Dyloject, a Novel Injectable Diclofenac Formulation, Offers Greater Safety and Efficacy Than Voltarol for Postoperative Dental Pain:

Pharmacokinetics and Safety of a Diclofenac Sodium 75 mg/1 mL Solution (Akis®/Dicloin®) Administered as a Single Intravenous Bolus Injection in Healthy Men and Women

Background

A 1-mL aqueous solution for parenteral injection containing diclofenac sodium and hydroxypropyl-β-cyclodextrin, presently on the market for intramuscular and subcutaneous administration (Akis^®/Dicloin^®), was further developed for intravenous (i.v.) bolus administration.

Objectives

The study objective was to compare the tolerability and diclofenac pharmacokinetics after a single i.v. bolus of the investigational solution to those of other parenteral diclofenac products.

Methods

The study comprised three parts: (i) Part 1: an exploratory dose-escalation study to evaluate the tolerability of 25 mg/1 mL, 50 mg/1 mL and 75 mg/1 mL diclofenac sodium formulations administered as a single 5-s i.v. bolus; (ii) Part 2: an exploratory, randomised, crossover study to evaluate the pharmacokinetics of diclofenac following 5-, 15-, and 30-s i.v. bolus injections of diclofenac sodium 75 mg/1 mL; (iii) Part 3: a randomised crossover study to compare the pharmacokinetics of diclofenac following a 5-s i.v. bolus of the 75 mg/1 mL solution to the pharmacokinetics of diclofenac following a 30-min i.v. infusion or intramuscular administration of a 75 mg/3 mL reference formulation.

Results

The extent of exposure to diclofenac sodium afforded by the 5-s i.v. bolus of 75 mg/1 mL was equivalent to that provided by the 30-min i.v. infusion of 75 mg/3 mL, since the 90% confidence interval of the geometric mean ratio (GMR) of the area under the curve (AUC) from time 0 to the last plasma concentration time t (AUC_0-t) was within the limits 80.00–125.00%, as was the 90% confidence interval of the GMR of the AUC from time 0 extrapolated to infinity (AUC_0-∞). The maximum observed plasma concentration (C_max) was approximately 2.7-fold higher and was achieved earlier (0.05 vs. 0.50 h) with the 1 mL than with the 3 mL formulation, and was similar to data published for a 75 mg/2 mL formulation given as a 15-s i.v. bolus.

Conclusions

Diclofenac sodium 75 mg/1 mL solution administered as a 5-s i.v. bolus was well tolerated. The pharmacokinetic profile, which showed a faster onset and a higher concentration peak than seen for other products and administration routes, suggests a superior analgesic effect.

Pharmacokinetics of Diclofenac and Hydroxypropyl-β-Cyclodextrin (HPβCD) Following Administration of Injectable HPβCD-Diclofenac in Subjects With Mild to Moderate Renal Insufficiency or Mild Hepatic Impairment

Given their established analgesic properties, nonsteroidal anti‐inflammatory drugs (NSAIDs) represent an important postoperative pain management option. This study investigated: (1) the effects of mild or moderate renal insufficiency and mild hepatic impairment on the pharmacokinetics (PK) of diclofenac and hydroxypropyl‐β‐cyclodextrin (HPβCD) following administration of the injectable NSAID HPβCD‐diclofenac; and (2) the PK of HPβCD following administration of HPβCD‐diclofenac and intravenous itraconazole formulated with HPβCD in healthy adults. Diclofenac clearance (CL) and volume of distribution (V_z) tended to increase with decreasing renal function (moderate insufficiency versus mild insufficiency or healthy controls). Regression analysis demonstrated a significant relationship between V_z (but not CL or elimination half‐life, t_½) and renal function. HPβCD CL was significantly decreased in subjects with renal insufficiency, with a corresponding increase in t_½. There were no significant differences in diclofenac or HPβCD PK in subjects with mild hepatic impairment versus healthy subjects. Exposure to HPβCD in healthy subjects following HPβCD‐diclofenac administration was ∼12% of that with intravenous itraconazole, after adjusting for dosing schedule and predicted accumulation (<5% without adjustment). With respect to PK properties, these results suggest that HPβCD‐diclofenac might be administered to patients with mild or moderate renal insufficiency or mild hepatic impairment without dose adjustment (NCT00805090).

A Novel Approach for the Control of Inflammatory Pain: Prostaglandin E2 Complexation by Randomly Methylated β-Cyclodextrins

BACKGROUND

Inhibitors of cyclooxygenase, which block the formation of prostaglandin (PG) E2, are the standard treatment of inflammatory pain. These drugs, however, have serious gastrointestinal, renal, and cardiovascular side effects that limit their clinical use. Cyclodextrins are neutral glucose oligomers that form a hydrophilic outer and a hydrophobic interior cavity used to carry hydrophilic substances. Methyl-β-cyclodextrins are used currently in several drugs as enhancers and also to deliver PGs. We therefore hypothesized that randomly methylated β-cyclodextrins (RAMEB) could be used for pain treatment.

METHODS

An in silico screening for important inflammatory mediators (eg, PGE2, substance P, bradykinin, and calcitonin gene-related peptide) was performed to predict the probability of these molecules binding to RAMEB. Thereafter, a comprehensive in vitro study investigated the complexation affinity of the best target toward RAMEB or its RAMEB-fraction L (FL) using capillary electrophoresis.Wistar rats were injected intraplantarly with complete Freund's adjuvant (CFA) for 96 hours to induce inflammatory hyperalgesia. Subsequently, rats were treated intraplantarly or intravenously either with RAMEB or RAMEB FL and compared with the respective controls. Parecoxib was used as positive control. Mechanical (paw pressure threshold, PPT) and thermal (paw withdrawal latency) nociceptive thresholds were determined before injection and at the indicated time points thereafter. Paw tissue was collected after treatments, and PGE2 and PGD2 contents were measured. Analysis of variance was used for data analysis followed by appropriate post hoc comparisons.

RESULTS

In silico screening indicated that PGE2, with the highest affinity, was the best candidate for RAMEB binding. Likewise, in capillary electrophoresis experiments, RAMEB had a high affinity to form inclusion complexes with the PGE2 (stability constant [K], 360 1/M; 95% confidence interval [C]: 347.58-372.42 M). Local treatment with RAMEB alleviated CFA-induced mechanical (PPT: 76.25 g; 95% CI: 56.24-96.25 g) and thermal hyperalgesia (PPT: 8.50 seconds; 95% CI: 6.76-10.23 seconds). Moreover, a systemic administration of RAMEB decreased CFA-induced mechanical (PPT: 126.66 g; 95% CI: 114.54-138.77 g) and thermal hyperalgesia (paw withdrawal latency: 11.47 seconds; 95% CI: 9.26-13.68 seconds). RAMEB FL resulted in greater in vitro PGE2-binding capacity and decreased PG content as well as hyperalgesia in vivo to a similar extent. Motor activity of the rats was not altered by RAMEB or RAMEB FL.

CONCLUSIONS

Capture of PGs by cyclodextrins could be a novel and innovative tool for the treatment of inflammatory pain and bypassing some unwanted side effects of cyclooxygenase inhibitors.

Efficacy and Safety Profile of Diclofenac/Cyclodextrin and Progesterone/Cyclodextrin Formulations: A Review of the Literature Data

Background

According to health technology assessment, patients deserve the best medicine. The development of drugs associated with solubility enhancers, such as cyclodextrins, represents a measure taken in order to improve the management of patients. Different drugs, such as estradiol, testosterone, dexamethasone, opioids, non-steroidal anti-inflammatories (NSAIDs; i.e. diclofenac), and progesterone are associated with cyclodextrins. Products containing the association of diclofenac/cyclodextrins are available for subcutaneous, intramuscular, and intravenous administration in doses that range from 25 to 75 mg. Medicinal products containing the association of progesterone/cyclodextrins are indicated for intramuscular and subcutaneous injection at a dose equal to 25 mg.

Objectives and Methods

The effects of cyclodextrins have been discussed in the solubility profile and permeability through biological membranes of drug molecules. A literature search was performed in order to give an overview of the pharmacokinetic characteristics, and efficacy and safety profiles of diclofenac/hydroxypropyl-β-cyclodextrin (HPβCD) and progesterone/HPβCD associations.

Results

The results of more than 20 clinical studies were reviewed. It was suggested that the new diclofenac/HPβCD formulation gives a rapid and effective response to acute pain and, furthermore, has pharmacokinetic and efficacy/safety profiles comparable to other medicinal products not containing cyclodextrins. One of the principal aspects of these new diclofenac formulations is that in lowering the dose (lower than 50 mg) the drugs could be more tolerable, especially in patients with comorbid conditions. Moreover, results of studies investigating the characteristics of progesterone and cyclodextrins showed that the new formulation (progesterone/HPβCD 25 mg solution) has the same bioavailability as other products containing progesterone. It is more rapidly absorbed and allows the achievement of peak plasma concentrations in a shorter time. Finally, the new formulation of progesterone was shown to be safe and not inferior to other products already on the market, with the exception of progesterone administered vaginally.

Conclusions

As shown by the results of clinical studies presented in this review, the newly approved medicines containing cyclodextrins have been found to be as effective and as well-tolerated as other medicinal products that do not contain cyclodextrins. Moreover, the newly approved lower dose of diclofenac associated with cyclodextrins is consistent with the European Medicines Agency recommendations reported in the revision of the Assessment Report for Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) and Cardiovascular Risk. Finally, the use of cyclodextrins led to significant increases in solubility and bioavailability of drugs, such as diclofenac and progesterone, and improvement in the efficacy and safety of these drugs.

A Pooled Analysis Evaluating Renal Safety in Placebo- and Active Comparator-Controlled Phase III Trials of Multiple-Dose Injectable HPβCD-Diclofenac in Subjects with Acute Postoperative Pain

OBJECTIVE : While injectable nonsteroidal anti-inflammatory drugs (NSAIDs) are a key component of postoperative multimodal analgesia, renal safety concerns may limit use in some patients. This study examined the renal safety of injectable HPβCD-diclofenac when given for ≤ 5 days following orthopedic or abdominal/pelvic surgery. METHODS : Pooled analysis of data from two randomized, placebo- and active comparator-controlled phase III trials in 608 total patients was conducted. Renal safety was assessed by examining treatment-emergent adverse events (AEs) and postoperative blood urea nitrogen (BUN) and serum creatinine shifts. RESULTS : There were three renal AEs each in the HPβCD-diclofenac (n = 318 patients) and placebo (n = 148 patients) groups, and two renal AEs in the ketorolac group (n = 142 patients). No significant difference in renal AE risk was detected for patients receiving HPβCD-diclofenac (RR: 1.40 [0.15,13.3]; P = 0.75) or ketorolac (RR: 2.08 [0.19,22.7]; P = 0.56) versus placebo. All renal AEs were mild or moderate in severity, and a single renal AE (acute renal failure in a patient receiving HPβCD-diclofenac) was treatment-related. One incidence of postoperative shift to high (> upper limit of normal) serum creatinine occurred in the HPβCD-diclofenac group (n = 2 in the ketorolac group). Mean changes in serum creatinine or BUN did not differ significantly between patients receiving HPβCD-diclofenac and placebo. CONCLUSIONS : While this analysis examined relatively brief exposure typical for parenterally administered analgesics in the postoperative setting in patients with largely normal renal function, the results suggest that HPβCD-diclofenac use for acute postoperative pain may not be associated with added renal safety risks over placebo in this patient population.

Cardiovascular safety of hydroxypropyl-β-cyclodextrin-diclofenac in the management of acute postsurgical pain: a pooled analysis of 2 randomized, double-blind, placebo- and active comparator-controlled phase III clinical trials

STUDY OBJECTIVE

Long-term use of nonsteroidal anti-inflammatory drugs, including selective and nonselective cyclooxygenase inhibitors, has been suggested to be associated with cardiovascular (CV) safety risks. Data are limited regarding CV risks associated with short-term nonsteroidal anti-inflammatory drug use, including injectable formulations, although it has been suggested that even a single dose may increase CV adverse event (AE) risk. The objective of this study was to examine the CV safety of an injectable diclofenac formulation solubilized with hydroxypropyl-β-cyclodextrin (HPβCD) when given for ≤5days postoperatively.

DESIGN

A pooled analysis of CV AEs from 2 pivotal phase III clinical trials examining the efficacy and safety of intravenous (IV) HPβCD-diclofenac vs placebo and the active comparator ketorolac was conducted.

SETTING

Postoperative, with treatment initiated in the postanesthesia care unit ≤6hours postsurgery.

PATIENTS

Overall, 608 abdominal/pelvic and orthopedic surgery patients met inclusion criteria and received ≥1 study medication dose.

INTERVENTIONS

Patients received either HPβCD-diclofenac, ketorolac, or placebo via IV bolus injection every 6hours, for ≤5days postsurgery.

MEASUREMENTS

CV AEs, reported by study investigators, were evaluated through the treatment period and follow-up (≤37days after last study medication dose), and relative CV AE risks were estimated.

MAIN RESULTS

IV HPβCD-diclofenac was not associated with increased treatment-emergent CV AE incidence vs placebo (11.6% vs 12.2%; relative risk, 0.96 [95% confidence interval, 0.56-1.62]). Serious CV AEs as well as treatment-related AEs were uncommon, and there were no reports of myocardial infarction or cerebrovascular accident. CV AEs were uncommon during the follow-up period, occurring in 1.3%, 0%, and 1.4% of patients in the HPβCD-diclofenac, ketorolac, and placebo groups, respectively.

CONCLUSIONS

Although a longer duration follow-up study in a larger patient population would expand our understanding of potential CV risks, the present analysis suggests that postoperative use of HPβCD-diclofenac does not present an added CV safety risk over placebo.

Diclofenac sodium injection (akis(®), dicloin (®)): a review of its use in the management of pain

A novel formulation of diclofenac sodium suitable for subcutaneous or intramuscular injection (Akis(®), Dicloin(®)) has been developed using the complexing agent hydroxypropyl-β-cyclodextrin (HPβCD) as a solubility enhancer. Diclofenac HPβCD is available in several European countries, where it is indicated for use in adults with acute forms of pain, including postoperative pain. Clinical trials have demonstrated the analgesic efficacy of diclofenac HPβCD in terms of relieving moderate to severe postoperative pain in patients undergoing dental surgery or minor orthopaedic surgery. Subcutaneous diclofenac HPβCD also effectively relieved moderate to severe neuropathic pain, related to cancer or not. Diclofenac HPβCD was generally well tolerated in clinical trials, with injection-site reactions among the most commonly reported adverse events. The local tolerability of diclofenac HPβCD was consistently rated as 'good' or 'excellent' across all studies. Subcutaneous administration of diclofenac is a valid alternative to intramuscular delivery, with the advantages of easier administration, the availability of additional body sites suitable for injection and the potential for self-administration. Thus, diclofenac HPβCD 25, 50 or 75 mg/mL solution for subcutaneous or intramuscular injection extends the treatment options available for use in the management of pain in adults.

Advances in NSAID development: evolution of diclofenac products using pharmaceutical technology

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) of the phenylacetic acid class with anti-inflammatory, analgesic, and antipyretic properties. Contrary to the action of many traditional NSAIDs, diclofenac inhibits cyclooxygenase (COX)-2 enzyme with greater potency than it does COX-1. Similar to other NSAIDs, diclofenac is associated with serious dose-dependent gastrointestinal, cardiovascular, and renal adverse effects. Since its introduction in 1973, a number of different diclofenac-containing drug products have been developed with the goal of improving efficacy, tolerability, and patient convenience. Delayed- and extended-release forms of diclofenac sodium were initially developed with the goal of improving the safety profile of diclofenac and providing convenient, once-daily dosing for the treatment of patients with chronic pain. New drug products consisting of diclofenac potassium salt were associated with faster absorption and rapid onset of pain relief. These include diclofenac potassium immediate-release tablets, diclofenac potassium liquid-filled soft gel capsules, and diclofenac potassium powder for oral solution. The advent of topical formulations of diclofenac enabled local treatment of pain and inflammation while minimizing systemic absorption of diclofenac. SoluMatrix diclofenac, consisting of submicron particles of diclofenac free acid and a proprietary combination of excipients, was developed to provide analgesic efficacy at reduced doses associated with lower systemic absorption. This review illustrates how pharmaceutical technology has been used to modify the pharmacokinetic properties of diclofenac, leading to the creation of novel drug products with improved clinical utility.

Single-dose and multiple-dose pharmacokinetics and dose proportionality of intravenous and intramuscular HPβCD-diclofenac (Dyloject) compared with other diclofenac formulations

STUDY OBJECTIVE

To evaluate single- and repeated-dose pharmacokinetics (PK) and dose proportionality of hydroxypropyl-β-cyclodextrin (HPβCD)-diclofenac compared with Voltarol after intravenous (IV) and intramuscular (IM) administration.

DESIGN

Study 1: Single-dose randomized four-way crossover study. Study 2: Multiple-dose randomized three-way crossover study.

SETTING

Clinical research center.

SUBJECTS

Healthy adult volunteers.

INTERVENTION

Study 1: Subjects received HPβCD-diclofenac and Voltarol, IV and IM, with a 5-day washout between treatment periods. Study 2: Subjects received two doses of IV HPβCD-diclofenac and oral Cataflam once every 6 hours for four doses with a 48-hour washout period between treatment periods.

MEASUREMENTS AND MAIN RESULTS

Study 1: IV HPβCD-diclofenac had a higher peak plasma concentration (Cmax ) and earlier time to reach maximum plasma concentration (Tmax ), but equivalent plasma exposure (area under the curve from time zero to t [AUC0-t ]) to IV Voltarol. The geometric mean ratio of HPβCD-diclofenac (IV) to Voltarol (IV) for AUC0-t was 106.27%. The geometric mean ratio of HPβCD-diclofenac (IM) to Voltarol (IM) for AUC0-t was 110.91%. The geometric mean ratio of HPβCD-diclofenac (IV) to HPβCD-diclofenac (IM) for AUC0-t was 101.25%. The geometric mean ratio of HPβCD-diclofenac (IM) to Voltarol (IV) for AUC0-t was 104.96%. Study 2: Cmax for diclofenac was 2904 and 6031 ng/ml after the first IV dose of 18.75 and 37.5 mg HPβCD-diclofenac, respectively, and was 3090 and 5617 ng/ml after the fourth dose, indicating no accumulation. Plasma exposures to 18.75 mg (866 ng·hour/ml) and 37.5 mg (1843 ng·hour/ml) IV HPβCD-diclofenac bracketed that of oral Cataflam 50 mg (1473 ng·hour/ml).

CONCLUSIONS

Study 1: Bioavailability in terms of AUC after IV administration was equivalent for HPβCD-diclofenac compared with Voltarol and after IM administration of HPβCD-diclofenac and Voltarol. Bioavailability in terms of AUC after IM administration of HPβCD-diclofenac was equivalent to IV administration of HPβCD-diclofenac and IV administration of Voltarol. Study 2: HPβCD-diclofenac showed dose proportionality after single- and multiple-dose administration and no accumulation of HPβCD-diclofenac. HPβCD-diclofenac was safe and well tolerated following IV and IM administration.

Efficacy and safety of low dose subcutaneous diclofenac in the management of acute pain: a randomized double-blind trial

OBJECTIVE

Diclofenac is an effective and well-tolerated nonsteroidal anti-inflammatory drug (NSAID) frequently used in the treatment of acute pain. Marketed formulations for parenteral administration usually contain 75 mg/3 mL of diclofenac sodium, which provide limited dosing flexibility, and are usually given intramuscularly.

METHODS

We present a randomized, double-blind, active comparator- and placebo-controlled, parallel-group phase III multicenter study, investigating efficacy and tolerability of a new 1 mL-volume formulation of diclofenac sodium (25, 50 or 75 mg) containing hydroxypropyl-β-cyclodextrin (HPβCD) as a solubility enhancer. This low-volume formulation allows subcutaneous (SC), in addition to intramuscular (IM) administration. Patients developing moderate-to-severe pain (≥ 50 mm on Visual Analogue Scale) after third molar extraction under local anesthesia were randomized to one of the 4 SC injections: 25 mg diclofenac HPβCD (n = 77), 50 mg diclofenac HPβCD (n = 76), 75 mg diclofenac HPβCD (n = 78), or placebo (n = 75).

RESULTS

Mean pain intensity difference at 1.5 hours postdose (primary endpoint) was higher in all diclofenac-treated groups than placebo group. The adjusted means (95% CI) were 36.5 (31.7 to 41.2) in diclofenac 25 mg group, 37.3 (32.6 to 42.1) in diclofenac 50 mg group, 37.7 (33.0 to 42.4) in diclofenac 75 mg group, and 12.3 (7.44 to 17.1) in placebo group. Both 25 and 50 mg doses of diclofenac produced significantly greater pain relief than placebo (P < 0.001 in both comparisons).

CONCLUSION

Single SC doses of diclofenac HPβCD of 25 and 50 mg are effective and well tolerated for relieving pain compared with placebo.

Safety of a novel parenteral formulation of diclofenac after major orthopedic or abdominal/pelvic surgery in a population including anticoagulated, elderly or renally insufficient patients: an open-label, multiday, repeated dose clinical trial

OBJECTIVE

Decisions to use or avoid nonsteroidal anti-inflammatory drugs (NSAIDs) for postsurgical pain are often influenced by concerns about bleeding and renal adverse effects. The objective of this study was to evaluate the safety of a novel parenteral NSAID, hydroxypropyl-β-cyclodextrin (HPβCD) diclofenac, in a large postsurgical patient population, with particular focus on bleeding and renal effects.

METHODS

This was a large open-label study in adult patients with acute moderate-to-severe pain following major surgery. Patients received ≥2 days of continuous treatment with HPβCD diclofenac, administered as a small-volume bolus injection every 6 hours. Few exclusion criteria were applied in order to reflect surgical patient populations commonly managed in clinical practice. Adverse events (AEs) were recorded throughout the study. The incidences of bleeding- and renal-related AEs were examined in patient subpopulations with known risk factors for NSAID-induced complications: advanced age, pre-existing renal insufficiency, concomitant anticoagulant use, prolonged exposure, elevated dosage, and major surgeries.

RESULTS

Of the total 971 patients studied, 38% were ≥65 years old (12% >75 years), 62% received concomitant anticoagulants, and 6% had pre-existing renal insufficiency. HPβCD diclofenac was well tolerated by the patient population. AE rates are presented by risk factor to enable clinicians to better describe renal- or bleeding-related AEs.

CONCLUSIONS

In addition to its previously demonstrated efficacy, this study provides evidence of HPβCD diclofenac's safety in a large postsurgical population including anticoagulated, elderly or renally insufficient patients. Because study exclusion criteria were minimal, these findings may be broadly generalizable to populations commonly treated in clinical practice.

Effects of injectable HPβCD-diclofenac on the human delayed rectifier potassium channel current in vitro and on proarrhythmic QTc in vivo

BACKGROUND

Novel formulations and administration routes of established drugs may result in higher maximum concentrations or total exposures and potentially cause previously unrecognized adverse events.

OBJECTIVE

This study evaluated the proarrhythmic potential of hydroxypropyl-β-cyclodextrin (HPβCD)-diclofenac, a novel injectable diclofenac formulation solubilized with hydroxypropyl-β-cyclodextrin (HPβCD), on ventricular electrical conduction in preclinical and clinical models.

METHODS

We assessed the effects of diclofenac, HPβCD, and HPβCD-diclofenac on the human delayed rectifier potassium channel (IKr) using human embryonic kidney (HEK) 293 cells transfected with a human ether-à-go-go-related gene (hERG) using whole-cell patch-clamp. In a single-dose, active- and placebo-controlled, 4-period crossover, thorough QT in vivo study, 70 healthy volunteers (mean age, 23.3 years; range, 18-49 years; 55.75% male) received HPβCD-diclofenac at 37.5- and 75-mg doses, inactive vehicle (placebo), and an active control (moxifloxacin).

RESULTS

In vitro, diclofenac produced no statistically significant effect on IKr. Significant, non-dose-dependent effects were observed in the presence of HPβCD or HPβCD-diclofenac of similar magnitude across the 300-fold dose range of concentrations tested, suggesting an artifact due to the detergent effect of HPβCD in this in vitro model. In vivo, neither HPβCD-diclofenac dose resulted in QTc prolongation ≥2 ms (≥5 ms is the threshold of clinical concern). No correlation was evident between changes in QTc and plasma concentrations of diclofenac or HPβCD. Confirming study sensitivity, moxifloxacin produced a mean QTc prolongation >10 ms.

CONCLUSIONS

The findings from the present study suggest that HPβCD-diclofenac does not have a dose-dependent effect in the in vitro hERG assay system and does not produce proarrhythmic QTc prolongation in vivo. ClinicalTrials.gov identifier: NCT01812538.

Long-term parenteral administration of 2-hydroxypropyl-β-cyclodextrin causes bone loss

Cyclodextrins are oligosaccharides which are used in the pharmaceutical industry and research as vehicles for application of apolar substances such as steroids. The aim of this study was to examine the long-term effects of parenteral administration of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) on bone. Sham-operated (SHAM) or ovariectomized (OVX) adult rats were subcutaneously injected with physiological saline, 50, or 200 mg/kg HP-β-CD daily. After 4 months, body weight in OVX rats and uterine weight in SHAM rats were significantly lower after administration of 200 mg/kg HP-β-CD, relative to vehicle controls. At 200 mg/kg, HP-β-CD was hepatotoxic as measured by increased serum transaminases, and reduced serum albumin. Moreover, 200 mg/kg HP-β-CD led to decreased vertebral and tibial bone mineral density (BMD), and to cortical thinning at the tibial shaft. Bone loss in HP-β-CD-treated rats was associated with increased bone resorption as measured by increased renal deoxypyridinoline excretion. Although 50 mg/kg HP-β-CD was devoid of overt signs of organ toxicity and did not impair BMD, bone resorption was already increased. In summary, subcutaneous long-term administration of HP-β-CD at a daily dose of 200 mg/kg led to increased bone resorption and subsequent bone loss. Minor alterations in bone metabolism were also seen at 50 mg/kg.

A double-blind placebo-controlled comparison of a novel formulation of intravenous diclofenac and ketorolac for postoperative third molar extraction pain

Dyloject is a novel formulation of diclofenac intended for intravenous (IV) administration. This formulation employs the solubilizing agent hydroxypropyl-β-cyclodextrin to permit bolus IV administration. The efficacy and safety of 5 dose levels of IV diclofenac were compared with IV ketorolac and placebo following third molar extraction. This was a single-dose, randomized, double-blind, placebo- and comparator-controlled, parallel-group study. A total of 353 subjects with moderate to severe pain received placebo; ketorolac 30 mg; or IV diclofenac 3.75, 9.4, 18.75, 37.5, or 75 mg (N  =  51 for all groups, except N  =  47 for ketorolac). The primary endpoint was total pain relief over 6 hours (TOTPAR6) as measured by the visual analog scale (VAS). Secondary endpoints included multiple measures of pain intensity and relief; patient global evaluation; and times to pain relief and rescue medication. Dropouts and adverse effects (AEs) were also monitored. IV diclofenac was superior to placebo as measured by TOTPAR6 (P < .0001 for all doses except 3.75 mg, for which P  =  .0341). IV diclofenac 3.75 mg was statistically superior to placebo for TOTPAR2 and TOTPAR4. IV diclofenac at both 37.5 and 75 mg was superior to placebo (P < .05) at the earliest (5 minute) assessments of pain intensity and pain relief, but ketorolac was not. The proportion of patients reporting 30% or greater pain relief at 5 minutes was significantly greater after IV diclofenac 37.5 and 75 mg than after ketorolac 30 mg or placebo. Secondary endpoints confirmed the primary findings. Treatment-related AEs were generally mild to moderate and were typical for nonsteroidal anti-inflammatory drugs (NSAIDs). The more rapid onset of action of IV diclofenac compared with the reference injectable NSAID ketorolac suggests additional clinical benefit. If confirmed in larger series, these findings may improve the safety and efficacy of postoperative NSAID analgesia.