Single-dose pharmacokinetics of fentanyl buccal soluble film

Effectiveness of fentanyl buccal soluble film in cancer patients with inadequate breakthrough pain control

BACKGROUND

Clinical evidence for the rapidity and effectiveness of fentanyl buccal soluble film (FBSF) in reducing pain intensity of breakthrough cancer pain (BTcP) remains inadequate. This study aimed to evaluate the efficacy of FBSF proportional to the around-the-clock (ATC) opioid regimens in rapidly relieving the intensity of BTcP episodes by determining the percentage of patients requiring further dose titration.

METHODS

The study procedure included a dose-finding period followed by a 14-day observation period. Pain intensity was recorded with a Numeric Rating Scale (NRS) at onset and 5, 10, 15, and 30 min after FBSF self-administration. Meaningful pain relief was defined as the final NRS score ≤ 3. Satisfaction survey was conducted for each patient after treatment using the Global Satisfaction Scale.

RESULTS

A total of 63 BTcP episodes occurred in 30 cancer patients. Only one patient required rescue medication at first BTcP episode and then achieved meaningful pain relief after titrating FBSF by 200 µg. Most BTcP episodes relieved within 10 min. Of 63 BTcP episodes, 30 (47.6%), 46 (73.0%), and 53 (84.1%) relieved within 5, 10, and 15 min after FBSF administration. Only grade 1/2 adverse events were reported, including somnolence, malaise, and dizziness. Of the 63 BTcP episodes, 82.6% were rated as excellent/good satisfaction with FBSF.

CONCLUSION

FBSF can be administrated "on demand" by cancer patients at the onset of BTcP, providing rapid analgesia by achieving meaningful pain relief within 10 min.

TRIAL REGISTRATION

This study was retrospectively registered 24 December, 2021 at Clinicaltrial.gov (NCT05209906): https://clinicaltrials.gov/study/NCT05209906 .

Nalmefene Hydrochloride: Potential Implications for Treating Alcohol and Opioid Use Disorder

Nalmefene hydrochloride was first discovered as an opioid antagonist derivative of naltrexone in 1975. It is among the most potent opioid antagonists currently on the market and is differentiated from naloxone and naltrexone by its partial agonist activity at the kappa-opioid receptor which may benefit in the treatment of alcohol use disorder. Oral nalmefene has been approved in the European Union for treatment of alcohol use disorder since 2013. As of 2023, nalmefene is available in the United States as an intranasal spray for reversal of opioid overdose but is not approved for alcohol or opioid use disorder as a maintenance treatment. The substantially longer half-life of nalmefene and 5-fold higher binding affinity to opioid receptors makes it a superior agent over naloxone in the reversal of high potency synthetic opioids like fentanyl and the emerging nitazenes. Nalmefene presents with a comparable side effect profile to other opioid antagonists and should be considered for further development as a maintenance treatment for opioid and other substance use disorders.

Mucosal Vaccine Delivery Using Mucoadhesive Polymer Particulate Systems

Vaccination has been recently attracted as one of the most successful medical treatments of the prevalence of many infectious diseases. Mucosal vaccination has been interested in many researchers because mucosal immune responses play part in the first line of defense against pathogens. However, mucosal vaccination should find out an efficient antigen delivery system because the antigen should be protected from degradation and clearance, it should be targeted to mucosal sites, and it should stimulate mucosal and systemic immunity. Accordingly, mucoadhesive polymeric particles among the polymeric particles have gained much attention because they can protect the antigen from degradation, prolong the residence time of the antigen at the target site, and control the release of the loaded vaccine, and results in induction of mucosal and systemic immune responses. In this review, we discuss advances in the development of several kinds of mucoadhesive polymeric particles for mucosal vaccine delivery.

Transmucosal drug administration as an alternative route in palliative and end-of-life care during the COVID-19 pandemic

The Coronavirus disease 2019 (COVID-19) pandemic has led to a surge in need for alternative routes of administration of drugs for end of life and palliative care, particularly in community settings. Transmucosal routes include intranasal, buccal, sublingual and rectal. They are non-invasive routes for systemic drug delivery with the possibility of self-administration, or administration by family caregivers. In addition, their ability to offer rapid onset of action with reduced first-pass metabolism make them suitable for use in palliative and end-of-life care to provide fast relief of symptoms. This is particularly important in COVID-19, as patients can deteriorate rapidly. Despite the advantages, these routes of administration face challenges including a relatively small surface area for effective drug absorption, small volume of fluid for drug dissolution and the presence of a mucus barrier, thereby limiting the number of drugs that are suitable to be delivered through the transmucosal route. In this review, the merits, challenges and limitations of each of these transmucosal routes are discussed. The goals are to provide insights into using transmucosal drug delivery to bring about the best possible symptom management for patients at the end of life, and to inspire scientists to develop new delivery systems to provide effective symptom management for this group of patients.

A dose titration study of fentanyl buccal soluble film for breakthrough cancer pain in Taiwan

BACKGROUND

Fentanyl buccal soluble film (FBSF), a new formulation of fentanyl, is developed for the treatment of breakthrough pain (BTP) in opioid-tolerant patients with cancer.

AIMS

This study aimed to assess the feasible dose range of FBSF required for Taiwanese population.

METHODS AND RESULTS

This was an open-label, multicenter, noncomparative study. Cancer patients who were aged 20 years or older and had a stable regimen equivalent to 60 to 1000 mg/day of oral morphine, 20 to 120 mg/day of intravenous morphine, or 25 to 300 μg/h of transdermal fentanyl for at least 1 week were enrolled. The primary endpoint was the feasible dose range of FBSF. Secondary endpoints included difference in pain intensity at 30 minutes (PID30), percentage of episodes requiring rescue medication, and overall satisfaction. Adverse events (AEs) and serious AEs (SAEs) were recorded for safety measurements. The final effective dose in the per-protocol (PP) population (n = 30) ranged from 200 to 800 μg, of which 26 subjects (86.7%) achieved an effective dose range of 200 to 400 μg. Among the 283 BTP episodes recorded in the maintenance period, the mean PID30 was 4.0, and only 13 events (4.6%) required rescue medication. For 63.6% of the BTP episodes, patients rated their satisfaction as good to excellent. Only 5% of AEs were considered drug-related.

CONCLUSIONS

Individualized dose titration is recommended for BTP management for patients' benefit. Overall, FBSF was effective and well tolerated and was positively correlated with patients' background opioid dose for persistent pain management.

Effect of Modulated Electrohyperthermia on the Pharmacokinetics of Oral Transmucosal Fentanyl Citrate in Healthy Volunteers

PURPOSE

This study aimed to determine whether changes occur in fentanyl absorption and disposition when administered in conjunction with modulated electrohyperthermia (mEHT) treatment.

METHODS

A randomized, single-dose, crossover, open-label study was used to investigate the effect of mEHT on the pharmacokinetic properties of fentanyl in 12 healthy volunteers. The 12 healthy volunteers were each administered a single dose of oral transmucosal fentanyl citrate (OTFC) or a single dose of OTFC with mEHT. mEHT was performed on the abdomen for 1 hour. Blood samples were collected for 24 hours after dosing. The temperature of the abdominal skin surface was assessed before dosing and at 10, 20, and 60 minutes after dosing.

FINDINGS

Geometric mean ratios (ratio of fentanyl with mEHT to fentanyl alone) for the C_max and AUC_0-last were 1.20 (90% CI, 1.09-1.32) and 1.15 (90% CI, 0.99-1.33), respectively. The mean temperature of the abdominal skin surface increased by approximately 4°C.

IMPLICATIONS

There was an increase in the overall exposure to the drug without implications of any clinical significance. OTFC can be administered without limitations in combination with mEHT, and it is not necessary to modify the dosing regimen. cris.nih.go,kr Identifier: KCT0001286.

Transmucosal Immediate-Release Fentanyl for Breakthrough Cancer Pain: Opportunities and Challenges for Use in Palliative Care

Opioids are used to treat breakthrough cancer pain (BTCP) and can be classified by relative duration and onset of action. Regulatory approvals of numerous transmucosal immediate-release fentanyl (TIRF) formulations provide alternative options to palliative care-trained providers in the management of BTCP. TIRFs have been formulated as a sublingual tablet, sublingual spray, intranasal spray, pectin-based nasal spray, buccal tablet, and buccal soluble film. Differences exist between TIRFs regarding formulation design and dosing to treat BTCP. Opportunities for use include palliation of BTCP in head and neck cancer and/or radiation-induced mucositis. The purpose of this review is to discuss TIRF formulation and dosing, pharmacokinetics, clinical efficacy, patient acceptability, and safety/tolerability. In addition, barriers to TIRF utilization will be discussed.

Single-dose pharmacokinetics of fentanyl sublingual spray and oral transmucosal fentanyl citrate in healthy volunteers: a randomized crossover study

BACKGROUND

Fentanyl sublingual spray (FSS) is a novel fentanyl formulation recently developed for the treatment of breakthrough cancer pain, which is characterized by a fast onset and a relatively short duration.

OBJECTIVE

To compare rate of absorption and systemic bioavailability between FSS and oral transmucosal fentanyl citrate (OTFC) in healthy volunteers.

METHODS

This randomized 3-way crossover study involved 29 healthy volunteers (25 men and 4 women; mean age, 35 years) who received single doses of FSS (400 μg), OTFC (400 μg), and intravenous fentanyl citrate (100 μg) separated by washout periods of ≥7 days. Oral naltrexone was given to minimize potential adverse effects of fentanyl. Plasma fentanyl concentrations were measured for 36 hours after each dose for the calculation of pharmacokinetic parameters.

RESULTS

Mean Cmax values of fentanyl were higher with FSS versus OTFC (0.81 ng/mL vs 0.61 ng/mL) and were attained more quickly; the median Tmax was 1.5 hours with FSS and 2.0 hours with OTFC (P < 0.05). Furthermore, potentially effective fentanyl concentrations were achieved more quickly with FSS than with OTFC. Five and 10 minutes after administration, mean plasma concentrations were 19.0% and 53.7% of Cmax with FSS, respectively, compared with levels below the lower limit of assay quantification and 6.1%, respectively, with OTFC. Plasma concentrations of fentanyl at 10 minutes with FSS were equivalent to those with OTFC at 60 minutes. The Cmax and AUCs were approximately 33% to 36% greater with FSS than with OTFC, and the 90% CIs of the geometric mean ratios for each parameter fell outside the bioequivalence range of 80% to 125%. Systemic bioavailability was also greater with FSS than with OTFC (approximately 76% vs 51%). All 3 fentanyl treatments were well tolerated. All reported adverse events were mild and consistent with those previously reported in healthy volunteers receiving transmucosal fentanyl with naltrexone, and none occurred in >2 participants during any treatment period.

CONCLUSIONS

Absorption of fentanyl in this study was faster and bioavailability was greater with FSS than with OTFC. The pharmacokinetic profile of the sublingual spray closely matches the duration of onset to pain intensity in a breakthrough cancer pain episode. These findings suggest that FSS is appropriate for the treatment of breakthrough cancer pain. ClinicalTrials.gov identifier: NCT01780233.

Pharmacokinetics of non-intravenous formulations of fentanyl

Fentanyl was structurally designed by Paul Janssen in the early 1960s as a potent opioid analgesic (100-fold more potent than morphine). It is a full agonist at μ-opioid receptors and possesses physicochemical properties, in particular a high lipophilicity (octanol:water partition coefficient >700), which allow it to cross quickly between plasma and central nervous target sites (transfer half-life of 4.7-6.6 min). It undergoes first-pass metabolism via cytochrome P450 3A (bioavailability ~30 % after rapid swallowing), which can be circumvented by non-intravenous formulations (bioavailability 50-90 % for oral transmucosal or intranasal formulations). Non-intravenous preparations deliver fentanyl orally-transmucosally, intranasally or transdermally. Passive transdermal patches release fentanyl at a constant zero-order rate for 2-3 days, making them suitable for chronic pain management, as are iontophoretic transdermal systems. Oral transmucosal and intranasal routes provide fast delivery (time to reach maximum fentanyl plasma concentrations 20 min [range 20-180 min] and 12 min [range 12-21 min], respectively) suitable for rapid onset of analgesia in acute pain conditions with time to onset of analgesia of 5 or 2 min, respectively. Intranasal formulations partly bypass the blood-brain barrier and deliver a fraction of the dose directly to relevant brain target sites, providing ultra-fast analgesia for breakthrough pain. Thanks to the development of non-intravenous pharmaceutical formulations, fentanyl has become one of the most successful opioid analgesics, and can be regarded as an example of a successful reformulation strategy of an existing drug based on pharmacokinetic research and pharmaceutical technology. This development broadened the indications for fentanyl beyond the initial restriction to intra- or perioperative clinical uses. The clinical utility of fentanyl could be expanded further by more comprehensive mathematical characterizations of its parametric pharmacokinetic input functions as a basis for the rational selection of fentanyl formulations for individualized pain therapy.

In vitro and in vivo evaluation of a sublingual fentanyl wafer formulation

Background

The objective of this study was to prepare a novel fentanyl wafer formulation by a freeze-drying method, and to evaluate its in vitro and in vivo release characteristics, including its bioavailability via the sublingual route.

Methods

The wafer formulation was prepared by freeze-drying an aqueous dispersion of fentanyl containing sodium carboxymethylcellulose and amylogum as matrix formers. Uniformity of weight, friability, and dissolution testing of the fentanyl wafer was achieved using standard methods, and the residual moisture content was measured. The fentanyl wafer was also examined using scanning electron microscopy and x-ray diffraction. The absolute bioavailability of the fentanyl wafer was evaluated in 11 opioid-naïve adult female patients using a randomized crossover design.

Results

In vitro release showed that almost 90% of the fentanyl dissolved in one minute. In vivo, the first detectable plasma fentanyl concentration was observed after 3.5 minutes and the peak plasma concentration between 61.5 and 67 minutes. The median absolute bioavailability was 53.0%.

Conclusion

These results indicate that this wafer has potential as an alternative sublingual fentanyl formulation.

Fentanyl for the treatment of tumor-related breakthrough pain

BACKGROUND

Breakthrough cancer pain (BTCP) is common among cancer patients and markedly lowers their quality of life. The treatment for BTCP episodes that is recommended in current guidelines involves extended-release formulations in combination with rapid-onset and short-acting opioids. In the past few years, several new preparations of fentanyl, an opioid with a very rapid onset, have been approved for this indication. Treating physicians need to be aware of the clinical differences between the newer fentanyl preparations and immediate-release opioids.

METHODS

We searched the PubMed and Embase databases for randomized controlled trials (RCTs) of fentanyl for buccal, sublingual or intranasal administration in comparison with other opioids or a different fentanyl preparation for the treatment of BTCP.

RESULTS

In 6 trials of buccal, sublingual or intranasal fentanyl versus oral immediate-release opioids for the treatment of BTCP episodes, the use of fentanyl was associated with significantly less intense pain. In particular, fentanyl more often lowered the intensity of pain by at least 33% (range between studies: 13% to 57%) or by at least 50% (range between studies: 9% to 38%) within 15 minutes. Please change to "versus" if you agree.] Dose titration should begin at the lowest dose. When one fentanyl preparation is exchanged for another, the effective dose will probably differ.

CONCLUSION

The newer fentanyl preparations extend the treatment options for BTCP. They relieve pain within a short time better than conventional, immediate-release oral opioids do and may therefore be very helpful for patients with suddenly arising, intense, and short-lasting BTCP episodes. Further comparative trials are urgently needed.

Considerations in selecting rapid-onset opioids for the management of breakthrough pain

Breakthrough pain (BTP) is a transitory pain that occurs despite the use of long-term, around-the-clock analgesia. It is highly prevalent in certain populations and places a significant burden on patients, their families, caregivers, and health-care systems. Despite its prevalence and impact, BTP is sometimes unrecognized and often undertreated. Various formulations of fentanyl – a rapid-onset opioid with short duration of action – are available for the management of BTP. The efficacy of formulations using transmucosal, transbuccal, sublingual, and intranasal administration routes has been demonstrated for BTP treatment in clinical trials. However, a lack of head-to-head trials evaluating their relative efficacy makes it challenging for physicians to reach informed decisions on the most efficacious intervention for individual patients. In the absence of clear data on the relative efficacy of fentanyl formulations, prescribing decisions need to be based on physician understanding and experience and product cost and availability, taking into account the individual patient’s needs, the ability of the patient or caregivers to administer medication, and the patient’s wishes. This review evaluates current pharmacologic methods of alleviating BTP and discusses factors that should be considered when selecting the most appropriate formulation for individual patients. With the range of fentanyl formulations available, it is now possible to successfully address BTP in the majority of patients.

A review of the pharmacokinetic profile of transmucosal fentanyl formulations

BACKGROUND AND OBJECTIVES

Breakthrough pain (BTP) is a transitory flare of moderate-to-severe pain that occurs in patients with stable, controlled persistent pain. Management of BTP episodes is difficult because frequency, time-to-peak intensity, and duration of episodes vary both within and between individuals. Formulations of fentanyl that use a buccal, sublingual, or nasal transmucosal route of administration have been developed for the treatment of BTP in opioid-tolerant patients with cancer. These formulations allow rapid passage into the bloodstream and avoid first-pass metabolism and, therefore, are more likely to match the time-course of BTP episodes than are oral formulations. The purposes of this analysis were to identify and review published data describing the pharmacokinetic properties of rapid-onset fentanyl formulations and to evaluate these properties in view of the temporal dynamic characteristics of BTP in order to help guide medical practice.

METHODS

Relevant publications were searched in the PubMed database from 1998. The plasma drug concentration-time profile of each formulation obtained from the identified studies was adjusted to a consistent scale for comparison.

RESULTS

The data revealed that the various transmucosal formulations resulted in three typical plasma fentanyl concentration profiles: (1) type 1: a very rapid rise and short duration; (2) type 2: a rapid increase and sustained intensity; and (3) type 3: a slower onset and longer duration.

CONCLUSIONS

Given the substantial variability of BTP episodes experienced by patients, these pharmacokinetic differences may provide useful information for a physician who is selecting a rapid-onset opioid medication for a patient.

Fentanyl (transmucosal)

Therapeutic Reviews aim to provide essential independent information for health professionals about drugs used in palliative and hospice care. Additional content is available on www.palliativedrugs.com. Country-specific books (Hospice and Palliative Care Formulary USA, and Palliative Care Formulary, British and Canadian editions) are also available and can be ordered from www.palliativedrugs.com. The series editors welcome feedback on the articles (hq@palliativedrugs.com).

A comprehensive review of rapid-onset opioids for breakthrough pain

Breakthrough pain (BTP) is a transitory pain (reaching maximum severity in ~15 minutes and lasting ~60 minutes in patients with cancer) that occurs despite the management of chronic pain with long-term around-the-clock analgesia. BTP occurs in 33-65% of patients with chronic cancer pain and in ~70% of patients with chronic noncancer pain. BTP has historically been managed with short-acting opioids; however, these medications have a pharmacokinetic profile that does not correlate with the sudden onset and short time to maximum severity of BTP. Interest in rapid-onset opioids to relieve BTP has therefore been growing. This comprehensive review aims to summarize the currently available clinical data for the approved rapid-onset opioids, which comprise different formulations of fentanyl, a μ-opioid receptor agonist with anaesthetic and analgesic properties. Administration routes for fentanyl in the management of BTP currently include the transmucosal and intranasal routes; an intrapulmonary formulation is also in development. The findings of this review suggest that the efficacy and safety of the approved rapid-onset opioids are comparable.

A phase I pharmacokinetic and bioavailability study of a sublingual fentanyl wafer in healthy volunteers

BACKGROUND

The sublingual administration of opioids is a simple and noninvasive method that provides rapid analgesia. In this phase I study we investigated the pharmacokinetics and bioavailability of a fentanyl wafer in healthy volunteers. The principal study objective was to investigate the pharmacokinetic profile of a new sublingual fentanyl wafer and to establish its absolute bioavailability.

METHODS

Twenty-four healthy volunteers, mean age 23 years, were randomly assigned to receive the equivalent of fentanyl 100 μg by both the sublingual and IV routes. Blood samples were collected in sterile polypropylene tubes for 24 hours after each fentanyl administration. The pharmacokinetic parameters were determined by model-independent pharmacokinetic analyses of the plasma fentanyl concentration-time profiles.

RESULTS

The mean absolute bioavailability of the sublingual fentanyl wafer was 78.9% (90% confidence interval [CI] 51.1% to 121.7%). The first detectable plasma fentanyl concentration time ranged from 2 to 10 minutes in all volunteers, and the mean (±SD) time to peak plasma concentration at 0.91 (±0.73) hours after administration.

CONCLUSION

Sublingual administration of fentanyl as a wafer product resulted in rapidly detectable plasma fentanyl concentrations. The absolute bioavailability of 78.9% indicated a high systemic availability of fentanyl and suggests that further development of this wafer is justified.

A review of transbuccal fentanyl use in the emergency department

Patients with severe, painful injuries and illnesses treated in the emergency department are commonly administered opioid medications. Intravenous administration provides the most rapid onset of pain relief and is readily titrated. Fentanyl, administered intravenously, is well documented as an effective medication for pain management in the emergency department. It is preferred in many settings due to its minimal hemodynamic effects, as compared to other commonly used opioids. However, not all patients require intravenous access. These patients are given orally administered pain medications. The oral route is effective at minimizing pain but has a much slower onset of action when compared to the intravenous route. As an alternative to the slower onset of action seen with oral opioids, this paper discusses the use of fentanyl buccal tablet for pain management in the emergency department. Fentanyl buccal tablets are readily absorbed, with a bioavailability of approximately 65%, and have a more rapid onset of action than achieved with traditional oral opioids used in the emergency department.

Fentanyl for breakthrough pain: a systematic review

The purpose of this article is to systematically review the use of fentanyl as an analgesic for breakthrough pain. This article found that the oral transmucosal fentanyl (OTFC) had a quicker onset to analgesia than oral immediate-release opioids. Intranasal fentanyl (INFS) had a quicker onset to analgesia than buccal tablets, which in turn had a quicker onset to analgesia than OTFC. Patient acceptance and global rating of efficacy were greater for INFS than for buccal fentanyl. OTFC and INFS have been used effectively to reduce acute pain in children who are opioid-naive. Abuse and addiction to OTFC, fentanyl buccal tablets and INFS was low, owing to patient selection.

Absorption and tolerability of fentanyl buccal soluble film (FBSF) in patients with cancer in the presence of oral mucositis

PURPOSE

Fentanyl buccal soluble film (FBSF) consists of a small, bilayered, water-soluble polymer film that adheres to the buccal mucosa and rapidly delivers fentanyl into the systemic circulation. The purpose of this study was to evaluate the absorption of fentanyl from FBSF in patients with cancer, with and without grade 1 oral mucositis, and to assess the tolerability of FBSF in this patient population.

PATIENTS AND METHODS

In an open-label, single-dose study, two groups of opioid-naive patients (ie, not receiving opioids on a regular basis) with cancer received a 200 μg dose of FBSF. Patients in cohort I (n = 7) had grade 1 mucositis, and patients in cohort II (n = 7) were age- and gender-matched controls without mucositis. The FBSF dose was placed on the area of mucositis in cohort I and on a matching location in cohort II. Blood samples were collected up to 4 hours after administration, and safety assessments were made throughout the study.

RESULTS

Peak plasma concentration and area under the concentration-time curve from time 0 to 4 hours post-dose values of patients in the grade 1 mucositis cohort were lower than those observed in patients without mucositis. There was no application site irritation reported in any patient, regardless of mucositis status. Mild somnolence was reported by two patients with mucositis. There were no deaths or serious adverse events reported in this study.

CONCLUSION

The results of this study indicate that application of FBSF to an area of grade 1 mucositis does not result in increased fentanyl exposure or irritation of the mucosa. The 200 μg dose of FBSF was well tolerated.

HPLC-UV method development for fentanyl determination in rat plasma and its application to elucidate pharmacokinetic behavior after i.p. administration to rats

A simple, rapid and validated high performance liquid chromatography method with UV detection for the quantification of an opioid agonist, fentanyl (FEN), in rat plasma was developed. The assay procedure involved chromatographic separation using a ZIC-HILIC SeQUANT column (250 mm × 4.6 mm, i.d., 5 μm) and a mobile phase of acetonitrile and acetate buffer (pH 3.4, 20mM) of ratio (=65:35, v/v) at a flow rate of 1.2 mL/min and detection wavelength of 201 nm. Plasma sample (100 μL) pretreatment was based on simple deprotienization by acetonitrile spiked with clonidine as an internal standard (I.S.) of 20 ng/mL followed by extraction with tert-butyl methyl ether and centrifugation. The organic layer was evaporated under N(2) gas and reconstituted with 100 μL of acetate buffer (pH 3.4, 20mM), and 50-μL portions of reconstituted sample were injected onto the column. Sample analysis including sample pretreatment was achieved within 35 min. Calibration curve was linear (r ≥ 0.998) from 5 to 100 ng/mL. Both intra- and inter-day assay precisions that are presented through RSD were lower than 12.6% for intra-day and lower than 12.0% for inter-day assessment. Limit of detection was 0.8 ng/mL at S/N of 3. This method was omitting the use of expensive solid phase extraction and time consuming liquid extraction procedures. Moreover, the present method was successfully applied to study pharmacokinetic parameters of FEN after intraperitoneal administration to male Wistar rat. Pharmacokinetic parameters estimated by using moment analysis were T(1/2) 198.3 ± 44.7 min, T(max) 28.3 ± 2.9 min and AUC(0-180) 15.6 ± 2.9(× 10(2))ngmin/mL.

Intra- and interindividual variabilities in the pharmacokinetics of fentanyl buccal soluble film in healthy subjects: a cross-study analysis

BACKGROUND AND OBJECTIVE

Breakthrough pain describes transient exacerbations of pain that occur in cancer patients with adequately controlled background pain. Transmucosal fentanyl administration produces rapid-onset and short-duration analgesia that is effective for treating patients with breakthrough pain. Although a significant amount of research has been devoted to the study of speed of analgesia onset of transmucosal fentanyl products, few data exist on their variability in absorption, particularly within the same individual, despite the importance of this characteristic to the dose-to-dose reliability of their analgesic effect. This cross-study analysis aimed to evaluate the intra- and interindividual pharmacokinetic differences of fentanyl administered via fentanyl buccal soluble film in healthy subjects.

METHODS

Data were evaluated from 24 subjects in two pharmacokinetic studies of fentanyl administered via fentanyl buccal soluble film (Breakyl®/Onsolis™; BEMA® [BioErodible MucoAdhesive] technology). In one study, 12 healthy subjects received 600 μg doses of fentanyl as single film on two separate occasions; in the second study, 12 different healthy subjects received 800 μg doses of fentanyl on two separate occasions, one as a single 800 μg film and the other as four 200 μg films.

RESULTS

The analysis showed a minimal intraindividual variability and a relatively higher interindividual variability in pharmacokinetic parameters (i.e. maximum plasma concentration, area under the plasma concentration-time curve from time zero to infinity). The coefficient of variation for intraindividual exposure to fentanyl variability was 7-10%, and for interindividual variability was 23-39%.

CONCLUSION

The minimal intraindividual variability in fentanyl absorption from the buccal soluble film demonstrates a predictable dose-to-dose exposure, which is a very desirable attribute for a medicine that is intended to treat breakthrough cancer pain, suggesting that this product would be expected to produce consistent effects in clinical practice. The greater interindividual variability highlights the need for individual titration of this product (as occurs with similar transmucosal fentanyl products), and for the availability of an adequately wide dose range.

The management of cancer pain

The experience of pain in cancer is widely accepted as a major threat to quality of life, and the relief of pain has emerged as a priority in oncology care. Pain is associated with both the disease as well as treatment, and management is essential from the onset of early disease through long-term survivorship or end-of-life care. Effective relief of pain is contingent upon a comprehensive assessment to identify physical, psychological, social, and spiritual aspects and as a foundation for multidisciplinary interventions. Fortunately, advances in pain treatment and in the field of palliative care have provided effective treatments encompassing pharmacological, cognitive-behavioral, and other approaches. The field of palliative care has emphasized that attention to symptoms such as pain is integral to quality cancer care.

Efficacy and safety of fentanyl buccal for cancer pain management by administration through a soluble film: an update

More than half of patients receiving prescription medicine for cancer pain have been reported to experience inadequate pain relief or breakthrough pain. Buccal administration can deliver lipophilic opioids rapidly to the systemic circulation through the buccal mucosa, limiting gastrointestinal motility and first-pass metabolism. This review updates the safety and efficacy of fentanyl buccal soluble film (FBSF) in patients with cancer pain. Literature was identified through searches of Medline (PubMed). Search terms included combinations of the following: cancer pain, fentanyl, fentanyl buccal soluble film, pharmacology, kinetics, safety, efficacy and toxicity. FBSF is an oral transmucosal form of fentanyl citrate developed as a treatment of breakthrough pain in opioid-tolerant patients with cancer. Studies have shown that it is well tolerated in the oral cavity, with adequate bioavailability and safety in cancer patients. Further studies are warranted to evaluate, in comparison with other short-acting opioids, its efficacy in the management of breakthrough cancer pain, its addictive potential and its economic impact in cancer patients.