The Importance of Gut Wall Metabolism in Determining Drug Bioavailability

Author(s):  
Kevin Beaumont
Keyword(s):  
Author(s):  
Bhikshapathi D. V. R. N. ◽  
Haarika B ◽  
Jyothi Sri S ◽  
K Abbulu

The purpose of present investigation was to develop floating matrix tablets of gemifloxacin mesylate, which after oral administration could prolong the gastric residence time, increase the drug bioavailability and diminish the side effects of irritating drugs. Tablets containing drug, various viscosity grades of hydroxypropyl methylcellulose such as HPMC K4M and HPMC K15M as matrix forming agent, Sodium bicarbonate as gas-forming agent and different additives were tested for their usefulness in formulating gastric floating tablets by direct compression method. The physical parameters, in vitro buoyancy, release characteristics and in vivo radiographic study were investigated in this study. The gemifloxacin mesylate floating tablets were prepared using HPMC K4M polymer giving more sustained drug release than the tablet containing HPMC K15M. All these formulations showed floating lag time of 30 to 47 sec and total floating time more than 12 h. The drug release was decreased when polymer concentration increases and gas generating agent decreases. Formulation that contains maximum concen-tration of both HPMC K15M and sodium bicarbonate (F9) showing sufficiently sustained with 99.2% of drug release at 12 h. The drug release from optimized formulation follows Higuchi model that indicates the diffusion controlled release. The best formulation (F9) was selected based on in vitro characteristics and used in vivo radiographic studies by incorporating barium sulphate as a radio-opaque agent and the tablet remained in the stomach for about 6 h.   


Author(s):  
Neeraj Singh ◽  
Shweta Rai ◽  
Sankha Bhattacharya

Background: About two-third of new drugs reveal low solubility in water due to that; it becomes difficult for formulation scientists to develop oral solid dosage forms with a pharmaceutically acceptable range of therapeutic activity. In such cases, S-SMEEDS are the best carrier used universally for the delivery of hydrophobic drugs. SEDDS were also used, but due to its limitations, S-SMEDDS used widely. These are the isotropic mixtures of oils, co-solvents, and surfactants. S-SMEDDS are physically stable, easy to manufacture, easy to fill in gelatin capsules as well as improves the drug bioavailability by releasing the drug in the emulsion form to the gastrointestinal tract and make smooth absorption of the drug through the intestinal lymphatic pathway. Methods: We took on the various literature search related to our review, including the peer-reviewed research, and provided a conceptual framework to that. Standard tools are used for making the figures of the paper, and various search engines are used for the literature exploration.In this review article the author discussed the importance of S-SMEDDS, selection criteria for excipients, pseudo-ternary diagram, mechanism of action of S-SMEDDS, solidification techniques used for S-SMEDDS, Characterization of SEDDS and S-SMEDDS including Stability Evaluation of both and future prospect concluded through recent findings on S-SMEDDS on Cancer as well as a neoteric patent on S-SMEDDS Results: Many research papers discussed in this review article, from which it was found that the ternary phase diagram is the most crucial part of developing the SMEDDS. From the various research findings, it was found that the excipient selection is the essential step which decides the strong therapeutic effect of the formulation. The significant outcome related to solid-SMEDDS is less the globule size, higher would be the bioavailability. The adsorption of a solid carrier method is the most widely used method for the preparation of solid-SMEDDS. After review of many patents, it is observed that the solid-SMEDDS have a strong potential for targeting and treatment of a different type of Cancer due to their property to enhance permeation and increased bioavailability. Conclusion: S-SMEEDS are more acceptable pharmaceutically as compare to SEDDS due to various advantages over SEDDS viz stability issue is prevalent with SEDDS. A number of researchers had formulated S-SMEDDS of poorly soluble drugs and founded S-SMEDDS as prospective for the delivery of hydrophobic drugs for the treatment of Cancer. S-SMEEDS are grabbing attention, and the patentability on S-SMEDDS is unavoidable, these prove that S-SMEEDS are widely accepted carriers. These are used universally for the delivery of the hydrophilic drugs and anticancer drugs as it releases the drug to the gastrointestinal tract and enhances the systemic absorption. Abstract: Majority of active pharmaceutical ingredients (API) shows poor aqueous solubility, due to that drug delivery of the API to the systemic circulation becomes difficult as it has low bioavailability. The bioavailability of the hydrophobic drugs can be improved by the Self-emulsifying drug delivery system (SEDDS) but due to its various limitations, solid self-micro emulsifying drug delivery systems (S-SMEDDS) are used due to its advantages over SEDDS. S-SMEDDS plays a vital role in improving the low bioavailability of poorly aqueous soluble drugs. Hydrophobic drugs can be easily loaded in these systems and release the drug to the gastrointestinal tract in the form of fine emulsion results to In-situ solubilisation of the drug. In this review article the author's gives an overview of the solid SMEDSS along with the solidification techniques and an update on recent research and patents filled for Solid SMEDDS.


2002 ◽  
Vol 55 (1-2) ◽  
pp. 5-12 ◽  
Author(s):  
Kornelija Djakovic-Svajcer

Food can exert a significant influence on the effects of certain drugs. The interactions between food and drugs can be pharmacokinetic and pharmacodynamic. Pharmacokinetic interactions most often take place on absorption and drug metabolism levels. Absorption can be either accelerated or delayed, increased or decreased, while drug metabolism can be either stimulated or inhibited. The factors which influence food-drug interactions are as follows: composition and physic-chemical properties of drugs, the interval between a meal and drug intake and food composition. Food consistency is of lesser influence on drug bioavailability than food composition (proteins, fats, carbohydrates, cereals). Important interactions can occur during application of drugs with low therapeutic index, whereby the plasma level significantly varies due to changes in resorption or metabolism (e.g. digoxin, theophyllin, cyclosporin) and drugs such as antibiotics, whose proper therapeutic effect requires precise plasma concentrations.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 608
Author(s):  
Csilla Bartos ◽  
Patrícia Varga ◽  
Piroska Szabó-Révész ◽  
Rita Ambrus

The absorption of non-steroidal anti-inflammatory drugs (NSAIDs) through the nasal epithelium offers an innovative opportunity in the field of pain therapy. Thanks to the bonding of chitosan to the nasal mucosa and its permeability-enhancing effect, it is an excellent choice to formulate microspheres for the increase of drug bioavailability. The aim of our work includes the preparation of spray-dried cross-linked and non-cross-linked chitosan-based drug delivery systems for intranasal application, the optimization of spray-drying process parameters (inlet air temperature, pump rate), and the composition of samples. Cross-linked products were prepared by using different amounts of sodium tripolyphosphate. On top of these, the micrometric properties, the structural characteristics, the in vitro drug release, and the in vitro permeability of the products were studied. Spray-drying resulted in micronized chitosan particles (2–4 μm) regardless of the process parameters. The meloxicam (MEL)-containing microspheres showed nearly spherical habit, while MEL was present in a molecularly dispersed state. The highest dissolved (>90%) and permeated (~45 µg/cm2) MEL amount was detected from the non-cross-linked sample. Our results indicate that spray-dried MEL-containing chitosan microparticles may be recommended for the development of a novel drug delivery system to decrease acute pain or enhance analgesia by intranasal application.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 784
Author(s):  
Aleph M. S. Souza ◽  
Renato C. A. Ribeiro ◽  
Gleyse K. L. O. Pinheiro ◽  
Francisco I. Pinheiro ◽  
Wógenes N. Oliveira ◽  
...  

Onychomycosis induced by Candida spp. has several limitations regarding its treatment. Nail lacquers display the potential to overcome these drawbacks by providing therapeutic compliance and increasing local drug bioavailability. Thus, this work aimed to produce a nail lacquer loaded with Amphotericin B (AmB) and evaluate its performance. The AmB-loaded nail lacquer was produced and preliminarily characterized. An AmB quantification method was developed. Stability, drug release, permeability and anti-Candida activity assays were conducted. The analytical method validation met the acceptance criteria. The drug loading efficiency was 100% (0.02 mg/g of total product), whereas the AmB stability was limited to ≅ 7 days (≅ 90% remaining). The nail lacquer displayed a drying time of 187 s, non-volatile content of around 20%w/w, water-resistance of approximately 2%w/w of weight loss and satisfactory in vitro adhesion. Moreover, the in vitro antifungal activity against different Candida spp. strains was confirmed. The AmB release and the ex vivo permeability studies revealed that AmB leaves the lacquer and permeates the nail matrix in 47.76 ± 0.07% over 24 h. In conclusion, AmB-loaded nail lacquer shows itself as a promising extemporaneous dosage form with remarkable anti-Candida activity related to onychomycosis.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1451.3-1451
Author(s):  
K. Kraev ◽  
M. Geneva-Popova ◽  
S. Popova

Background:Biological drugs are protein derivatives that, as such, are highly immunogenic. In recent years there have been many conflicting opinions about the role of drug immunogenicity in clinical practice.Objectives:To evaluate the drug immunogenicity of TNF-alpha blocking drugs (etanercept and adalimumab) used to treat patients with rheumatoid arthritis. To determine whether their presence can alter the effect of treatment and to evaluate their role in the clinical practice of rheumatologists.Methods:121 patients with rheumatoid arthritis, as well as 31 healthy controls, similar in sex and age, were examined. They were all monitored at 0, 6, 12 and 24 months from the start of TNF-alpha blocker treatment. Demographics, vital signs, markers of inflammation such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and disease activity indices were examined at each visit, respectively. Drug-induced neutralizing antibodies, as well as drug bioavailability in patients treated with adalimumab, were examined by ELISA.Results:Drug-induced neutralizing antibodies to adalimumab were detected in 11.57% of patients at 6 month, in 17.64% of patients at 12 month, and 24.8% at 24 month. Drug-induced neutralizing antibodies to etanercept were not detected at 6 months, at 7.77% at 12 months, at 9.63% of patients at 24 months. Of the adalimumab patients who were having drug-induced antibodies, 92.59% had low drug bioavailability, while the remaining 7.41% of patients showed normal drug bioavailability despite the presence of drug-induced neutralizing antibodies. In terms of worsening of the disease activity, a positive correlation was found with the presence of drug antibodies - Pearson Correlation = 0.701, p = 0.001. Patients with poor clinical response and available drug antibodies receiving adalimumab were slightly more than those treated with etanercept at 12 and 24 months but the difference is non-significant-U = 0.527, p> 0.05 and U = 0.623, p> 0.05, respectively.Conclusion:Presence of drug-induced neutralizing antibodies in patients treated with adalimumab and etanercept has been associated with poor clinical response and worsening of the patient’s condition. Testing of drug-induced neutralizing antibodies as well as the drug bioavailability of the drug used can be used as reliable biomarkers in clinical rheumatology.References:[1]Benucci M., F.Li Gobbi, M. Meacii et al., “Antidrug antibodies against TNF-blocking agents: correlations between disese activity, hypersensitivity reactions, and different classes of immunoglobulins”, Biologics and Targets and Therapy, 2015: 9 7 -2.[2]Chen D., Y. Chen, W. Tsai et al., “ Significant associations of antidrug antibody levels with serum drug trough levels and therapeutic response of adalimumab and etanercept treatment in rheumatoid arthritis”, Ann Rheum Dis. 2015 Mar; 74 (3).[3]Kalden J. and H. Schulze-Koops, “ Immunogenicity and loss of response to TNF inhibitors: implications for rheumatoid arthritis treatment ”, Nature Reviews Rheumatology, 2017 volume 13, 707–718.[4]Wolf-Henning Boehnck, N. Brembilla, “ Immunogenicity of biological therapies: causes and consequences, ” Expert Review of Clinical Immunology, Vol 14, 2018, Issue 6, 513-523Disclosure of Interests:None declared


2021 ◽  
Vol 14 (6) ◽  
pp. 562
Author(s):  
Mauro Banchero

Cyclodextrins are widely used in pharmaceutics to enhance the bioavailability of many drugs. Conventional drug/cyclodextrin complexation techniques suffer from many drawbacks, such as a high residual content of toxic solvents in the formulations, the degradation of heat labile drugs and the difficulty in controlling the size and morphology of the product particles. These can be overcome by supercritical fluid technology thanks to the outstanding properties of supercritical CO2 (scCO2) such as its mild critical point, its tunable solvent power, and the absence of solvent residue after depressurization. In this work the use of scCO2 as an unconventional medium to achieve the complexation with native and substituted cyclodextrins of over 50 drugs, which belong to different classes, are reviewed. This can be achieved with different approaches such as the “supercritical solvent impregnation” and “particle-formation” techniques. The different techniques are discussed to point out how they affect the complexation mechanism and efficiency, the physical state of the drug as well as the particle size distribution and morphology, which finally condition the release kinetics and drug bioavailability. When applicable, the results obtained for the same drug with various cyclodextrins, or different complexation techniques are compared with those obtained with conventional approaches.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Shanshan Hu ◽  
Xibo Pei ◽  
Lunliang Duan ◽  
Zhou Zhu ◽  
Yanhua Liu ◽  
...  

AbstractAdministration of drugs via the buccal route has attracted much attention in recent years. However, developing systems with satisfactory adhesion under wet conditions and adequate drug bioavailability still remains a challenge. Here, we propose a mussel-inspired mucoadhesive film. Ex vivo models show that this film can achieve strong adhesion to wet buccal tissues (up to 38.72 ± 10.94 kPa). We also demonstrate that the adhesion mechanism of this film relies on both physical association and covalent bonding between the film and mucus. Additionally, the film with incorporated polydopamine nanoparticles shows superior advantages for transport across the mucosal barrier, with improved drug bioavailability (~3.5-fold greater than observed with oral delivery) and therapeutic efficacy in oral mucositis models (~6.0-fold improvement in wound closure at day 5 compared with that observed with no treatment). We anticipate that this platform might aid the development of tissue adhesives and inspire the design of nanoparticle-based buccal delivery systems.


2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
A. Phillip Owens ◽  
Yacine Boulaftali ◽  
Wolfgang Bergmeier ◽  
James P Luyendyk ◽  
Nigel Mackman

Objective Platelets play a central role in both hemostasis and thrombosis. The coagulation protease thrombin activates platelets by cleavage of protease-activated receptors (PAR1 and PAR4 in humans, and PAR3 and PAR4 in mice). Circulating thrombin is increased in patients with abdominal aortic aneurysms (AAAs). We recently demonstrated that PAR4 deficiency in mice increased the incidence of aneurysm (P = 0.001) and rupture-induced death (P = 0.003) in an angiotensin II (AngII) infusion model of AAA. Furthermore, platelet depletion significantly increased rupture in this model (P = 0.048). The purpose of this study was to examine clinically used anti-platelet drugs in this mouse model of AAA. Methods and Results Male Ldlr -/- mice (8-12 weeks in age) were fed a fat and cholesterol-enriched diet (21% milk fat, 0.2% cholesterol). Groups of mice received either aspirin (30 mg/L via drinking water [ASA]), or diet supplemented with the direct thrombin inhibitor dabigatran etexilate (10 g/kg chow [DE]) or the P2Y 12 inhibitor clopidogrel (50 mg/kg/day [Plavix]) 1 week prior to and throughout AngII (1,000 ng/kg/min) infusion for 28 days. Drug bioavailability was confirmed with all treatments. Medial diameters in the suprarenal aortic region were increased significantly from baseline to day 28 in all groups infused with AngII, as measured by in vivo ultrasound. Medial diameters were not different in any of the treatment groups compared with placebo controls. However, DE (87% vs. 47%) and Plavix (82% vs. 40%) significantly increased the incidence of AAA versus placebo groups (P < 0.05). ASA also increased the incidence of AAA (93% vs. 70% P = NS). Importantly, all treatments had a significant increase in aortic rupture-induced death versus placebo groups (P < 0.05; DE [67% vs. 7%]; Plavix [41% vs. 0%]; and ASA [64% vs. 10%]). None of the treatments affected total plasma cholesterol, lipoprotein-cholesterol distributions, or AngII-induced increases in systolic blood pressure. Conclusion This study indicates that the presence of functional platelets reduces the formation and rupture of AAA in this mouse model. This suggests that inhibition of platelet function may be detrimental to patients with existing AAAs, a conclusion that will be addressed in future mouse studies.


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