The Contin delivery system: dosing considerations

Montelukast medicines of today and tomorrow: from molecular pharmaceutics to technological formulations

Montelukast sodium is a leukotriene antagonist of growing interest as an alternative therapy for asthma across different age groups due to its bronchoprotective, anti-inflammatory and anti-allergic properties. Currently, montelukast is commercialized only in oral solid dosage forms, which are the favorite of adult patients but may pose challenges in administration to children of young age or patients suffering from dysphagia. This review presents a comprehensive revision of scientific reports and patents on emerging strategies for the delivery of montelukast. A common ground to these reports is the pursue of an enhanced montelukast performance, by increasing its bioavailability and physico-chemical stability. A wide variety of strategies can be found, from the formation of supramolecular adducts with cyclodextrins to encapsulation in nanoparticles and liposomes. The new dosage forms for montelukast are designed for non-enteric absorption, some for absorption in the oral cavity and another two being for local action in the nasal mucosa or in the pulmonary epithelium. The review describes the emerging delivery strategies to circumvent the current limitations to the use of montelukast that are expected to ultimately lead to the development of more patient-compliant dosage forms.

Chronotherapeutics--a chronopharmaceutical approach to drug delivery in the treatment of asthma

Bronchial asthma is a chronic inflammatory disorder of the airways associated with airflow obstruction that is reversible spontaneously or with treatment. Bronchial asthma is a disease based on established circadian rhythm. The symptoms of asthma worsen during midnight to early morning and therefore it is required to deliver the drug in such fashion that effective treatment can be obtained during the time of asthma attacks. Chronotherapy is an approach that fulfills the criteria of drug delivery at a specific time as per the pathophysiological need of the disease, to improve patient compliance. The current article focuses on the chronotherapy of bronchial asthma, methodologies involved for the existing systems, recent updates and different chronopharmaceutical technologies currently available in the market. Chronotherapy with different categories of bronchial asthma medications also has been reviewed.

Extended-release morphine sulfate in treatment of severe acute and chronic pain

Morphine is the archetypal opioid analgesic. Because it is a short-acting opioid, its use has been limited to the management of acute pain. The development of extended-release formulations have resulted in the increased utilization of morphine in chronic pain conditions. This review documents the history of morphine use in pain treatment, and describes the metabolism, pharmacodynamics, formulations, and efficacy of the currently available extended-release morphine medications.

Drug delivery technologies for chronotherapeutic applications

It has been proven that the body follows a 24-hour cycle called a circadian rhythm. This cycle is coordinated by the suprachiasmatic nucleus and controls nearly all bodily functions including those related to drug delivery. Knowledge of the body's circadian rhythm leads to an improved understanding of diseases and their treatment, known as chronotherapy, such that synchronizing drug application in accordance with the natural rhythm of the body leads to improved disease management and a greater patient therapeutic outcome. Chronotherapeutic diseases include asthma, cardiovascular diseases, glaucoma, rheumatoid arthritis and cancers. In order to treat these diseases numerous chronotherapeutic drug delivery systems have been developed, such that drug is released in the period when it is most needed. This review paper attempts to concisely explicate the role of circadian rhythms in various disease states and furthermore describes the various oral drug delivery technologies that have been employed for the treatment of chronotherapeutic diseases.

Advanced formulation design: improving drug therapies for the management of severe and chronic pain

Chronic pain is a condition affecting a vast patient population and resulting in billions of dollars in associated health care costs annually. Sufferers from severe chronic pain often require [correction of requite] twenty-four hour drug treatment through intrusive means and/or repeated oral dosing. Although the oral route of administration is most preferred, conventional immediate release oral dosage forms lead to inconvenient and suboptimal drug therapies for the treatment of chronic pain. Effective drug therapies for the management of chronic pain therefore require advanced formulation design to optimize the delivery of potent analgesic agents. Ideally, these advanced delivery systems provide efficacious pain therapy with minimal side effects via a simple and convenient dosing regime. In this article, currently commercialized and developing drug products for pain management are reviewed with respect to dosage form design as well as clinical efficacy. The drug delivery systems reviewed herein represent advanced formulation designs that are substantially improving analgesic drug therapies.

Overview of oral modified-release opioid products for the management of chronic pain

OBJECTIVE

To evaluate pharmaceutical and pharmacotherapeutic differences in oral opioid modified-release products used in the management of chronic pain.

DATA SOURCES

Searches of MEDLINE (1966-May 2006) and an extensive review of peer reviewed journals were conducted using the key search terms opioid, morphine, hydromorphone, and oxycodone. Supplemental information was gathered through the American Pain Society, and limited but relevant information was obtained from manufacturers' labeling.

STUDY SELECTION AND DATA EXTRACTION

All articles identified from the data sources were evaluated. Information deemed relevant was included for this review if it introduced new or well supported concepts or clarified clinical practice issues.

DATA SYNTHESIS

The recognition and treatment of pain has become a major focus of healthcare professionals. The Joint Commission on Accreditation of Healthcare Organizations mandates compliance with recommended standards, outcome measures, and other initiatives. A general review of pain management and pharmacokinetic parameters are included.

CONCLUSIONS

Oral modified-release products have enabled patients to better maintain pain control due to convenient dosing intervals and sustained blood concentrations. The differences between available oral modified-release products are half-life, cost, and formulation (excipients and drug-release properties).

Chronopharmaceutics: gimmick or clinically relevant approach to drug delivery?

Due to advances in chronobiology, chronopharmacology, and global market constraints, the traditional goal of pharmaceutics (e.g. design drug delivery systems with a constant drug release rate) is becoming obsolete. However, the major bottleneck in the development of drug delivery systems that match the circadian rhythm (chronopharmaceutical drug delivery systems: ChrDDS) may be the availability of appropriate technology. The last decade has witnessed the emergence of ChrDDS against several diseases. The increasing research interest surrounding ChrDDS may lead to the creation of a new sub-discipline in pharmaceutics known as chronopharmaceutics. This review introduces the concept of chronopharmaceutics, addresses theoretical/formal approaches to this sub-discipline, underscores potential disease-targets, revisits existing technologies and examples of ChrDDS. Future development in chronopharmaceutics may be made at the interface of other emerging disciplines such as system biology and nanomedicine. Such novel and more biological approaches to drug delivery may lead to safer and more efficient disease therapy in the future.

Food interactions with sustained-release theophylline preparations. A review

Currently, theophylline is being used predominantly as sustained-release capsules or tablets. In the mid-seventies the first preparations for use with a dosage interval of 12 hours (twice-daily preparations) were introduced. Since 1983, theophylline preparations that can be given with an interval of 24 hours (once-daily preparations) have become available. The release of theophylline from some of these products can be influenced (either increased or decreased) by concomitant intake of food. With some preparations the composition of the meal (especially the fat content) has an influence on the degree of effect. The consequence may be an effect on the rate of absorption or on the amount absorbed, or both simultaneously. This could result in an unexpected shift of the plasma theophylline concentration. Such a shift is therapeutically undesirable, because theophylline has a fairly narrow therapeutic range. A review is given of those food interactions with the sustained-release theophylline preparations, both twice-daily and once-daily products, that are currently on the world market. Special attention is paid to the specific (bio)pharmaceutical characteristics of the different products, and to the influence of the composition and timing of the meals. For each preparation the effect of food on the following pharmacokinetic parameters is discussed: area under the plasma concentration-time curve, peak plasma drug concentration and time to reach this peak. Where possible, the results for both adults and children are discussed. There are indications that children are more susceptible to food-effects than adults. The regulatory aspects are mentioned briefly. Clinically important effects of food have been observed with the following twice-daily products: 'Theo-Dur Sprinkle', 'Theolair SR' (= 'Nuelin SR') and 'Theograd'. Pronounced effects could have an even greater impact with once-daily preparations, as the total daily dose will be given at a single time. A particularly sudden release of a major part of the dose ('dose-dumping') may result in toxic plasma concentrations. Among these products, clinically important effects in children have been reported with 'Theo-24' and 'Uniphyl'.

Food interactions with once-a-day theophylline preparations: a review

At present, theophylline is used predominantly as sustained-release dosage forms. Since the mid-seventies many such products have been introduced and have found huge application for use with a dosage interval of 12 hr ('twice-a-day' preparations). Since 1983 theophylline has also been available as preparations that can be given with an interval of 24 hr ('once-a-day' preparations). The release of theophylline from sustained-release dosage forms can be influenced (either increased or decreased) by concomitant intake of food. Obviously, ultra-slow-releasing products are most vulnerable to food effects. With some preparations the composition of the meal, especially its fat content, determines the degree of the food effect. The effect of meal timing and content on once-a-day theophylline preparations must be known since rather large doses are ingested all at a single time. If food can alter the release of theophylline in an unexpected manner from ultra-slow preparations, drug effectiveness may be impaired if release is inhibited or toxicity might result if sudden release of drug occurs. Herein, information about food interaction with once-a-day theophylline preparations is reviewed as this topic is important both for clinicians as well as those concerned with chronopharmacologic investigations of such medications.