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Marine Biopolymers
Published in Se-Kwon Kim, Marine Biochemistry, 2023
The controlled-release technology is getting more interest for many advantages comparing to the conventional medical drugs. In normal medicine (as a tablet or pill), after administration, the drugs dissolve quickly in stomach or intestine into a liquid and then release the active substance into plasma and distribute throughout the body. However, once entering the body, the process of elimination begins. The drug is metabolized in the liver and passes out the body through urine, breath, sweat or with small quantities in saliva and breast milk. This process causes the strong fluctuation of the drug content in plasma: the very high drug content may be up to a toxic level in the early time after administration and may cause side effects to the patients; the duration of effective drug content is short, then the content decreased to an inappropriate value (Moodley et al., 2012). This situation introduces to increase the frequency of administration, makes the patients uncomfortable by short time of effectiveness and more side effects. The controlled-release technology is based on the absorption or entrapping of the drug into the matrix gel of biopolymer as alginate of chitosan. When the drug moves into the gastric intestinal tract, the gel is degraded and that releases the drug gradually. This technology can eliminate the limits of the conventional drugs (Kumar, 2000).
Selected topics
Published in Henry J. Woodford, Essential Geriatrics, 2022
Lamotrigine's potential adverse effects include rash, insomnia and tremor. Doses have to be slowly titrated upwards at two-week intervals and takes around six weeks to reach the lower end of the therapeutic range. Sodium valproate may cause tremor and weight gain. There is some limited evidence from heterogeneous populations (also used as a mood stabiliser) that it could occasionally cause parkinsonism.49 There have been rare reports of valproate-induced hyperammonaemic encephalopathy.50 Carbamazepine tends to be the least well tolerated AED in older people.47,48 It has a higher risk of drug interactions and hyponatraemia (secondary to SIADH).46 It can also cause a rash. It is usually best avoided in older people.39 When prescribed, controlled release formulations may cause fewer adverse effects.43 Gabapentin is associated with weight gain, tremor and ataxia. Possible adverse effects from levetiracetam include reduced concentration, drowsiness, depression, agitation and irritability.39 Psychosis has also been reported with levetiracetam and topiramate.51 Psychiatric disorders were the commonest adverse event with levetiracetam (26–30% of relatively young people in randomised studies).44,45 AEDs can increase the risk of osteoporosis.
Fenugreek
Published in Dilip Ghosh, Prasad Thakurdesai, Fenugreek, 2022
Ujjwala Kandekar, Sunil Ramdasi, Prasad Thakurdesai
Sustained and controlled release tablets are intended to modify the drug release rate for a prolonged period with the help of customized polymers (Ainurofiq and Choiri 2015; Cazorla-Luna et al. 2019; Mylangam et al. 2016; Ofori-Kwakye et al. 2016). The sustained release tablets help to maintain the constant plasma of drug concentration and retards the release rate of the drug, thereby extending the duration of action (Sharma et al. 2019).
Novel formulations of metal-organic frameworks for controlled drug delivery
Published in Expert Opinion on Drug Delivery, 2022
Congying Rao, Donghui Liao, Ying Pan, Yuyu Zhong, Wenfeng Zhang, Qin Ouyang, Alireza Nezamzadeh-Ejhieh, Jianqiang Liu
Achieving the aim of targeting drug-controlled release without affecting drugs’ therapeutic effect and bioavailability is currently one of the main difficulties when developing nanosystem drug release. According to the complexity and control level, the evolution of drug-controlled release has been classified into four generations: no controlled release, endogenous stimulus release, exogenous stimulus release, or multi-response stimulation release, and integration of diagnosis and treatment. (Figure 3(a)). No-controllable systems are known for their simplicity and are suitable for unrequired drug delivery. The stimulus-response-based drug-controlled release has an excellent controllable release property and can meet various on-demand drug releases. The stimulus can be endogenous to initiate local drug release and promote its therapeutic effect (e.g. pH, redox activity, etc). Or exogenous (e.g. light, magnetic field, temperature, etc). This drug-controlled release always has a certain degree of spatial and temporal control, which can be designed to diagnose disease and achieve drug-controlled release and diagnosis. Based on the superiority of easy functionalization, MOFs have been utilized to construct various response systems modes (Figure 3(b)) [91–97]. Therefore, MOFs controlled release might be a perfect answer to the abovementioned problem.
Design of experiments and multivariate analysis approach to study dissolution stability of a modified-release drug product to support lean design strategies
Published in Drug Development and Industrial Pharmacy, 2021
Nika Jordan, Robert Roškar, Iztok Grabnar
Controlled release drug formulations have become an integral part of the pharmaceutical industry since the 60’s [1]. The aim of the formulations that are able to control drug release is to reduce the negative aspect that is caused by frequent dosing of immediate release tablets and to improve the therapeutic effects of a certain drug [2–4]. There are multiple ways in which drugs can be formulated to achieve the desired property of release. Among the most frequently used systems for oral controlled drug delivery are hydrophilic matrix systems as they are cost effective and can reproduce a desirable drug release profile [5,6]. Polyethylene oxide (PEO) is a possible alternative to the most common polymer hydroxypropyl methylcellulose (HPMC) for the controlled polymeric matrix system. Due to its hydrophilic character, PEO swells upon contact with body fluids [7–9]. It is well known that PEO matrix tablets can release drugs in vitro over a long period. However, when administered in vivo, PEO often failed to release the drug efficiently, due to insufficient PEO hydration in the gastrointestinal tract [10,11]. Polyethylene glycol (PEG) is often used in formulations as a filler and a gel-enhancing agent. It promotes water uptake into the hydrogel and undergoes to complete gelation within a few hours. Sako et al. demonstrated that a combination of PEG and PEO was useful as an oral controlled absorption system (OCAS) [12]. PEO/PEG matrix tablets have the key features of rapid water uptake and the resulting complete gelation of the polymeric excipients within a few hours [13].
Clinical treatment of intra-epithelia cervical neoplasia with photodynamic therapy
Published in International Journal of Hyperthermia, 2020
Antonio Carlos Figueiredo Vendette, Henrique Luis Piva, Luis Alexandre Muehlmann, Delfrank Ananias de Souza, Antonio Claudio Tedesco, Ricardo Bentes Azevedo
Drug delivery systems (DDS) represents one of the most promising fields in science, developed to contribute to the improvement of both human and animal health, offering several advantages to conventional pharmaceutical therapies and drug formulation. The investigation of controlled release systems, including the modulation of the dissolution process, reduction of toxicity, and increase of drug uptake, makes it an acceptable and convenient clinical protocol for the patient. Furthermore, these strategies can also make active drugs more available to the specific target tissues, inducing a better and faster therapeutic effect [1]. The development of this new generation of pharmaceutical formulation, allowing the optimization of drug release speed, and the improvement of the dose regime through the controlled release of assets into specific target sites, has been the main goals of numerous studies in recent years [2]. Among the biocompatible raw materials employed in such studies, liposomes, microparticles, and polymeric or lipid nanoparticles are highlighted [3].