Chronomodulated drug delivery system of salbutamol sulphate for the treatment of nocturnal asthma

Circadian Disruption in Night Shift Work and Its Association with Chronic Pulmonary Diseases

Globalization and the expansion of essential services over continuous 24 h cycles have necessitated the adaptation of the human workforce to shift-based schedules. Night shift work (NSW) causes a state of desynchrony between the internal circadian machinery and external environmental cues, which can impact inflammatory and metabolic pathways. The discovery of clock genes in the lung has shed light on potential mechanisms of circadian misalignment in chronic pulmonary disease. Here, the current knowledge of circadian clock disruption caused by NSW and its impact on lung inflammation and associated pathophysiology in chronic lung diseases, such as asthma, chronic obstructive pulmonary disease, pulmonary fibrosis, and COVID-19, is reviewed. Furthermore, the limitations of the current understanding of circadian disruption and potential future chronotherapeutic advances are discussed.

Designing the formulations in circadian rhythm activity with chronotherapeutic drug delivery system using ramelteon

Ramelteon is an orally sleep promoting agent that is chemically designated as (S)- N- [2-(1,6,7,8-Tetrahydro-2H-indeno-[5,4b] furan-8-yl) ethyl] propionamide and contains one chiral centre. Ramelteon is a neutral compound with no acid or base functional groups, and as such, its aqueous solubility is independent of pH. The activity of Ramelteon at the MT1and MT2 receptors is believed to contribute to its sleep-promoting properties, as these receptors, acted upon by endogenous melatonin, are thought to be involved in the maintenance of the circadian rhythm underlying the normal sleep-wake cycle. These maintenance of circadian rhythm can be well controlled by designing the formulations with chronotherapeutic drug delivery system. This article summarizes to design, develop and evaluate the chronotherapeutic drug delivery system with various approaches using control release polymers like Eudragit RSPO, Hydroxy propyl methyl cellulose (HPMC), Ethyl cellulose etc., the approaches like compression coating technique, pulsatile drug delivery system and coating technique. The main objective of controlling the drug release pattern is to achieve the lag time of 2 hours followed by drug release profile for 4 hours. Also an attempt has been made to conclude on various approaches studied which can be used in the treatment of circadian rhythm using Ramelteon API.

Recent Advances in Chronotherapy Targeting Respiratory Diseases

Respiratory diseases contribute to a significant percentage of mortality and morbidity worldwide. The circadian rhythm is a natural biological process where our bodily functions align with the 24 h oscillation (sleep-wake cycle) process and are controlled by the circadian clock protein/gene. Disruption of the circadian rhythm could alter normal lung function. Chronotherapy is a type of therapy provided at specific time intervals based on an individual's circadian rhythm. This would allow the drug to show optimum action, and thereby modulate its pharmacokinetics to lessen unwanted or unintended effects. In this review, we deliberated on the recent advances employed in chrono-targeted therapeutics for chronic respiratory diseases.

Emerging concepts and directed therapeutics for the management of asthma: regulating the regulators

Asthma is a common, heterogeneous and serious disease, its prevalence has steadily risen in most parts of the world, and the condition is often inadequately controlled in many patients. Hence, there is a major need for new therapeutic approaches. Mild-to-moderate asthma is considered a T-helper cell type-2-mediated inflammatory disorder that develops due to abnormal immune responses to otherwise innocuous allergens. Prolonged exposure to allergens and persistent inflammation results in myofibroblast infiltration and airway remodelling with mucus hypersecretion, airway smooth muscle hypertrophy, and excess collagen deposition. The airways become hyper-responsive to provocation resulting in the characteristic wheezing and obstructed airflow experienced by patients. Extensive research has progressed the understanding of the underlying mechanisms and the development of new treatments for the management of asthma. Here, we review the basis of the disease, covering new areas such as the role of vascularisation and microRNAs, as well as associated potential therapeutic interventions utilising reports from animal and human studies. We also cover novel drug delivery strategies that are being developed to enhance therapeutic efficacy and patient compliance. Potential avenues to explore to improve the future of asthma management are highlighted.

Bilayer Tablet Based Chronotherapeutics in the Management of Nocturnal Asthma: An Overview

BACKGROUND

Asthma is a common ailment with a larger circadian difference. Nocturnal Asthma (NA) is an inconstant exacerbation of asthmatic condition related to the rise in warning sign during the night time and there is a need for its treatment addressing air route alertness and decline in lung functions. These symptoms are linked to sleep or known as circadian events. Chronotherapeutics is a management system based on an in-vivo drug accessibility programmed to check the rhythms of ailment in a direction to improve the therapeutic outcomes by suppressing the side effects. This review aims to provide an overview of NA, chronotherapeutics for the treatment of NA, bilayer tablets, and advanced techniques involved in the fabrication of bilayer tablets. The review also discusses some of the related patents.

METHODS

Relevant literature about the latest developments and updated information related to NA, chronotherapeutics and bilayer tablets has been very widely searched on different biomedical literature programs such as Google, Web of Science, PubMed portals, etc. Bilayer tablet mediated chronotherapy has gained significant attention and consideration as it is developed and fabricated based on the body's circadian rhythm. Bilayer tablets can deliver the bioactive compounds at an appropriate time, place as well as amount and site.

RESULTS

Available literature advocated that the bilayer matrix tablet containing a single drug in the sustained release film and fast releasing film, may be beneficial for the chronic diseases like asthma, migraine, diabetes, hypertension and inflammation which usually require immediate as well as maintained therapeutic effect.

CONCLUSION

The application of nanotechnology in the arena of medicine will transform the diagnosis and treatment strategies of a wide range of diseases in the upcoming years. The findings of this review confirm the importance of bilayer tablet based chronotherapy in nocturnal asthma.

Chronomodulated drug delivery system of urapidil for the treatment of hypertension

Introduction:

Hypertension is a disease which shows circadian rhythm in the pattern of two peaks, one in the evening at about 7pm and other in the early morning between 4 am to 8 am. Conventional therapies are incapable to target those time points when actually the symptoms get worsened. To achieve drug release at two time points, chronomodulated delivery system may offer greater benefits.

Materials and methods:

The chronomodulated system comprised of dual approach; immediate release granules (IRG) and pulsatile release mini-tablets (PRM) filled in the hard gelatin capsule. The mini-tablets were coated using Eudragit S-100 which provided the lag time. To achieve the desired release, various parameters like coating duration and coat thickness were studied. The immediate release granules were evaluated for micromeritical properties and drug release, while mini-tablets were evaluated for various parameters such as hardness, thickness, friability, weight variation, drug content, and disintegration time and in-vitro drug release. Compatibility of drug-excipient was checked by fourier transform infrared spectroscopy and Differential scanning calorimetry studies and pellets morphology was done by Scanning electron microscopy studies.

Results:

The in-vitro release profile suggested that immediate release granules gives drug release within 20 min at the time of evening attack while the programmed pulsatile release was achieved from coated mini-tablets after a lag time of 9hrs, which was consistent with the demand of drug during early morning hour attack. Pellets found to be spherical in shape with smooth surface. Moreover compatibility studies illustrated no deleterious reaction between drug and polymers used in the study.

Conclusions:

The dual approach of developed chronomodulated formulation found to be satisfactory in the treatment of hypertension.

Development of time controlled chronomodulated tablet with swelling and rupturable layers: Optimization of factors influencing lag-time and drug release

Introduction:

A tablet system consisting of cores coated with two layers of swelling and rupturable coatings was prepared and evaluated as time controlled chronomodulated tablet.

Materials and Methods:

Cores containing Montelukast sodium as model drug were prepared by direct compression and then coated sequentially with an inner swelling layer containing a HPMC E 5 and an outer rupturable layer of Eudragit RL/RS (1:1). A three-factor, two-level, full factorial design was used to investigate the influence of amount of HPMC E 5 and Eudragit RL/RS (1:1) on the responses, i.e., lag time to release and time required for 80% of drug to releases. The dissolution tests were studied using the USP paddle method at 50 rpm in 0.1 N HCL for 2 hr and than in phosphate buffer pH 6.8.

Methods:

Cores containing Montelukast sodium as model drug were prepared by direct compression and then coated sequentially with an inner swelling layer containing a HPMC E 5 and an outer rupturable layer of Eudragit RL/RS (1:1). A three-factor, two-level, full factorial design was used to investigate the influence of amount of HPMC E 5 and Eudragit RL/RS (1:1) on the responses, i.e., lag time to release and time required for 80% of drug to releases. The dissolution tests were studied using the USP paddle method at 50 rpm in 0.1 N HCL for 2 hr and than in phosphate buffer pH 6.8.

Result:

The lag time of the drug release decreased by increasing the inner swelling layer and increased by increasing the rupturing layer level.

Conclusion:

The results obtain from present study suggest that swelling come reputable coating approach gives desire drug release after lag time.

Timing is important in medication administration: a timely review of chronotherapy research

BACKGROUND

Chronotherapy involves altering the timing of medication administration to improve the overall control of a disease and to minimise treatment side-effects, and is an emerging concept in the field of therapeutics.

AIM

The aim of this review is to conduct an in-depth analysis of the recent literature in order to identify and evaluate the evidence base for drug chronotherapy.

METHOD

A literature search was conducted in three databases (Medline, Embase, International Pharmaceutical Abstracts) using the search terms "Chronotherapy", "Chronopharmacology", "Chronopharmacokinetics", "Chronopharmacodynamics", "Chronoefficacy", "Chronoformulation", "Morning and Evening", "Morning and Bedtime" and their combinations. The selection criteria for the inclusion of articles in the review included currency (years 2008-Aug 2011), publication in English language, studies done in Humans and non-review articles that pertained to 'drug' therapy.

RESULTS

Our search revealed a total of 192 journal articles, of which 41 articles were selected for review. The specific hypothesis for the effectiveness of chronotherapy that was tested in these 41 studies was chronoeffectiveness (n = 34), followed by chronopharmacokinetics (n = 5), chronomodulation (n = 3) and chronopharmacodynamics (n = 2). The findings from two-thirds (n = 27) of the reviewed studies, support the notion of chronotherapy.

CONCLUSION

The review presents the scope of chronotherapy in drug utilization. We believe that the knowledge of chronotherapy is growing and the current research for chronotherapy is promisingly in the conceptualization or early experimental phase. Going forward, chronotherapy studies should also explore genetic, gender and age related differences. Preliminary screening of new drugs for chronotherapeutic potential may be a way of enhancing quality use of medicines.

Development and characterization of chronomodulated drug delivery system of captopril

Background:

Hypertension shows circadian rhythm that there is a rise in pressure from the time of waking or before (about 4 to 8 a.m.), in most people. Conventional drug delivery system of captopril is inappropriate for the delivery of drug, as they cannot be administered just before the symptoms are worsened, because during this time the patients are asleep, bedtime dosing of captopril will not provide a therapeutic plasma drug concentration at the early hours of morning because of poor pharmacokinetic profile and shorter half-life of 1.9 hours. Thus, this study attempts to design and evaluate a chronomodulated pulsatile drug delivery system of captopril which was aimed to release the drug after a lag time of 6 hours.

Materials and Methods:

Present delivery system was prepared by rupturable coating method. The core containing captopril as a bioactive compound were prepared by direct compression method and then coated sequentially with an inner swelling layer containing hydrocolloid HPMC E5 and an outer rupturable layer consisted of Eudragit RL/RS (1 : 1). Total 12 formulations with different levels of inner swelling layer and outer polymeric layer were prepared and subjected to various processing and formulative parameters like the effect of core composition, level of swelling layer, and rupturable coating on lag time was investigated. In vitro drug release and rupture tests were performed using United States Pharmacopoeia paddle method at 50 rpm in 0.1N HCl and phosphate buffer of pH 6.8.

Results:

The results showed that as the amount of inner swelling layer increases, the lag time decreases and as the Eudragit coating level increases, the lag time increases and percent water uptake of time-dependent pulsatile release system decreases. The presence of an osmotic agent and effervescent agent helped in shortening of lag time.

Conclusion:

The system was found to be satisfactory in terms of release of the drug after the lag time of 6 hours.

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.

Formulation and evaluation of press coated tablets for pulsatile drug delivery using hydrophilic and hydrophobic polymers

The aim of present investigation was to develop press coated tablet for pulsatile drug delivery of ketoprofen using hydrophilic and hydrophobic polymers. The drug delivery system was designed to deliver the drug at such a time when it could be most needful to patient of rheumatoid arthritis. The press coated tablets containing ketoprofen in the inner core was formulated with an outer shell by different weight ratio of hydrophobic polymer (micronized ethyl cellulose powder) and hydrophilic polymers (glycinemax husk or sodium alginate). The release profile of press coated tablet exhibited a lag time followed by burst release, in which outer shell ruptured into two halves. Authors also investigated factors influencing on lag time such as particle size and viscosity of ethyl cellulose, outer coating weight and paddle rpm. The surface morphology of the tablet was examined by a scanning electron microscopy. Differential scanning calorimeter and Fourier transformed infrared spectroscopy study showed compatibility between ketoprofen and coating material.