vivo characterization

SBA-15 is used to enhance the bioavailability of poorly soluble ketoprofen (KP) through stabilization of its amorphous state. Additionally, the current work provides a complete in vitro and in vivo study on preformulated KP-SBA-15 sample and formulated KP-SBA-15 in hard gelatin capsule. Loading of KP was done by a novel method called immersion-rotavapor method. KP was quantified by extraction and thermal gravimetric analysis (TGA). Characterization of the loaded SBA-15 sample was done by high resolution transmission electron microscopy (HRTEM), small angle X-ray diffraction (SAXRD), nitrogen adsorption/desorption isotherms, differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) spectroscopy and dissolution profiles. The loaded sample was formulated in hard gelatin capsule. The anti-inflammatory and analgesic studies were carried out on 24 adult male albino rats. TGA and extraction results showed 54.4 wt% of drug incorporated. Characterization of KP-SBA-15 sample confirmed the successful encapsulation of KP into the carrier pores in a molecular amorphous state. Additionally, loading of KP did not affect the mesoporous internal structure. During the first 5 min, the dissolution study showed very high release rates; nearly 50% of KP was released. These results were reflected on the in vivo study resulting in 82% inhibition in edema after 1 h and maximum analgesia after 30 min from the administration of the formulated sample. SBA-15 mesoporous silica nanoparticle proved to be a very promising drug delivery carrier that can be used as a facile way to enhance the bioavailability of poorly soluble drugs.

Design and characterization of sustained release ketoprofen entrapped carnauba wax microparticles

CONTEXT

Ketoprofen is a non-steroid anti-inflammatory drug (NSAID) used in the treatment of rheumatic diseases and in mild to moderate pain. Ketoprofen has a short biological half-life and the commercially available conventional release formulations require dosages to be administered at least 2-3 times a day. Due to these characteristics, ketoprofen is a good candidate for the preparation of controlled release formulations.

OBJECTIVES

In this work, a multiparticulate-sustained release dosage form containing ketoprofen in a carnauba wax matrix was developed.

METHODS

Particles were prepared by an emulsion congealing technique. System variables were optimized using fractional factorial and response surface experimental design. Characterization of the particles included size and morphology, flow rate, drug loading and in vitro drug release.

RESULTS

Spherical particles were obtained with high drug load and sustained drug release profile. The optimized particles had an average diameter of approximately 200 µm, 50% (w/w) drug load, good flow properties and prolonged ketoprofen release for more than 24 h.

CONCLUSIONS

Carnauba wax microspheres prepared in this work represent a new multiparticulate-sustained release system for the NSAID ketoprofen, exhibiting good potential for application in further pharmaceutical processes.

Dissolution rate enhancement by adsorption of poorly soluble drugs on hydrophilic silica aerogels

The aim of this work is to evaluate the feasibility of hydrophilic silica aerogels as drug carriers and to investigate the influence of the aerogels properties on the release rate of poorly water-soluble drugs. Hydrophilic silica aerogels of different densities were loaded with two model drugs, ketoprofen and griseofulvin, by adsorption from their solution in supercritical CO2. It is demonstrated that up to 30 wt% of ketoprofen and 5.4 wt% of griseofulvin can be deposited on hydrophilic aerogels through physical adsorption. The obtained drug-aerogel formulations were characterized by IR- and UV-spectroscopy, X-ray diffraction and scanning electron microscopy. Release kinetics of both drugs were studied in vitro. The release rate of ketoprofen from the drug-aerogel formulation is much faster than that of the corresponding crystalline drugs. The release rate of ketoprofen increases in 500% and that of griseofulvin in 450%, respectively. The reasons for the release enhancement are the enlarged specific surface area of drugs by adsorption on aerogels compared to their crystalline form and the immediate collapse of aerogel network in aqueous media. The dissolution rate of poorly water soluble drugs can be significantly enhanced by adsorption on highly porous hydrophilic silica aerogels.

A new approach for preparing a controlled release ketoprofen tablets by using beeswax

Solid lipid ketoprofen micropellets (SLKM) at different drug/beeswax ratios [(1:1) and (1:2)] were prepared by emulsion congealing technique and then compressed into tablets. Ketoprofen in solid state was incorporated into the melted beeswax at 90 degrees C and the mixture was emulsified in the hot aqueous Tween 80 solution by stirring at a constant rate. The SLKM were obtained by cooling the coarse emulsion down to room temperature and filtering. Drug entrapment efficiency and particle size analysis by laser diffractometry (LD) were determined, and existence of a drug-lipid interaction was investigated by differential scanning calorimetry (DSC) on the SLKM, before being compressed into the tablets by direct compression method. Finally, in vitro release studies were performed and the release kinetics of the waxy tablets were calculated. A commercial ketoprofen retard tablet (reference: Profenid Retard 200 mg) was also examined to compare the release properties. While the data obtained from DSC were indicating absence of drug-lipid interaction in the SLKM, it was determined that 28.62% (+/-2.08), 38.60% (+/-1.91) and 47.00% (+/-1.82) of ketoprofen was released from the tablets containing (1:2) and (1:1) SLKM and Profenid Retard 200 mg in pH 7.4 phosphate buffer solution after 8 h, respectively.

Immediate Drug Release from Solid Oral Dosage Forms

Fast drug release from solid dosage forms requires a very fast contact of the vast majority of the drug particles with the solvent; this, however, is particularly delayed in tablets and granulations. Starch and cellulose substances favor the matrix disintegration during the starting phase and the generation of the effective dissolution surface of the drug substance, thereby. To investigate the very complex interrelation between the functionality of commonly used excipients and the structural effects of the production processes, wettability, porosity, water uptake, and drug release rates of several ketoprofen-excipient preparations (powder blends, granulations, tablets) were measured. Significant linear correlation between these parameters, however, was not achieved; only qualitative tendencies of the effects could be detected. In consequence, a general mathematical model describing the mechanistic steps of drug dissolution from solid dosage forms in a fully correct way was not realized. However, the time-dependent change of the effective dissolution surface follows stochastic models: a new dissolution equation is based on the differential Noyes-Whitney equation combined with a distribution function, e.g. the lognormal distribution, and numerically solved with the software system EASY-FIT by fitting to the observations. This new model coincides with the data to a considerably higher degree of accuracy than the Weibull function alone, particularly during the starting, matrix disintegration, and end phases. In combination with a procedure continuously quantifying the dissolved drug, this mathematical model is suitable for the characterization and optimization of immediate drug release by the choice and modification of excipients and unit operations. The interdependence of some characteristic effects of excipients and production methods is discussed.

Comparison of effects of different ointment bases on the penetration of ketoprofen through heat-separated human epidermis and artificial lipid barriers

In vitro tests were performed to understand the effects of topical vehicles on the permeability of ketoprofen through artificial lipid barriers and heat-separated human epidermis consisting of stratum corneum and viable epidermis. Ketoprofen was selected as the model penetrant. Human epidermis and artificial membranes made from several mixtures of free fatty acids, cholesterol, cholesteryl ester, ceramides, and triglycerides were used as permeation matrices in untreated conditions and after pretreatment with petrolatum, wool alcohols ointment, or triglycerides. Apparent permeability and diffusion coefficients as well as the solubility of the drug in the artificial lipid matrices were ascertained. The solubilities of drugs and vehicle components that depend on the composition of the lipid matrix predominantly control the permeability of the barrier. Ceramides and cholesterol reduce the permeability and solubility, whereas triglycerides have the opposite effect. The vehicle effects in artificial membranes correspond to those in epidermis observed with samples pretreated with the aforementioned bases. The logarithms of the permeabilities of untreated and pretreated lipid mixtures 3, 4, and 5 are very well correlated with those of the permeabilities of heat-separated epidermis (r > = 0.9868). The artificial mixture containing all five lipids mentioned gives the best approximation to human epidermis. This result indicates comparable vehicle effects although the composition of the artificial mixture was adapted only in a simplified manner to the horny layer lipid phase. This lipid matrix or similar mixtures, therefore, are convenient tools for investigation into the effects of dermatological vehicles.

Bioavailability of a new ketoprofen formulation for once-daily oral administration

A new sustained-release formulation (sustained release Ibifen) that gradually releases ketoprofen within 24 h and ensures therapeutic plasma concentration for the entire period has been developed. It consists of tableted pH-dependent barrier film-coated ketoprofen granules and was administered at a single dose of 200 mg to 12 volunteers. Ketoprofen plasma profiles were compared with: (1) administration of Orudis retard 200 capsule (200 mg); (2) two 12-h doses of prompt release Ibifen capsules (100 mg). In vitro dissolution kinetics and ketoprofen plasma levels were measured by HPLC. Sustained release Ibifen dissolution rate was constant for 10 h, whereas Orudis retard 200 dissolution profile presented one higher slope (0-6 h) and a lower one (6-12 h). Both formulations showed a delayed kinetics with respect to prompt release Ibifen. After sustained release Ibifen administration, ketoprofen plasma peak, reached within 2 h, remained practically constant for at least 12 h (average 4 microg/ml), which is higher than therapeutic levels. Differently, Orudis retard 200 produced a delayed, higher C(max) (5.91+/-0.66 vs. 4.51+/-0.65 microg/ml; P<0.01) and disappeared more quickly. In conclusion, sustained release Ibifen can ensure therapeutic ketoprofen plasma levels for the entire 24 h period, avoiding plasma concentration spikes, with bioavailability similar to other ketoprofen preparations.

Effects of grinding with microcrystalline cellulose and cyclodextrins on the ketoprofen physicochemical properties

Ground mixtures of ketoprofen (KETO) with native crystalline beta-cyclodextrin, amorphous statistically substituted methyl-beta-cyclodextrin, and microcrystalline cellulose were investigated for both solid phase characterization (differential scanning calorimetry (DSC) powder X-ray diffractometry, and infrared (IR) spectrometry) and dissolution properties (dispersed amount and rotating disk methods) to evaluate the role of the carrier on the performance of the final product. The effects of different grinding conditions, partial sample dehydration, and 1 year storage at room temperature were also investigated. The results pointed out the importance of the carrier nature on the efficiency of the cogrinding process. Both cyclodextrins were much more effective than was microcrystalline cellulose, even though no true inclusion complex formation occurred by mechanochemical activation. The best results were obtained from ground mixtures with methyl-beta-cyclodextrin, which showed the best amorphizing and solubilizing power toward the drug and permitted an increase of approximately 100 times its intrinsic dissolution rate constant, in comparison with the approximate 10 times increase obtained from ground mixtures with beta-cyclodextrin.

Inclusion of ketoprofen with skimmed milk by freeze-drying

Ketoprofen is a non-steroidal anti-inflammatory drug which is not soluble in water and creates gastrointestinal problems. In order to improve the solubility of the drug in water and enhance its dissolution rate, physical mixture (PM) and inclusion (IC) of ketoprofen with skimmed milk (SM) were prepared and investigated. Enhancement of solubility of ketoprofen was obtained by preparing its IC with SM which can be used because of its amino acid and surface active agents content and can also be used for treatment of gastric disturbance. Lyophilization technique was used to prepare the IC. Results obtained showed that the solubility of IC of ketoprofen with SM was almost four times greater than the solubility of the plain drug. Data from the dissolution rate determination have also indicated that IC of ketoprofen with SM significantly improved the dissolution rate of the drug compared with PM and the plain form. Differential scanning calorimetry (DSC), X-ray powder diffraction and scanning electron microscopic (SEM) analysis revealed the formation of IC of ketoprofen with SM.

Effects of ultrasound-assisted compaction on Ketoprofen/Eudragit S100 mixtures

Ketoprofen alone and in binary mixtures with Eudragit S100 was compacted by an ultrasound-assisted (US) tableting machine at an energy ranging from 50 to 400 J. The final material was analysed by TLC and HPLC: no decomposition product of the active agent was found. IR spectra and HSM revealed the absence of any interaction between the two components. Thermal analysis (DSC) evidenced that ketoprofen inside the mixtures was transformed into an amorphous state, documented by the decreasing of the DeltaHfus as the Eudragit/ketoprofen ratio increases and as US energy increases. While pure ketoprofen recovers its crystalline state quickly after the US treatment, the presence of Eudragit was found to slow down or possibly to prevent the regeneration of the crystallinity.

Identification of a benzhydrolic metabolite of ketoprofen in horses by gas chromatography-mass spectrometry and high-performance liquid chromatography

A benzhydrolic metabolite of ketoprofen, formed by reduction of the keto group of the drug, has been identified by gas chromatography-mass spectrometry in equine plasma and urine. After partial synthesis, its structure has been confirmed by UV, IR and 1H NMR spectroscopy. The kinetics of ketoprofen and this metabolite have been monitored in plasma by high-performance liquid chromatography. The two products were quantified in plasma up to 4 and 3 h, respectively, and were detected in urine up to 72 and 24 h, respectively, after a single intravenous administration to horses at the dose of 2.2 mg/kg. Simultaneous detection of both compounds increases the reliability of antidoping control analysis.