Sustained-release diclofenac potassium-loaded solid lipid microparticle based on solidified reverse micellar solution: in vitro and in vivo evaluation

Objective: To formulate sustained-release diclofenac potassium-loaded solid lipid microparticles (SLMs) based on solidified reverse micellar solution (SRMS) and to evaluate the in vitro and in vivo properties.

Methods: SRMS consisting of mixtures of Phospholipon® 90H and Softisan® 154 were used to formulate diclofenac potassium-loaded SLMs. Characterization based on the particle size and morphology, stability and encapsulation efficiency (EE%) were carried out on the SLMs. In vitro release was carried out in simulated intestinal fluid (pH 7.5). Anti-inflammatory and ulcerogenic properties were studied using rats.

Results: Maximum EE% of 95%, 94% and 93% were obtained for SLMs formulated with SRMS 1:1, 2:1 and 1:2, respectively. In vitro release showed about 85–90% drug release at 13?h. Diclofenac potassium-loaded SLMs showed good anti-inflammatory and gastro-protective properties.

Conclusion: Diclofenac potassium-loaded SLMs based on SRMS could be used orally or parenterally under controlled conditions, for once daily administration.     

双氯芬酸钾喷雾剂抗炎镇痛的药效学研究

目的观察双氯芬酸钾喷雾剂的抗炎镇痛作用.方法采用二甲苯致小鼠耳肿胀、角叉菜胶致大鼠足肿胀和小鼠热板法模型观察双氯芬酸钾喷雾剂的抗炎、镇痛作用.结果双氯芬酸钾喷雾剂对二甲苯致小鼠耳肿胀和角叉菜胶致大鼠足肿胀均有明显的抑制作用,并能增加热刺激小鼠的痛阈.结论双氯芬酸钾喷雾剂具有明显的抗炎、镇痛作用,作用强度与双氯芬酸二乙胺乳胶剂相似.     

Formulation and in vitro evaluation of a PEGylated microscopic lipospheres delivery system for ceftriaxone sodium

The aim of this study was to formulate and evaluate in vitro, ceftriaxone sodium lipospheres dispersions for oral administration. Ceftriaxone sodium lipospheres were prepared by melt-emulsification using 30%w/w Phospholipon^® 90H in Softisan^® 154 as the lipid matrix containing increasing quantities of PEG 4000 (10, 20, 30, and 40%w/w). Characterization based on particle size, particle morphology, encapsulation efficiency, loading capacity and pH were carried out on the lipospheres. Microbiological studies of the ceftriaxone sodium-loaded lipospheres were performed using Escherichia coli as the model organism. In vitro permeation of ceftriaxone sodium from the lipospheres through artificial membrane (0.22?μm pore size) was carried out using Franz cell and simulated intestinal fluid (SIF) without pancreatin as acceptor medium. Photomicrographs revealed spherical particles within a micrometer range with minimal growth after 1 month (Maximum size?=?64.76?±?3.81?μm). Microbiological studies indicated that lipospheres formulated with 20%w/w of PEG 4000 containing 2%w/w or 3%w/w of ceftriaxone sodium gave significantly (p?<?0.05) higher inhibition zone diameter than those with 30%w/w or 40%w/w of PEG 4000. The result also indicated that lipospheres with 10%w/w PEG 4000 resulted in significantly higher encapsulation efficiency (p?<?0.05) while those with 30%w/w gave the least, while the loading capacity values ranged from 3.22?mg of ceftriaxone sodium/100?mg of lipid to 6.36?mg of ceftriaxone sodium/100?mg of lipid. Permeation coefficient values varied and ranged from 8.55?×?10^?7 cm/s to 2.08?×?10^?6 cm/s depending on the concentration of PEG 4000. The result of this study gave insight that the issue of ceftriaxone stability in oral formulation could be adequately addressed by tactical engineering of lipid drug delivery systems such as lipospheres.     

Evaluation of Ethanol and Aqueous extracts of Cinnamomum verum Leaf Galls for Potential Antioxidant and Analgesic activity

In the present study, ethanol and aqueous extracts of leaf galls of Cinnamomum verum were prepared to evaluate the antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging assay and superoxide radical scavenging assay with ascorbic acid as a standard, and analgesic activity by tail immersion test and acetic acid-induced writhing test methods using diclofenac sodium as the reference drug. Swiss albino mice maintained under standard laboratory conditions were used for analgesic tests. In the 2,2-diphenyl-1-picrylhydrazyl assay it was found that the aqueous and the ethanol extract possessed almost equal capacity to inhibit free radicals (IC₅₀=13.3 and 13.53 µg/ml) but found less than ascorbic acid (IC₅₀=9.96 µg/ml). And in superoxide assay the ethanol extract was found to be more potent in scavenging super oxide radicals when compared to ascorbic acid and the aqueous extract (IC₅₀=237.1 and 197.8 µg/ml) with the IC₅₀=119.7 µg/ml. For analgesic activity, ethanol extract showed the maximum time required for response against thermal stimuli (6.75±0.47 s) and maximum % of writhing inhibition (44.57%) when compared to aqueous extract (5.25±0.48 s and 32.61%), whereas diclofenac showed response in 7.25±0.25 s 67.39% inhibition in tail immersion and writhing tests, respectively. These results demonstrate that the ethanol extracts of leaf galls possessed high antioxidant and analgesic activity.     

Review of diclofenac and evaluation of its place in therapy as a nonsteroidal antiinflammatory agent

Diclofenac sodium is a nonsteroidal antiinflammatory drug (NSAID) that has been used in 120 countries since its introduction in Japan in 1974. It is currently the eighth largest-selling drug and the most frequently used NSAID in the world. Diclofenac, a phenylacetic acid derivative, is a potent inhibitor of cyclooxygenase enzyme activity, and may also interact with the lipoxygenase enzyme pathway, and with the release and reuptake of arachidonic acid. Diclofenac is almost completely absorbed, highly protein-bound, penetrates well into synovial fluid, and is extensively metabolized. Comparative studies have shown that diclofenac is at least equivalent in efficacy to aspirin and other NSAID when used for the treatment of rheumatic diseases such as rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. Diclofenac also possesses potent analgesic properties. Clinical trials suggest that diclofenac has a favorable side-effect profile, excellent patient tolerability, and a lower patient dropout rate when compared with aspirin and other NSAID.     

Increased absorption rate of diclofenac from fast acting formulations containing its potassium salt.

Diclofenac (CAS 15307-86-5) is a non-steroidal anti-inflammatory drug largely used, mainly to relief pain of various origin. Diclofenac is present on the market as free acid, as sodium salt (CAS 15307-79-6) and as potassium salt (CAS 15307-81-0). The last salification form has shown a prompter absorption rate and a faster onset of analgesic activity than the acid form and sodium salt. This paper extensively reviews three trials carried out on healthy volunteers, where potassium salt of diclofenac present in three fast-acting formulations, namely sachets (Trial 1), tablets (Trial 2) and oral drops (Trial 3), were compared to reference tablet formulations from the market. A very fast absorption rate was encountered with the three test formulations, with the peak reached in one case 5 min and in most cases within 10-15 min after dosing. The quick absorption rate of test formulations was attributed to the special combination of the salt of diclofenac with a dynamic buffering agent, namely bicarbonate, present in the test formulations and covered by an international patent. The prompt absorption of diclofenac from the new fast-acting formulations was accompanied by the presence of only one peak, whereas the reference formulations produced in most cases two peaks, as widely described in literature. This finding suggested the hypothesis that the absorption of test formulations should occur in a shorter tract of the gut. The faster absorption of diclofenac from the three fast-acting formulations is expected to produce a faster onset of analgesic action, which highlights these new formulations as particularly indicated to relief pain of any origin.     

Population pharmacokinetics of oral diclofenac for acute pain in children

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Diclofenac is an effective oral analgesic for acute postoperative pain. In adults 25 mg is half as effective as 50 mg, but 50 mg and 100 mg are similarly effective (ceiling effect). Diclofenac has linear pharmacokinetics in this range.
• Diclofenac is frequently used ‘off-label’ in children for acute pain but optimum dosing is unclear (dosing of diclofenac in clinical paediatric studies ranges from 0.5–2.5 mg kg⁻¹). There is currently no licensed oral paediatric formulation of diclofenac.

WHAT THIS STUDY ADDS

• Using a new diclofenac oral suspension, a dose of 1 mg kg⁻¹ in children aged 1 to 12 years gives a similar exposure to 50 mg in adults; paediatric patients are unlikely to benefit from higher doses.

AIMS

To develop a population pharmacokinetic model for a new diclofenac suspension (50 mg 5 ml⁻¹) in adult volunteers and paediatric patients, and recommend a dose for acute pain in children.

METHODS

Blood samples were drawn at the start and end of surgery, and on removal of the venous cannula from 70 children (aged 1 to 12 years, weight 9 to 37 kg) who received a preoperative oral 1 mg kg⁻¹ dose; these were pooled with rich (14 post-dose samples) data from 30 adult volunteers. Population pharmacokinetic modelling was undertaken with NONMEM. The optimum adult dose of diclofenac for acute pain is 50 mg. Simulation from the final model was performed to predict a paediatric dose to achieve a similar AUC to 50 mg in adults.

RESULTS

A total of 558 serum diclofenac concentrations from 100 subjects was used in the pooled analysis. A single disposition compartment model with first order elimination and dual absorption compartments was used. The estimates of CL/F and V_D/F were 53.98 l h⁻¹ 70 kg⁻¹ and 4.84 l 70 kg⁻¹ respectively. Allometric size models appeared to predict adequately changes in CL and V_D with age. Of the simulated doses investigated, 1 mg kg⁻¹ gave paediatric AUC_{(0, 12 h)} to adult 50 mg AUC_{(0, 12 h)} ratios of 1.00, 1.08 and 1.18 for ages 1–3, 4–6 and 7–12 years respectively.

CONCLUSIONS

This study has shown 1 mg kg⁻¹ diclofenac to produce similar exposure in children aged 1 to 12 years as 50 mg in adults, and is acceptable for clinical practice; patients are unlikely to obtain further benefit from higher doses.     

Microsponges based novel drug delivery system for augmented arthritis therapy

The motive behind present work was to formulate and evaluate gel containing microsponges of diclofenac diethylamine to provide prolonged release for proficient arthritis therapy. Quasi-emulsion solvent diffusion method was implied using Eudragit RS-100 and microsponges with varied drug–polymer ratios were prepared. For the sake of optimization, diverse factors affecting microparticles physical properties were too investigated. Microsponges were characterized by SEM, DSC, FT-IR, XRPD and particle size analysis, and evaluated for morphology, drug loading, in vitro drug release and ex vivo diffusion as well. There were no chemical interactions between drug and polymers used as revealed by compatibility studies outcomes. The drug polymer ratio reflected notable effect on drug content, encapsulation efficiency and particle size. SEM results revealed spherical microsponges with porous surface, and had 7.21 μm mean particle size. The microsponges were then incorporated in gel; which exhibited viscous modulus along with pseudoplastic behavior. In vitro drug release results depicted that microsponges with 1:2 drug–polymer ratio were more efficient to give extended drug release of 75.88% at the end of 8 h; while conventional formulation get exhausted incredibly earlier by releasing 81.11% drug at the end of 4 h only. Thus the formulated microsponge-based gel of diclofenac diethylamine would be a promising alternative to conventional therapy for safer and efficient treatment of arthritis and musculoskeletal disorders.     

Transdermal absorption enhancing effect of the essential oil of Rosmarinus officinalis on percutaneous absorption of Na diclofenac from topical gel

Abstract

Context: Rosemary essential oil has been used topically for several purposes (analgesic, anti acne, and anti-inflammatory) in Iranian traditional medicine.

Objectives: This investigation aimed to study the effect of essential oil of Rosmarinus officinalis L. (Lamiaceae) on the transdermal absorption of Na diclofenac from topical gel.

Material and methods: Diclofenac sodium topical gel was prepared with HPMC K4M and Carbopol 934P as a gelling agent, and several vehicles. The most stable gel was chosen and enhancing effects of the essential oil with different concentrations (0.1, 0.5, and 1.0% w/w) on the permeation of diclofenac were evaluated. The anti-nociceptive effect of preparations was evaluated based on the formalin and tail flick tests in mice.

Results: The major constituents of the essential oil were 1,8-cineol (15.96%), α-pinene (13.38%), camphor (7.87%), bornyl acetate (6.54%), verbenone (5.82%), borneol (5.23%), camphene (4.96%), and (E)-caryophyllene (3.8%). Topical diclofenac containing 0.5% essential oil showed more analgesic effect after 25, 30, and 35?min (p?<?0.001) than the reference drug in the tail flick test. The analgesic effect of preparation containing 1% essential oil was more than reference gel after 15?min (p?<?0.05). This difference was observed after 20, 25, 30, 35, and 40?min (p?<?0.001) too. Rosemary essential oil 1% promoted analgesic effect of drug in comparison with diclofenac gel in the formalin early phase (p?<?0.05). The enhancing effect of rosemary was observed in 0.5 and 1% concentration (p?<?0.05 and p?<?0.001, respectively) in the late phase.

Conclusion: This study proved the enhancing effect of 0.5 and 1% of rosemary essential oil on diclofenac percutaneous absorption.     

An observer-blind comparison of diclofenac potassium, piroxicam and placebo in the treatment of ankle sprains

An observer-blind comparative clinical study was carried out in 108 patients presenting with ankle sprains at an Accident and Emergency department. The efficacy and tolerability of diclofenac potassium (50 mg 3-times daily) was compared with that of piroxicam (20 mg once daily), and placebo. Patients were allocated at random to receive one or other of the three treatments for 7 days. There were 36 patients in each group. The analgesic and anti-inflammatory effects of treatment were assessed from volumetric measurements of inflammation at the injured ankle, tenderness, pain on passive movement, severity of the joint lesion, severity of pain at rest and on movement. The overall reductions in pain and inflammation were assessed at the end of the study. The results in patients treated with diclofenac potassium were significantly better than those in patients treated with piroxicam with respect to the improvement in pain on walking and the overall reduction in pain and inflammation, and both active treatments were superior to placebo. There was no significant difference between diclofenac potassium and piroxicam with respect to inflammation measured by volumetry, tenderness, and severity of pain at rest, but both active treatments were consistently superior to placebo. No serious adverse effects were reported. All the patients treated with diclofenac potassium and all those treated with piroxicam said that they would be willing to take the drug again; this was the case with only 27.8% of the placebo group. Diclofenac potassium can be considered an effective treatment for acute ankle sprains with a rapid onset of analgesic and anti-inflammatory action and good tolerability.     

Transport of diclofenac by breast cancer resistance protein (ABCG2) and stimulation of multidrug resistance protein 2 (ABCC2)-mediated drug transport by diclofenac and benzbromarone

Diclofenac is an important analgesic and anti-inflammatory drug, widely used for treatment of postoperative pain, rheumatoid arthritis, and chronic pain associated with cancer. Consequently, diclofenac is often used in combination regimens and undesirable drug-drug interactions may occur. Because many drug-drug interactions may occur at the level of drug transporting proteins, we studied interactions of diclofenac with apical ATP-binding cassette (ABC) multidrug efflux transporters. Using Madin-Darby canine kidney (MDCK)-II cells transfected with human P-glycoprotein (P-gp; MDR1/ABCB1), multidrug resistance protein 2 (MRP2/ABCC2), and breast cancer resistance protein (BCRP/ABCG2) and murine Bcrp1, we found that diclofenac was efficiently transported by murine Bcrp1 and moderately by human BCRP but not by P-gp or MRP2. Furthermore, in Sf9-BCRP membrane vesicles diclofenac inhibited transport of methotrexate in a concentration-dependent manner. We next used MDCK-II-MRP2 cells to study interactions of diclofenac with MRP2-mediated drug transport. Diclofenac stimulated paclitaxel, docetaxel, and saquinavir transport at only 50 microM. We further found that the uricosuric drug benzbromarone stimulated MRP2 at an even lower concentration, having maximal stimulatory activity at only 2 microM. Diclofenac and benzbromarone stimulated MRP2-mediated transport of amphipathic lipophilic drugs at 10- and 250-fold lower concentrations, respectively, than reported for other MRP2 stimulators. Because these concentrations are readily achieved in patients, adverse drug-drug interactions may occur, for example, during cancer therapy, in which drug concentrations are often critical and stimulation of elimination via MRP2 may result in suboptimal chemotherapeutic drug concentrations. Moreover, stimulation of MRP2 activity in tumors may lead to increased efflux of chemotherapeutic drugs and thereby drug resistance.     

Development and evaluation of natural gum-based extended release matrix tablets of two model drugs of different water solubilities by direct compression

The study was aimed at developing extended release matrix tablets of poorly water-soluble diclofenac sodium and highly water-soluble metformin hydrochloride by direct compression using cashew gum, xanthan gum and hydroxypropylmethylcellulose (HPMC) as release retardants. The suitability of light grade cashew gum as a direct compression excipient was studied using the SeDeM Diagram Expert System. Thirteen tablet formulations of diclofenac sodium (∼100 mg) and metformin hydrochloride (∼200 mg) were prepared with varying amounts of cashew gum, xanthan gum and HPMC by direct compression. The flow properties of blended powders and the uniformity of weight, crushing strength, friability, swelling index and drug content of compressed tablets were determined. In vitro drug release studies of the matrix tablets were conducted in phosphate buffer (diclofenac: pH 7.4; metformin: pH 6.8) and the kinetics of drug release was determined by fitting the release data to five kinetic models. Cashew gum was found to be suitable for direct compression, having a good compressibility index (ICG) value of 5.173. The diclofenac and metformin matrix tablets produced generally possessed fairly good physical properties. Tablet swelling and drug release in aqueous medium were dependent on the type and amount of release retarding polymer and the solubility of drug used. Extended release of diclofenac (∼24 h) and metformin (∼8–12 h) from the matrix tablets in aqueous medium was achieved using various blends of the polymers. Drug release from diclofenac tablets fitted zero order, first order or Higuchi model while release from metformin tablets followed Higuchi or Hixson-Crowell model. The mechanism of release of the two drugs was mostly through Fickian diffusion and anomalous non-Fickian diffusion. The study has demonstrated the potential of blended hydrophilic polymers in the design and optimization of extended release matrix tablets for soluble and poorly soluble drugs by direct compression.     

Diclofenac sodium

The pharmacology, pharmacokinetics, clinical efficacy, adverse effects, and dosage of diclofenac sodium are reviewed. Diclofenac, the first nonsteroidal anti-inflammatory agent (NSAID) to be approved that is a phenylacetic acid derivative, competes with arachidonic acid for binding to cyclo-oxygenase, resulting in decreased formation of prostaglandins. The drug has both analgesic and antipyretic activities. Diclofenac is efficiently absorbed from the gastrointestinal tract; peak plasma concentrations occur 1.5 to 2.0 hours after ingestion in fasting subjects. Even though diclofenac has a relatively short elimination half-life in plasma (1.5 hours), it persists in synovial fluid. The drug is metabolized in the liver and is eliminated by urinary and biliary excretion. In clinical trials, diclofenac was as effective as aspirin, diflunisal, indomethacin, sulindac, ibuprofen, ketoprofen, and naproxen in improving function and reducing pain in patients with rheumatoid arthritis. For treatment of osteoarthritis, diclofenac was equivalent in efficacy to aspirin, diflunisal, indomethacin, sulindac, ibuprofen, ketoprofen, naproxen, flurbiprofen, mefenamic acid, and piroxicam. Diclofenac was as effective as indomethacin or sulindac in treating ankylosing spondylitis. The most frequent adverse effects reported for diclofenac were gastrointestinal, but these effects were fewer and less serious than occurred with aspirin or indomethacin; in addition, diclofenac caused fewer central nervous system reactions than indomethacin. Diclofenac is administered in divided doses with meals. The recommended total daily dosage is 100 to 150 mg (osteoarthritis and ankylosing spondylitis) or 150 to 200 mg (rheumatoid arthritis). Diclofenac is effective, but no more so than other NSAIDs. It is structurally distinct and offers another choice in the treatment of rheumatological conditions.     

Rapid and Sensitive Reverse-phase High-performance Liquid Chromatography Method for Estimation of Ketorolac in Pharmaceuticals Using Weighted Regression

A reliable, rapid and sensitive isocratic reverse phase high-performance liquid chromatography method has been developed and validated for assay of ketorolac tromethamine in tablets and ophthalmic dosage forms using diclofenac sodium as an internal standard. An isocratic separation of ketorolac tromethamine was achieved on Oyster BDS (150×4.6 mm i.d., 5 μm particle size) column using mobile phase of methanol:acetonitrile:sodium dihydrogen phosphate (20 mM; pH 5.5) (50:10:40, %v/v) at a flow rate of 1.0 ml/min. The eluents were monitored at 322 nm for ketorolac and at 282 nm for diclofenac sodium with a photodiode array detector. The retention times of ketorolac and diclofenac sodium were found to be 1.9 min and 4.6 min, respectively. Response was a linear function of drug concentration in the range of 0.01-15 μg/ml (R²=0.994; linear regression model using weighing factor 1/x²) with a limit of detection and quantification of 0.002 μg/ml and 0.007 μg/ml, respectively. The % recovery and % relative standard deviation values indicated the method was accurate and precise.     

Diclofenac readily penetrates the cerebrospinal fluid in children

AIMS

The primary aim was to study the cerebrospinal fluid (CSF) penetration of intravenous diclofenac in children. The secondary aim was to evaluate the plasma diclofenac concentration at the onset of wound pain after inguinal surgery in children.

METHODS

A total of 31 children (24 boys) aged 3 months to 12 years received a single intravenous injection of diclofenac 1 mg kg⁻¹. Paired CSF and blood samples were obtained 5 min to 22 h (median 69 min) later. In children having inguinal surgery a second blood sample was obtained at the time that the children felt wound pain for the first time after surgery. Diclofenac concentrations in CSF, plasma and protein free plasma were measured by gas chromatography with mass spectrometric detection.

RESULTS

In the 28 CSF samples obtained at 5 min to 3 h 43 min after injection, diclofenac concentrations ranged between 0.5 and 4.7 μg l⁻¹. At 5.5 h the CSF concentration was 0.1 μg l⁻¹, and no diclofenac was detected in the two CSF samples obtained at 22 h. The median of plasma diclofenac concentration at the time when pain returned after inguinal surgery was 104 μg l⁻¹ (range 70–272 μg l⁻¹). No serious or unexpected adverse effects were reported.

CONCLUSIONS

Diclofenac penetrates the CSF rapidly, and a sufficient concentration to inhibit cyclooxygenase enzymes is sustained for up to 4 h.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Diclofenac, a nonselective nonsteroidal anti-inflammatory drug,, exerts analgesic action both in the peripheral tissues and in the central nervous system by inhibiting cyclooxygenase enzymes COX-1/2, but central nervous system penetration of diclofenac has not been evaluated in humans.

WHAT THIS STUDY ADDS

• Diclofenac penetrates the cerebrospinal fluid rapidly, and after a single intravenous dose of 1 mg kg⁻¹, sufficient concentrations to inhibit COX-1/2 are sustained for up to 4 h.

     

Diclofenac, a Non-steroidal Anti-inflammatory Drug, Inhibits L-type Ca2+ Channels in Neonatal Rat Ventricular Cardiomyocytes

A non-steroidal anti-inflammatory drug (NSAID) has many adverse effects including cardiovascular (CV) risk. Diclofenac among the nonselective NSAIDs has the highest CV risk such as congestive heart failure, which resulted commonly from the impaired cardiac pumping due to a disrupted excitation-contraction (E-C) coupling. We investigated the effects of diclofenac on the L-type calcium channels which are essential to the E-C coupling at the level of single ventricular myocytes isolated from neonatal rat heart, using the whole-cell voltage-clamp technique. Only diclofenac of three NSAIDs, including naproxen and ibuprofen, significantly reduced inward whole cell currents. At concentrations higher than 3 µM, diclofenac inhibited reversibly the Na⁺ current and did irreversibly the L-type Ca²⁺ channels-mediated inward current (IC₅₀=12.89±0.43 µM) in a dose-dependent manner. However, nifedipine, a well-known L-type channel blocker, effectively inhibited the L-type Ca²⁺ currents but not the Na⁺ current. Our finding may explain that diclofenac causes the CV risk by the inhibition of L-type Ca²⁺ channel, leading to the impairment of E-C coupling in cardiac myocytes.     

Eudragit? Microparticles for the Release of Budesonide: A Comparative Study

This study compares the behaviour of budesonide-containing microparticles made of Eudragit^®RS or Eudragit^®RS/Eudragit^®RL 70:30 (w/w) prepared either by solvent evaporation or spray-drying technique. The loading efficiency of budesonide within microparticles was about 72% for microparticles prepared by solvent evaporation and around 78% for spray-dried microparticles. Thermal analyses were assessed to collect information about the structural stability of budesonide within the polymeric microspheres. The in vitro release was performed using simulating gastric (fasted state simulated gastric fluid) and intestinal (fasted state simulated intestinal fluid) fluids as the receiving solutions. After 3 h the drug release from Eudragit^®RS/Eudragit^®RL microparticles was about 6-fold higher than that obtained in the case of monopolymer microparticles. Using fasted state simulated intestinal fluid the drug was released between 4 and 30% in both types of preparations. Eudragit^®RS microparticles showed a better protection of the drug from gastric acidity than those of Eudragit^®RS/Eudragit^®RL allowing us to propose Eudragit^®RS microparticles as a hypothetical system of colon specific controlled delivery.     

Development of diclofenac sodium-loaded alginate-PVP K 30 microbeads using central composite design

Background and the purpose of the study

Diclofenac sodium is a non-steroidal anti-inflammatory agent with a short biological half-life (1–2 hr) and requires multiple dosing. This research was carried out to develop and optimize diclofenac sodium loaded alginate-PVP K 30 microbeads to eliminate the need for multiple dosing and adverse effects.

Methods

Diclofenac sodium loaded alginate-PVP K 30 microbeads were prepared by ionotropic gelation. Particle size, drug release, swelling, FTIR and SEM analyses were performed.

Results

Optimized microbeads showed particle size of 0.589±0.054 to 0.620±0.067 mm, and drug entrapment efficiency of 97.88±2.86 to 98.60±3.55%. The in vitro drug release from microbeads was sustained over 10 hrs and followed controlled-release pattern. FTIR analysis indicated the possibility of intermolecular hydrogen bonding interactions, i.e., –OH…O=C in microbeads.

Conclusion

Microbeads for oral controlled delivery of diclofenac sodium were successfully developed by ionotropic gelation.     

An exploratory microdialysis study investigating the effect of repeated application of a diclofenac epolamine medicated plaster on prostaglandin concentrations in skeletal muscle after standardized physical exercise

Aim

Muscle injuries and extensive exercise are associated with cyclo-oxygenase dependent formation of inflammatory prostaglandins. Since the effect of topical administration of non-steroidal anti-inflammatory drugs (NSAIDs) on local cyclo-oxygenase is unknown, the present exploratory, open label, non-randomized study set out to measure exercise induced release of prostaglandins before and after epicutaneous administration of diclofenac.

Methods

Microdialysis was used to determine the local interstitial concentration of PGE₂ and 8-iso-PGF_2α as well as diclofenac concentrations in the vastus lateralis under rest, dynamic exercise and during recovery in 12 healthy subjects at baseline and after a treatment phase applying a total of seven plasters medicated with 180 mg of diclofenac epolamine over 4 days.

Results

At baseline PGE₂ concentrations were 1169 ± 780 pg ml⁻¹ at rest and 1287 ± 459 pg ml⁻¹ during dynamic exercise and increased to 2005 ± 1126 pg ml⁻¹ during recovery. After treatment average PGE₂ concentrations were 997 ± 588 pg ml⁻¹ at rest and 1339 ± 892 pg ml⁻¹ during exercise. In contrast with the baseline phase no increase in PGE₂ concentrations was recorded during the recovery period after treatment (PGE₂ 1134 ± 874 pg ml⁻¹). 8-iso-PGF_2α was neither affected by exercise nor by treatment with diclofenac. Local and systemic concentrations of diclofenac were highly variable but comparable with previous clinical pharmacokinetic studies.

Conclusions

We can hypothesize an effect of topical diclofenac epolamine plaster on limiting the increase of local concentrations of the pro-inflammatory prostaglandin PGE₂ induced in the muscle of healthy human subjects following standardized physical exercise. No effect of diclofenac treatment on 8-iso-PGF_2α concentrations was observed, mainly since isoprostane is produced by a free radical-catalyzed lipid peroxidation mechanism independent of cyclo-oxygenases.     

Protective effect of the ethanolic and methanolic leaf extracts of Madhuca longifolia against diclofenac-induced toxicity in female Wistar albino rats

BackgroundDiclofenac is commonly prescribed Non-Steroidal Anti-Inflammatory Drug (NSAIDs) as it has anti-inflammatory, analgesic and anti-pyretic properties. Long term usage and over-dosage of diclofenac is associated with adverse effects like drug-induced liver injury, gastrointestinal and renal toxicity. The therapeutic uses of medicinal plants have gained a prominent role in recent years. Madhuca longifolia is a tree found throughout India, which is known to have several pharmacological activities. The aim of our study is to investigate the potential effect of the ethanolic and methanolic leaf extracts of M. longifolia against diclofenac-induced toxicity.MethodsThe rats used for the experiment were divided into seven groups. Group-1 was the normal control. Group-2 was administered with diclofenac (50 mg/kg b.w./day/ip) on the 4^th and the 5^th day. Group-3 was treated with diclofenac and ELEML (500 mg/kg b.w./day/po) on all 5 days. Group-4 was treated with diclofenac and MLEML (500 mg/kg b.w./day/po) on all 5 days. Standard drug silymarin (25 mg/kg b.w./day/po) was given to the rats of group-5 along with diclofenac. Group-6 and group–7 were treated with ethanolic leaf extract and methanolic leaf extract of M. longifolia respectively. After the study period, the rats were evaluated for parameters like liver and renal markers, antioxidants and histopathological changes.ResultsThis study has proved the beneficial effect of ethanolic and methanolic leaf extract of M. longifolia against diclofenac-induced toxicity wherein ethanolic leaf extract showed a better result than methanolic leaf extract.ConclusionOur study has concluded the beneficial effect of ethanolic and methonolic leaf extract of Madhuca longifolia against DFC-induced toxicity. This study proves that it has potential effect on hepato, renal and gastro toxicity in female Wistar albino rats. It can further be studied to understand its mechanism in treating toxicity.