Comparative bioavailability of diclofenac hydroxyethylpyrrolidine vs diclofenac sodium in man

Summary A pharmacokinetic study in man has been made of a new dosage form of diclofenac hydroxyethylpyrrolidine (DIEP); soluble salt packed in sachets was compared with diclofenac sodium as enteric coated tablets.Oral DIEP 2×50 mg showed a significant difference in absorption kinetics (ka, lag time and t_max) as compared to oral diclofenac sodium 2×50 mg. A relevant plasma concentration of diclofenac was detected just 15 min after DIEP, while diclofenac sodium produced a measurable plasma concentration only 0.5–1 h after the treatment. C_max and t_1/2 after DIEP and diclofenac sodium were comparable. Comparison of the two AUC values showed that DIEP was bioequivalent to diclofenac sodium (Q=100%).     

Pharmacokinetics of diclofenac sodium after intramuscular administration in combination with triamcinolone acetate

Summary Seventy-five mg diclofenac sodium were given intramuscularly to 15 subjects alone and in combination with 40 mg triamicinolone acetate. Plasma levels of diclofenac were measured and pharmacokinetic parameters were calculated. The results indicate no statistically significant differences for most of the parameters. The maximum plasma concentrations (Cp_max) was increased by about 20% in combination with the glucocorticoid, whereas terminal elimination rate did not change significantly.     

Pharmacokinetic-pharmacodynamic modeling of diclofenac in normal and Freund's complete adjuvant-induced arthritic rats

Aim:

To characterize pharmacokinetic-pharmacodynamic modeling of diclofenac in Freund''s complete adjuvant (FCA)-induced arthritic rats using prostaglandin E₂ (PGE₂) as a biomarker.

Methods:

The pharmacokinetics of diclofenac was investigated using 20-day-old arthritic rats. PGE₂ level in the rats was measured using an enzyme immunoassay. A pharmacokinetic-pharmacodynamic (PK-PD) model was developed to illustrate the relationship between the plasma concentration of diclofenac and the inhibition of PGE₂ production. The inhibition of diclofenac on lipopolysaccharide (LPS)-induced PGE₂ production in blood cells was investigated in vitro.

Results:

Similar pharmacokinetic behavior of diclofenac was found both in normal and FCA-induced arthritic rats. Diclofenac significantly decreased the plasma levels of PGE₂ in both normal and arthritic rats. The inhibitory effect on PGE₂ levels in the plasma was in proportion to the plasma concentration of diclofenac. No delay in the onset of inhibition was observed, suggesting that the effect compartment was located in the central compartment. An inhibitory effect sigmoid I_max model was selected to characterize the relationship between the plasma concentration of diclofenac and the inhibition of PGE₂ production in vivo. The I_max model was also used to illustrate the inhibition of diclofenac on LPS-induced PGE₂ production in blood cells in vitro.

Conclusion:

Arthritis induced by FCA does not alter the pharmacokinetic behaviors of diclofenac in rats, but the pharmacodynamics of diclofenac is slightly affected. A PK-PD model characterizing an inhibitory effect sigmoid I_max can be used to fit the relationship between the plasma PGE₂ and diclofenac levels in both normal rats and FCA-induced arthritic rats.     

Pharmacokinetic comparison of an oral diclofenac potassium liquid-filled soft gelatin capsule with a diclofenac potassium tablet

Objective: To compare the pharmacokinetic profiles of diclofenac potassium liquid-filled soft gelatin capsules (DPSGC) using patented ProSorb^® dispersion technology with an immediate-release, diclofenac potassium 50-mg comparator tablet in two open-label, single-dose, randomized, crossover relative bioavailability studies in healthy volunteers. Methods: In Study 1, volunteers (n = 21) received DPSGC 50 mg or a diclofenac potassium 50-mg comparator tablet in two inpatient study periods. In Study 2 (n = 54), volunteers received DPSGC 25 mg, DPSGC 50 mg, or a diclofenac potassium 50-mg comparator immediate-release tablet in three inpatient study periods. Results: In both studies, DPSGC 50 mg displayed a significantly shorter T_max and higher C_max than the 50-mg diclofenac potassium comparator tablet. DPSGC 25 mg (Study 2) produced a shorter T_max (0.45 h) and an equivalent C_max (1125 ng/ml) to the 50-mg comparator drug. Plasma diclofenac concentration–time courses for the diclofenac potassium 50-mg comparator tablet showed many low, delayed, or multiple peaks compared with DPSGC treatments. Conclusions: DPSGC 25 mg and 50 mg were more rapidly and consistently absorbed than diclofenac potassium 50-mg comparator tablets. The C_max of DPSGC 25 mg was equivalent to the 50-mg diclofenac potassium comparator tablet. These characteristics may be beneficial when fast, consistent drug absorption is needed.     

Pharmacokinetic profile of a new formulation of injection diclofenac designed for intradeltoid use

Objective: Injection diclofenac sodium available at present as a 3-ml formulation is administered intragluteally. Standard needles may not reach the gluteus maximus muscle in many cases, especially in obese patients. Alternative sites like the deltoid have been suggested to be more suitable for these patients. Diclofenac sodium 75 mg/ml was prepared to facilitate intradeltoid adminis-tration. The objective of this study was to determine pharmacokinetic parameters and to compare the bioavailability of the new formulation of injection diclofenac sodium (75 mg/ml), given as an intradeltoid injection, with the reference formulation (75mg/3 ml) given intragluteally. Research design/methods: A single-dose, two-way bioequivalence study was carried out in 18 healthy, Indian, male volunteers with a washout period of 5 days. Blood samples were collected up to 6 h after drug administration and analyzed using a prevalidated HPLC method. Results: The mean C_max and T_max, for the test and reference formulations were 1.95 μg/ml, 1.89 μg/ml and 0.39 h, 0.43 h respectively. AUC values from 0 to last measurable time point ‘t’ observed for test and reference formulations were 3.37 μg.h/ml and 3.28 μg.h/ml respectively. The mean AUC 0 – infinity for test and reference formulations was 3.57 μg.h/ml and 3.52 μg.h/ml. Conclusion: Results suggest that the test and reference formulations of injection diclofenac sodium 75 mg given intradeltoid and intragluteally are bioequivalent. The test formulation would be especially helpful in the management of obese/overweight patients and patients with thick subcutaneous fat in the gluteal region. It would increase the success rate of intramuscular deposition of the medication.     

双氯芬酸钾的人体药代动力学特点研究

采用反相高效液相色谱法测定双氯芬酸钾盐的血浆药物浓度,通过与双氯芬酸钠比较,研究双氯芬酸钾粉剂在人体内药动学过程的特点。结果表明,双氯芬酸钾与双氯芬酸钠在吸收速度及程度方面相比,双氯芬酸钾有较稳定的吸收过程,Tmax及AUC值的个体差异较双氯芬酸钠小(变异系数小)。受试者口服双氯芬酸钠无明显双峰曲线现象。提示双氯芬酸钾的体内吸收过程较双氯芬酸钠有一定的优点。     

Biodistribution of diclofenac following repeated topical applications of two diclofenac sodium formulations to minipigs

This study evaluated diclofenac concentrations in plasma, selected hind limb tissues and synovial fluid after repeated topical applications of two diclofenac formulations. Group 1 Gottingen minipigs (n = 18) were administered diclofenac sodium 2.0% topical solution twice daily on days 1–6 and once on day 7. Group 2 minipigs (n = 18) were administered diclofenac sodium 1.5% topical solution four times daily on days 1–6 and twice on day 7. Approximately 20 mg of diclofenac was applied daily to a 10 × 15 cm dosing site centered over the patella of the right knee. Plasma and tissue samples were collected throughout and analysed for diclofenac concentrations using liquid chromatography with tandem mass spectrometry. On day 1, diclofenac sodium 2.0% topical solution produced higher plasma concentrations compared with the 1.5% formulation; however, after 24 h and throughout the remainder of the dosing period, plasma concentrations appeared similar, except at the 72 h time point. Twenty‐four hours after the final application, skin treated with diclofenac sodium 2.0% topical solution retained a significantly (p < 0.02) greater amount of diclofenac than the 1.5% formulation. Generally, both formulations produced similar diclofenac concentrations in synovial fluid, underlying muscle, tendon and bone 24 h after the last application. The 2.0% diclofenac formulation applied twice daily delivered similar amounts of diclofenac as the 1.5% formulation administered four times daily. The skin retained a significant portion of the applied dose to serve as a depot for continuous diffusion of diclofenac into underlying tissues and systemic circulation. Copyright © 2013 John Wiley & Sons, Ltd.     

Pharmacokinetics and bioavailability of diclofenac in the rat

Diclofenac sodium is a widely used drug with interesting absorption and disposition features when administered to laboratory animals. The present study was undertaken to assess the pharmacokinetics of the drug after iv and gastrointestinal dosing to rats. Renal excretion of unchanged drug was negligible, but biliary excretion of the drug (unchanged and conjugated) was detected in bile duct-cannulated rats; it accounted for 27.2 and 31.2% of the total dose following iv and intraduodenal administration, respectively. Most of the drug excreted in the bile was conjugated diclofenac; unchanged drug accounted for only 4.7 and 5.4% of total diclofenac excreted in the bile after iv and intraduodenal dosing, respectively. In normal animals, intestinal absorption of the drug excreted in the bile resulted in higher drug concentrations in plasma than those obtained in bile duct-cannulated rats, but only after 60 min of dosing. When administered directly into the duodenum, diclofenac absorption was extremely fast and the maximum plasma diclofenac concentration was reached within 2 min. After oral dosing, an early peak was also observed, but it was lower than that obtained after intraduodenal dosing: 71% diclofenac hioavailability was found in bile duct-cannulated rats intraduodenally dosed, whereas in normal animals dosed by mouth a bioavailability of 79% was obtained. In normal animals intraduodenally dosed, an apparent bioavailability of 106% was observed. All of these features, particularly the influence of enterohepatic circulation on drug bioavailability, are discussed.The present work is part of a research project developed with a grant for the Plan Nacional de I + D (FAR 90-0092) of the Ministry of Industry and Energy of Spain.     

双氯芬酸钠缓释片的人体生物等效性考察

目的研究双氯芬酸钠缓释片在健康人体内的药物动力学及其相对生物利用度。方法20名健康男性受试者随机分为2组,根据交叉试验设计方案,单次给予和多次给予两种双氯芬酸钠缓释制剂,采用HPLC法测定其血药浓度,并计算药物动力学参数。结果口服单次给药的药物动力学参数计算结果显示,血浆中受试制剂和参比制剂的AUC0-t分别为(2 103.0±651.7)和(2 264.5±731.9)μg.h.L-1,以AUC0-t计算,受试制剂的相对生物利用度为(95.4±21.8)%。口服多次给药的药物动力学参数计算结果显示,血浆中受试制剂和参比制剂的AUCss分别为(2 922.5±398.6)和(2 843.6±429.4)μg.h.L-1,受试制剂的DF/τ为参比制剂的(102.8±18.0)%,以AUCss计算,受试制剂的相对生物利用度为(103.5±10.3)%。结论统计学分析结果表明受试制剂和参比制剂具有生物等效性。     

Pharmacokinetics of dicrofenac after its intrarectal and intracolostomal administration to rabbits with rectal resection or colostoma construction.

We investigated the pharmacokinetics of diclofenac, one of the important analgesics in palliative care, after its intrarectal and intracolostomal administration to rabbits with rectal resection or colostoma construction. In rectal-resected rabbits, its bioavailability after rectal administration was significantly lower than that in normal rabbits, and furthermore that after intracolostomal administration was significantly lower than that in rectal-resected rabbits. This decreased bioavailability in rabbits with rectal resection and colostoma construction was thought to be due to the increased first-pass effect. With increase in the dose up to 1.5-fold, the plasma concentrations in both rectal-resected and colostoma-constructed rabbits increased to the normal rabbit level. These results indicate that the bioavailability of diclofenac sodium after its rectal and intracolostomal administration decreases, and that an increased dose can restore the decreased plasma concentration. There was no difference in the plasma concentration with diclofenac sodium suppositories between administration into the normal rectum and the remaining rectum following colostoma construction, and the remaining rectum was found to be a useful administration route for suppositories. Therefore, it was indicated that when administering diclofenac sodium suppositories to rectal-resected and colostoma-constructed patients, the dose should be increased, because the pharmacokinetics of diclofenac was similar in rabbits and human.     

Drug interactions of diclofenac and its oxidative metabolite with human liver microsomal cytochrome P450 1A2-dependent drug oxidation

Abstract

1.?The purpose of this study was to investigate the inhibitory effects of diclofenac on human cytochrome P450 1A2-, 2C19- and 3A4-mediated drug oxidations and to evaluate the drug interaction potential of diclofenac and 4′-hydroxydiclofenac.

2.?Diclofenac was converted to 4′-hydroxydiclofenac by recombinantly expressed human P450 1A2 with K_m and V_max values of 33?µM and 0.20?min^?1, respectively. Diclofenac and 4′-hydroxydiclofenac suppressed flurbiprofen 4′-hydroxylation by P450 2C9 strongly and moderately, respectively; however, they did not affect P450 2C19-dependent S-mephenytoin hydroxylation or P450 3A4-dependent midazolam hydroxylation.

3.?Although the caffeine 3-N-demethylation activity of liver microsomal P450 1A2 was inhibited by simultaneous incubation with diclofenac, the riluzole N-hydroxylation activities of recombinant P450 1A2 and human liver microsomes were inhibited after preincubation with diclofenac or 4′-hydroxydiclofenac for 20?min in the presence of NADPH. Using the inhibition constant (37?µM) of diclofenac on caffeine 3-N-demethylation and the reported 95th percentiles of maximum plasma concentration (10.5?µM) after an oral dose of diclofenac, the in vivo estimated increase in area under the plasma concentration–time curve was 29%.

4.?These results suggest that diclofenac could inhibit drug clearance to a clinically important degree that depends on P450 1A2. Clinically relevant drug interactions in vivo with diclofenac are likely to be invoked via human P450 1A2 function in addition to those caused by the effect of diclofenac on P450 2C9.     

双氯酚酸钠脂质体的制备及其眼部药代动力学

目的研究双氯酚酸钠脂质体的制备方法并考察其在家兔眼部的药代动力学特征。方法采用逆相蒸发法制备双氯酚酸钠正电荷脂质体。脂质体和滴眼液滴眼后家兔采用高效液相色谱法测定角膜前、角膜和房水中药物浓度。结果制得的脂质体平均粒径为226.5 nm，多分散度为0.214，ζ电位为+18.1 mV，经均匀设计优化处方，包封率可达到63%。0.1%双氯酚酸钠脂质体和滴眼液两种制剂家兔局部滴眼后的药代动力学研究显示，脂质体可延缓药物在角膜前的清除，增加角膜中药物的浓度，药物在房水中半衰期延长，以滴眼液为参比制剂，相对生物利用度为211%。结论双氯酚酸钠正电荷脂质体可以增加药物在角膜前的滞留时间，提高角膜渗透性及药物在眼部的生物利用度，减少滴眼次数。     

Plasma and synovial fluid concentrations of diclofenac sodium and its hydroxylated metabolites during once-daily administration of a 100 mg slow-release formulation

Summary Plasma and knee joint synovial fluid (SF) concentration of diclofenac sodium and its hydroxylated metabolites were measured after chronic dosing with the 100 mg polymer matrix formulation. Peak concentrations were reached in plasma and SF roughly after administration. Plasma concentrations then fell rapidly, but concentrations in SF were maintained for up to 25 h. The active metabolite was present in both fluids throughout the study period. The slow-release form showed a longer plasma/SF equilibration time than the conventional tablet had in a previous study. Prostaglandin E₁ and F_2a concentrations were lower in the early post-dose period but did not correlate with drug concentrations.     

双氯灭痛钠对兔眼损伤性瞳孔缩小的作用

目的:评价0.1%双氯灭痛钠(DFNA)滴眼液和0.1%地塞米松磷酸钠(DeX)滴眼液对兔眼损伤性瞳孔缩小的抑制作用.方法:新西兰白兔6O只,随机分成实验对照组.O.1?NA或0.1?X术前术后用药组及仅术后用药组;手术显微镜下刀片开3mm长角膜,并缝合一针.术前及术后1h分别测角膜直径.结果:兔眼角膜损伤后能导致瞳孔缩小,0.1?NA或0.1?X均能抑制瞳孔缩小,和实验对照组比较,前者有非常显著性差异(P<0.01),后者无差异(P>0.5).结论:0.1?NA滴眼液能抑制兔眼损伤性瞳孔缩小.     

双氯芬酸钠微丸人体内药动学

目的:研究双氯芬酸钠微丸在人体内的药动学。方法:8名健康志愿者单剂量口服双氯芬酸钠微丸。以地西泮为内标,采用RP-HPLC法测定给药后不同时间点双氯芬酸钠的血药浓度。应用3P87程序软件计算药动学参数。结果:双氯芬酸钠浓度在0.02～1.50μg·mL~(-1)范围内线性关系良好(r=0.999 7)。方法回收率为102.3％;日内RSD为2.0％～7.9％,日间RSD为3.1％～11.2％;AUC_(0→∞)为(4.445±1.201)h·μg·mL~(-1);c_(max)为(1.031±0.346)μg·mL~(-1);t_(max)为(2.630±0.520)h。结论:双氯芬酸钠微丸在人体内药动学过程符合一室开放模型,本研究可为双氯芬酸钠微丸的临床应用提供药动学参数。     

Application of Dual Radiotelemetric Technique in Studying Drug–Drug Interaction Between Diclofenac Sodium and Ranitidine HCl in Volunteers

Drug–drug interaction between a commercial diclofenac sodium enteric-coated tablet (Voltaren; V) and a ranitidine HCI tablet (Zantac; Z) was evaluated using a dual radiotelemetric technique according to a randomized three-way Latin-Square crossover design balanced for carryover effects. V and Z were given either alone or in combination (Treatment V, Z, V/Z), with a 14-day washout period between treatments. Eighteen fasted subjects swallowed a tethered Heidelberg pH capsule to provide continuous gastric pH. Then the assigned treatment drug and another Heidelberg pH capsule were given simultaneously. The free pH capsule provided information regarding gastric residence time (GRT). Serial blood samples were obtained for up to 12 hr after dosing and drug levels were determined by validated HPLC methods. Treatment effects on AUC, C _max, T _max, T _lag, T _max–T _lag, and T _1/2 were not significant except C _max, which differed slightly for both V and Z when given in combination as compared to alone. Gastric residence times were 46, 33, and 51 min for Treatments V, Z, and V/Z, respectively. Gastric exposure of the enteric-coated tablet of diclofenac was estimated by pH values obtained from the tethered capsule. Median pH values at 3 and 15 min prior to gastric emptying were 3.8 and 4.9 for the combination treatment versus 2.1 and 2.7 for diclofenac alone. The results of this study indicated that there was minimal drug–drug interaction between diclofenac and ranitidine. The gastric pH range resulting from this study did not influence the oral absorption of enteric-coated diclofenac.     

双氯芬酸钠迟效制剂的药动学

目的 :以双氯芬酸钠普通肠溶片 (R)为对照 ,比较国产双氯芬酸钠迟效制剂 (T)的相对生物利用度和药动学。方法 :采用双交叉、自身对照的方法 ,将 2 4名受试者分为 2组 ,单剂量组分别口服T和R各 10 0mg ;多剂量组 ,每日分别口服T和R各10 0mg ,共 4d。结果 :单剂量组T和R的Cmax,Tmax,T1/2 ,MRT ,AUC0～τ分别为 (115 6±s 36 1)和(3910± 96 8) μg·L- 1,(3.0± 1.0 )和 (2 .3± 0 .5 )h ,(6 .6± 2 .3)和 (2 .9± 1.5 )h ,(12 .3± 2 .3)和 (4.4±1.0 )h ,(92 37± 994 )和 (874 5± 12 16 ) μg·h·L- 1,T的F为 (10 7± 12 ) %。多剂量口服T和R的Cav,FI分别为 (343± 4 6 ) μg·L- 1和 (333± 6 4) μg·L- 1,(2 5 4± 82 ) %和 (40 4± 97) %。结论 :2种制剂口服吸收相似 ,迟效制剂具有峰谷浓度差异小 ,血药浓度波动幅度小等缓释药动学特征。     

Controlled porosity osmotic pump system for the delivery of diclofenac sodium: in-vitro and in-vivo evaluation

Abstract

The objective of this study was to develop controlled porosity osmotic pump (CPOP) tablets of diclofenac sodium (DS). The influence of different cores (polymers and osmogens) and coats (thickness and porosigen content) on DS release were studied. Results revealed that decreasing HPMC viscosity grade from 4000cp (K4M) to 15cp (E15) increased DS release. While increasing the tablet coat thickness decreased DS release. The presence of osmogen increased DS release in the following rank: mannitol?>?lactose?>?avicel. There was a direct relationship between increasing PEG-400 in the coating solution and the amount of drug released in all formulations studied, except in one condition. A comparative bioavailability study using a selected CPOP formulation (T) versus the innovator product (R) revealed that CPOP tablet maintained a less fluctuated DS plasma concentration for up to 24?h with a detected mean C_max of 836.8?±?142.4 and 445.0?±?81.0?ng/mL for R and T, respectively. There were no statistically significant differences between R and T, concerning AUC_0?24 and AUC_0?∞. Moreover, the appearance of the multi-peak phenomenon, which is frequently observed with DS absorption, was found in only 25% of volunteers in case of T versus 75% in case of R.     

双氯芬酸钠缓释片在健康人体的药代动力学和生物等效性

目的:评价双氯芬酸钠缓释片受试制剂和参比制剂在健康人体的药代动力学和生物等效性。方法:24例健康男性志愿者分别行单剂量和多剂量交叉口服双氯芬酸钠缓释片受试与参比制剂,用高效液相色谱-串联质谱法测定血浆中双氯芬酸钠的血药浓度,计算药代动力学参数及相对生物利用度。结果:单剂量口服受试制剂和参比制剂的主要药动学参数如下:Cmax分别为(568.38±271.26)和(458.64±173.96)ng.mL-1,Tmax分别为5(0.5,12)和1.5(0.5,7)h,AUC0～24 h分别为(2 557.72±659.43)和(2 364.14±698.08)ng.h.mL-1,AUC0～∞分别为(2 655.25±635.48)和(2 843.62±808.61)ng.h.mL-1,MRT分别为(6.3±1.8)和(7.0±1.7)h;多剂量口服受试制剂和参比制剂的主要药代动力学参数为:T(ss,max)分别为5(1,7)和4(0.5,8)h,C(ss,max)分别为(520.58±245.89)和(522.98±234.36)ng.mL-1,C(ss,min)分别为(24.96±20.79)和(22.68±17...     

Targeted delivery of diclofenac sodium via gelatin magnetic microspheres formulated for intra-arterial administration

In the present work, we have attempted to deliver diclofenac sodium to a target site by intra-arterial injection of gelatin magnetic microspheres and subsequent localization using an external magnet. Drug-loaded magnetic microspheres were prepared by emulsification/cross-linking method, characterized by drug loading, magnetite content, size distribution, optical microscopy, scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) analysis, differential scanning calorimetry (DSC), X-ray diffraction (XRD), absence of glutaraldehyde by gas chromatography, and in vitro release studies. The targeting efficiency and the therapeutic efficacy of microspheres were studied in vivo in rabbits. The microspheres showed drug loading of 9.1, 18.7, 24.9% w/w, magnetite content of 27.8–28.9% w/w with an average size range of 25–30.6 μm, depending upon the drug–polymer ratio. They were spherical in nature as evidenced by optical microscopy and SEM. FT-IR, DSC, and XRD studies revealed the absence of drug–polymer interaction. Gas chromatography confirmed the absence of residual glutaraldehyde. The microspheres were able to prolong the drug release over 24–30 days and the application of sonication during in vitro release study has slightly increased the release rate. After intra-arterial administration of microspheres, 77.7% of injected dose was recovered at the target site which revealed good targeting efficiency. The microspheres effectively reduced joint swelling, but lesser extent than the oral diclofenac sodium in high dose, in antigen induced arthritic rabbits without producing gastric ulceration which was observed in rabbits treated with oral diclofenac sodium.