Determination of celecoxib in human plasma and breast milk by high-performance liquid chromatographic assay

Dimethyldioctadecylanimonium bentonite immobilized magnetic chitosan nanoparticles as an efficient adsorbent for vortex-assisted magnetic dispersive micro-solid-phase extraction of celecoxib from human breast milk, plasma and urine samples

A polymer/layered silicate composite based on dimethyldioctadecylanimonium bentonite/chitosan magnetic nanoparticles was synthesized and characterized by field emission transmission electron microscopy, X-ray diffraction and Fourier transform infrared spectrometry. The prepared nanocomposite was used to isolate and preconcentrate celecoxib from human breast milk, urine and plasma samples. In this method, dimethyldioctadecylanimonium bentonite increases the accessibility of binding sites and adsorption capacity by high microporosity and large surface area, that has been realized for the first time in a magnetic chitosan nanoparticle support. A fractional factorial design was utilized for screening the experimental parameters. The effective parameters were then optimized by Box-Behnken design. Under the optimized conditions, the developed method exhibited wide linear ranges of 5-500 μg L^-1 for plasma and urine and 10-500 μg L^-1 for breast milk samples with satisfactory recoveries in the range of 96.7-99.0%. Limit of detection and quantification of celecoxib were in the ranges 0.3-3.2 and 0.99-10.56, respectively. The enrichment factors were obtained in the ranges 64.5-66.0, while precisions were <3.7%.

Quantification of theophylline or paracetamol in milk matrices by high-performance liquid chromatography

A simple, accurate and sensitive high-performance liquid chromatography (HPLC) method was developed, validated and applied to the determination of either theophylline or paracetamol in milk-based samples. The method allowed drug quantification in fresh and powdered milk with a relatively short run time of analysis and it was also successfully applied to the quantification of the drugs in solid dosage forms intended for pediatric use. Moreover, the main significant advantages over other published works are the simplicity of the sample preparation, reduced assay time and sample loss. The method meets the International Conference on Harmonization guideline for analytical methods validation regarding specificity, linearity, accuracy, precision, specificity and robustness as required by health authorities and applied by industry while designing and marketing new drug products. The technique encompasses the separation of the analytes with a reverse phase C₁₈ column under isocratic conditions and UV detection at 272 nm and 243 nm, respectively, for theophylline and paracetamol. The lower limit of quantification for both drugs was determined as 0.2 µg/mL and the between-batch accuracy was approximately 99.7%. This HPLC method allows quantification of theophylline and paracetamol in milk matrices and it can be applied in the design, development and production of milk-based pediatric dosage forms.

Recent configurations and progressive uses of magnetic molecularly imprinted polymers for drug analysis

Since the introduction of the molecularly imprinting technology (MIT) in the 1970s, it becomes an emerging technology with the potential for wide-ranging applications in drug determination. With the rise of green chemistry, many researchers began to focus on the application and development of green materials which led to the breakthrough of molecularly imprinted polymers (MIPs) in the green chemistry. Because of the low concentration levels in the human matrices, almost adequate analytical methods should be used for quantification of drugs at the trace levels. In recent years there have been reported benefits of combining MIPs with additional features, e.g. magnetic properties, through the build-up of this type of material on magnetite particles. Magnetic molecularly imprinted polymer (MMIP) is a new material which is composed of magnetic material and non-magnetic polymer material and shares the characteristics of high adsorption capacity to template molecule, special selective recognition ability, and the magnetic adsorption property. These materials have been widely used in the different fields such as chemical, biological and medical science. This review describes the novel configurations and progressive applications of magnetic molecularly imprinted polymers to the drug analysis. Also, the advantages and drawbacks of each methodology, as well as the future expected trends, are evaluated.

Synthesis and application of molecularly imprinted nanoparticles combined ultrasonic assisted for highly selective solid phase extraction trace amount of celecoxib from human plasma samples using design expert (DXB) software

In this work molecular imprinted nanoparticles (MINPs) was synthesized and applied for ultrasonic assisted solid phase extraction of celecoxib (CEL) from human plasma sample following its combination by HPLC-UV. The MINPs were prepared in a non-covalent approach using methacrylic acid as monomer, CEL as template, ethylene glycol dimethacrylate as cross-linker, and 2,2-azobisisobutyronitrile (AIBN) as the initiator of polymerization. pH, volume of rinsing and eluent solvent and amount of sorbent influence on response were investigated using factorial experimental design, while optimum point was achieved and set as 250mg sorbent, pH 7.0, 1.5mL washing solvent and 2mL eluent by analysis of results according to design expert (DX) software. At above specified conditions, CEL in human plasma with complicated matrices with acceptable high recoveries (96%) and RSD% lower than 10% was quantified and estimated. The proposed MISPE-HPLC-UV method has linear responses among peak area and concentrations of CEL in the range of 0.2-2000μgL(-1), with regression coefficient of 0.98. The limit of detection (LOD) and quantification (LOQ) based on three and ten times of the noise of HPLC peaks correspond to blank solution were 0.08 and 0.18μgL(-1), respectively.

Effect of ultra-high pressure homogenization on the interaction between bovine casein micelles and ritonavir

PURPOSE

The aim of this work was to develop a milk-based powder formulation appropriate for pediatric delivery of ritonavir (RIT).

METHODS

Ultra-high pressure homogenization (UHPH) at 0.1, 300 and 500 MPa was used to process a dispersion of pasteurized skim milk (SM) and ritonavir. Loading efficiency was determined by RP-HPLC-UV; characterization of RIT:SM systems was carried out by apparent average hydrodynamic diameter and rheological measurements as well as different analytical techniques including Trp fluorescence, UV spectroscopy, DSC, FTIR and SEM; and delivery capacity of casein micelles was determined by in vitro experiments promoting ritonavir release.

RESULTS

Ritonavir interacted efficiently with milk proteins, especially, casein micelles, regardless of the processing pressure; however, results suggest that, at 0.1 MPa, ritonavir interacts with caseins at the micellar surface, whilst, at 300 and 500 MPa, ritonavir is integrated to the protein matrix during UHPH treatment. Likewise, in vitro experiments showed that ritonavir release from micellar casein systems is pH dependent; with a high retention of ritonavir during simulated gastric digestion and a rapid delivery under conditions simulating the small intestine environment.

CONCLUSIONS

Skim milk powder, especially, casein micelles are potentially suitable and efficient carrier systems to develop novel milk-based and low-ethanol powder formulations of ritonavir appropriate for pediatric applications.

Development of simple and rapid LC-MS/MS method for determination of celecoxib in human plasma and its application to bioequivalence study

A suitable liquid chromatography tandem mass spectrometry (LC-MS/MS) method to determine celecoxib in human plasma is needed for bioequivalence and pharmacokinetic studies of celecoxib preparations. The present study describes a simple, rapid, reproducible, and reliable LC-MS/MS method to determine celecoxib concentrations in human plasma. After one-step liquid-liquid extraction (LLE) using methyl tert-butyl ether (MTBE), celecoxib and atorvastatin (internal standard, IS) were eluted on a Luna HILIC column with an isocratic mobile phase, consisting of 10mM ammonium formate buffer (adjusted to pH 3.0 with formic acid):methanol (5:95, v/v) at a flow rate of 0.2 mL/min. The achieved lower limit of quantitation (LLOQ) was 10 ng/mL (S/N>10) and the standard calibration curve for celecoxib was linear (correlation coefficients were >0.9995) over the studied concentration range (10-2000 ng/mL). The inter- and intra-assay coefficients of variation ranged from 1.15% to 4.93% and 1.08% to 7.81%, respectively. The chromatographic run time for each plasma sample was <2 min. The developed method was successfully applied to a bioequivalence study of celecoxib in healthy Korean male volunteers.

Chromatographic techniques in analysis of cyclooxygenase-2 inhibitors in drugs and biological samples

Non-steroidal anti-inflammatory drugs, as a therapeutic class, are among the most often used active pharmaceutical ingredients in heath care in the world. They are mostly available without prescription and often used for treatment of fever and pain. An extensive research of the literature published in analytical and pharmaceutical chemistry journals has been conducted and the chromatographic methods which were used for the purity, stability and pharmacokinetic studies of the cyclooxygenase-2 inhibitors, in formulations and biological materials have been reviewed. The methodology for the analysis of selected drugs is very well documented and many examples are available in the literature. The common use of chromatographic techniques with various detection attachments provide possibility for monitoring of drugs in therapy.

Celecoxib determination in different layers of skin by a newly developed and validated HPLC-UV method

A simple, rapid and sensitive analytical procedure for the measurement of celecoxib (CXB) levels in skin samples after in vitro penetration studies was developed and validated. In vitro permeability studies in porcine skin were performed for quantification of CXB at different layers of skin, the stratum corneum (SC) and epidermis plus dermis (EP + D) as well as in the acceptor solution (AS) to assess CXB permeation through skin. CXB was quantified by HPLC using a C18 column and UV detection at 251 nm. The mobile phase was methanol-water 72:28 (v/v) and the flow-rate was 0.8 mL/min. The CXB retention time was 5 min. The assay was linear for CBX in the concentration range of 0.1-3.0 μg/mL in the AS (drug permeated through skin) and 5.0-50.0 μg/mL for drug retained in SC and [EP + D] in vitro. The linear correlation coefficients for the different calibration curves were equal or greater than 0.99. Intra- and inter-assay variabilities were below 8.0%. Extraction of CXB from skin samples showed recoveries higher than 95.0% after 15 min of ultrasonic sound and centrifugation at 2500 rpm for 3 min. The method was considered appropriate for the assay of CXB in skin samples, after in vitro cutaneous penetration studies.

Altered GABAergic neurotransmission is associated with increased kainate-induced seizure in prostaglandin-endoperoxide synthase-2 deficient mice

Excitotoxicity involves over activation of brain excitatory glutamate receptors and has been implicated in neurological, neurodegenerative and neuropsychiatric diseases. Metabolism of arachidonic acid (AA) through the phospholipase A(2) (PLA(2))/prostaglandin-endoperoxide synthase (PTGS) pathway is increased after excitotoxic stimulation. However, the individual roles of the PTGS isoforms in this process are not well established. We assessed the role of the PTGS isoforms in the process of excitotoxicity by exposing mice deficient in either PTGS-1 (PTGS-1(-/-)) or PTGS-2 (PTGS-2(-/-)) to the prototypic excitotoxin, kainic acid (KA). Seizure intensity and neuronal damage were significantly elevated in KA-exposed PTGS-2(-/-), but not in PTGS-1(-/-), mice. The increased susceptibility was not associated with an alteration in KA receptor binding activity or mediated through the CB1 endocannabinoid receptor. The frequency of spontaneous inhibitory postsynaptic currents (sIPSCs) was decreased in the CA1 pyramidal neurons of PTGS-2(-/-) mice, suggesting an alteration of GABAergic function. In wild-type mice, six weeks treatment with the PTGS-2 selective inhibitor celecoxib recapitulated the increased susceptibility to KA-induced excitotoxicity observed in PTGS-2(-/-) mice, further supporting the role of PTGS-2 in the excitotoxic process. The increased susceptibility to KA was also associated with decreased brain levels of PGE(2), a biomarker of PTGS-2 activity. Our results suggest that PTGS-2 activity and its specific products may modulate neuronal excitability by affecting GABAergic neurotransmission. Further, inhibition of PTGS-2, but not PTGS-1, may increase the susceptibility to seizures.

Quantification of infant exposure to celecoxib through breast milk

AIMS

To determine the milk-to-plasma (M/P) concentration ratio of celecoxib, and estimate likely infant exposure.

METHODS

Blood and milk were sampled for 48 h after oral administration of celecoxib 200 mg to six lactating volunteers. The M/P ratio was derived from the area under the concentration-time curves (0-infinity) and the infant 'dose' estimated from celecoxib concentrations in milk.

RESULTS

The median (range) M/P ratio was 0.18 (0.15-0.26). The median (range) infant 'dose' was 0.23% (0.17-0.30%) of the maternal dose, adjusted for weight.

CONCLUSION

The relative 'dose' of celecoxib to which infants are exposed via milk is very low, suggesting that breastfeeding during routine dosing would pose minimal risk.