Release Of Tetracycline Research Articles

Plga Microspheres as a Delivery Vehicle for Sustained Release of Tetracycline: Biodistribution in Mice After Subcutaneous Administration

This study was designed to investigate the preparation, in vitro release, in vivo pharmacokinetics and tissue distribution of tetracycline-loaded microspheres. Tetracycline-loaded microspheres composed of PLGA were prepared by a spray drying method. The prepared microspheres were characterized according to drug loading, size and shape. The in vitro release profiles indicate that the release of tetracycline from the microspheres exhibits sustained release behavior. The results obtained from tissue distribution study by subcutaneous administration were also consistent with the results of in vitro release. After the burst release, the drug release rate was greatly reduced at the administration site, with the whole in vivo release continuing for 21 days. No tetracycline in blood, liver or kidney could be detected after 4 hours. Based on these research data, tetracycline-loaded PLGA microspheres were capable of releasing tetracycline in a controlled way, thereby constantly providing an appropriate drug level at the administration site.

Laponite clay as a carrier for in situ delivery of tetracycline

Although smectite clays have gained much interest in recent years as potential sustained local drug delivery vehicles, they have not been yet utilized or assessed as a local drug delivery device for treatment of periodontal disease. In this paper we showed that unique nanostructure and gel-formation ability of clay holds great promise as an effective drug carrier. In particular, we demonstrated the feasibility of using laponite XLG, a smectite clay, as a carrier for in situ delivery of tetracycline that can potentially be used in the treatment and prevention of periodontal disease. The intercalation of tetracycline between the layers of laponite at different acidic pHs and different concentrations of tetracycline was examined. The laponite–tetracycline composite was characterized using X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR) and differential thermal analysis (DTA). The results showed that, in a pH and concentration dependent manner, tetracycline can be intercalated between the layers of laponite nanoparticles. The release study in a simulated saliva solution demonstrated a sustained release of tetracycline from laponite over a 72 hour period. The antimicrobial activity of the released tetracycline was maintained and was not affected by the intercalation of tetracycline into the carrier (laponite) and its release from the carrier.

Kinetics of drug release from a biodegradable local drug delivery system and its effect on Porphyromonas gingivalis isolates: An in vitro study.

Background:Conventional anti-microbial therapy largely consisted of systemic administration of various drugs effective against periodontal pathogens, but fraught with several problems. Based on the concept of local drug delivery a bioresorbable device made of pure fibrillar collagen has been developed. The aim of this study was to study the release of Tetracycline from this collagen fiber (Type I collagen) impregnated with Tetracycline and its antibacterial activity against Porphyromonas gingivalis.Materials and Methods:Porphyromonas gingivalis was isolated from plaque samples of chronic periodontitis patients by using a CO2 incubator. DNA isolation was done followed by polymerase chain reaction (PCR) amplification to confirm the presence of bacteria. The release pattern of Tetracycline was assessed for a period of 10 days in water (group I) and Serum inoculated with Porphyromonas gingivalis (group II).Results:A significant presence of Tetracycline on all days in Group I and group II and the zone of inhibition was also present in both groups with a steady decline from day 1 to day 10.Conclusion:Since the results were well within the therapeutic concentration of drug required to inhibit the growth of gram –ve bacteria (Porphyromonas gingivalis), this bioresorbable Tetracycline fiber has the potential for clinical application.

Electrospun matrices for localised controlled drug delivery: release of tetracycline hydrochloride from layers of polycaprolactone and poly(ethylene-co-vinyl acetate).

We report the controlled release of tetracycline (Tet) HCl from a three-layered electrospun matrix for the first time. Five formulations of electrospun poly-ε-caprolactone (PCL) and poly(ethylene-co-vinyl acetate) (PEVA) have been designed, prepared as micro/nanofibre layers, and assayed for the controlled release of the clinically useful antibiotic Tet HCl with potential applications in wound healing and especially in complicated skin and skin-structure infections. Tet HCl was also chosen as a model drug possessing a good ultraviolet (UV) chromophore and capable of fluorescence together with limited stability. Tet HCl was successfully incorporated (essentially quantitatively at 3%, w/w) and provided controlled release from multilayered electrospun matrices. The Tet HCl release test was carried out by a total immersion method on 2 × 2cm(2) electrospun fibrous mats in Tris or phosphate-buffered saline heated to 37°C. The formulation PCL/PEVA/PCL with Tet HCl in each layer gave a large initial (burst) release followed by a sustained release. Adding a third layer to the two-layered formulations led to release being sustained from 6days to more than 15days. There was no detectable loss of Tet chemical stability (as shown by UV and NMR) or bioactivity (as shown by a modified Kirby-Bauer disc assay). Using Tet HCl-sensitive bacteria, Staphylococcus aureus (ATCC 25923), the Tet HCl-loaded three-layered matrix formulations were still showing significantly higher antibacterial effects on days4 and 5 than commercially available Antimicrobial Susceptibility Test Discs of Tet HCl. Electrospinning provides good encapsulation efficiency of Tet HCl within PCL/PEVA/PCL polymers in micro/nanofibre layers which display sustained antibiotic release.

The influence of operating parameters on the drug release and anti-bacterial performances of alginate wound dressings prepared by three-dimensional plotting

Three-dimensional plotting was used to manufacture fibrous alginate hydrogel wound dressings. Samples manufactured using varied operating parameters (increased air pressure, nozzle diameter, and layer increment or decreased calcium concentration, alginate concentration, and speed of the nozzle in the x and y directions) were compared to the control samples. The changes in the fiber size, porosity, tensile properties, degradation, swelling ratio, tetracycline release efficacy, water vapor transmission rate (WVTR), and bacterial inhibition potential due to alterations of the operating parameters were measured. The samples manufactured using altered operating parameters had larger fiber sizes and were less porous than the controls (p<0.05). A significantly higher Young's modulus, a larger ultimate tensile strength, less degradation, and lower swelling ratios were also found among some of the altered samples (p<0.05). The tetracycline release efficacies and bacterial inhibition potentials of the altered samples were not found to be significantly different from those of the controls. The WVTRs of most samples were slightly lower than those of common commercial dressings. When compared to films, the fibrous samples were able to absorb liquid faster and were less stiff, allowing for better conformation to the contours of the wounds. The fibrous samples also provided more sustained tetracycline release.

Preparation and utilization of microporous molecularly imprinted polymer for sustained release of tetracycline

AbstractA polyacrylate tetracycline (TC) selective microporous molecularly imprinted polymer was prepared in three different porogenic solvents (chloroform, acetonitrile, and methanol) via precipitation polymerization, using methacrylic acid monomer, ethylene glycol dimethacrylate crosslinker, and TC as template. In all three solvents this method produced microporous particles in the scale range (200–400 nm), simply, quickly, cleanly, and in good yield. The effect of polarity of porogenic solvents on binding capacity was investigated. The imprinted polymer prepared in chloroform gave much higher binding capacity (KD = 198.6) for TC than the polymers prepared in acetonitrile (KD = 133.2) or methanol (KD = 104.7). The selectivity of imprinted polymers was evaluated by rebinding other structurally similar compounds. The results clearly indicated that the imprinted acrylate polymer exhibits an excellent selectivity toward TC, and has better ability to control the release of TC than the non‐imprinted polymer.© 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Enhanced Loading and Controlled Release of Antibiotics Using Nucleic Acids As an Antibiotic-Binding Effector in Hydrogels

Antibiotic delivery is important to treat bacterial infections, one of the most challenging health problems globally. This study explored the application of nucleic acids as an antibiotic-binding effector for antibiotic loading and release. The data showed that the partition coefficient of tetracycline increased proportionally to the oligonucleotide concentration ranging from 0 to 1 mM. Resultantly, the incorporation of the oligonucleotides led to enhanced tetracycline loading in the hydrogels. In addition to the enhanced drug loading, the oligonucleotides could slow the release of tetracycline from the hydrogels. Experiments were further carried out to examine the capability of oligonucleotide-functionalized hydrogels in the inhibition of bacterial growth. The results showed that the oligonucleotide-functionalized hydrogels had higher antibacterial efficiency. Moreover, after tetracycline release, the oligonucleotide-functionalized hydrogels could be refilled with fresh tetracycline to reproduce the capability of inhibiting bacterial growth. Therefore, nucleic acid oligonucleotides are a promising antibiotic-binding effector for hydrogel functionalization in antibiotic delivery.

The Effects of Lactidyl/Glycolidyl Ratio and Molecular Weight of Poly(D,L -Lactide-co-Glycolide) on the Tetracycline Entrapment and Release Kinetics of Drug-Loaded Nanofibers

Electrospun tetracycline (Tet)-loaded poly(D,L-lactide-co-glycolide) (PLGA) nanofibers are considered to have great potential as local drug-delivery systems. This study was designed to explore the effects of the lactidyl/glycolidyl (LA/GA) unit ratio and molecular weight of PLGA on Tet entrapment efficiency and in vitro release kinetics. Three kinds of PLGA (PLGA75/25, M w = 100 000 or 50 000; PLGA50/50, M w = 50 000) were examined in this study. Electrospun nanofibers were fabricated containing 3, 5, 10 wt% Tet. The results showed that PLGA50/50 entrapped more Tet than both PLGA75/25 co-polymers, and the PLGA75/25 of M w = 100 000 entrapped the least amount of Tet, suggesting that the lower the molecular weight of PLGA was, the higher the GA content in PLGA was and the higher the resulting Tet entrapment. Tet loading played an important role in Tet release. Nanofibers with 3 and 5 wt% Tet loading exhibited a sustained release for more than 28 days, whereas 10 wt% Tet only lasted 14 days. Loading of 3 wt% Tet resulted in approx. 35% release in the initial 12 h, 5 wt% Tet released approx. 70% and 10 wt% Tet resulted in approx. 85% release. The integrity of Tet incorporated into electrospun PLGA nanofibers was identified by FT-IR spectrum examination and the bacterial inhibition test. The modified Kirby–Bauer test showed dose-dependent inhibition of Staphylococcus aureus growth by Tet, confirming Tet structural stability throughout the electrospinning procedure. MG-63 cells demonstrated good adhesion and proliferation on all PLGA/Tet fibrous membranes. These results indicate that Tet entrapment and release kinetics of PLGA/Tet composite fibrous scaffolds can be tailored by the LA/GA ratios, molecular weights and drug loadings. Tet-loaded fibrous scaffolds show great potential for local drug delivery and bone defect repair.

Effect of zein on biodegradable inserts for the delivery of tetracycline within periodontal pockets

Treatment with antibiotics within the periodontal pocket against bacterial infections represents a useful and adjunctive tool to conventional therapy for healing and teeth preservation. With this function in view, an implantable, tetracycline delivery device for the treatment of periodontal disease was developed. The aim of this study was to develop biodegradable, tetracycline-loaded microparticles made of two polymers: PLGA and zein which were compressed into monolithic devices. In this polymer delivery system, the encapsulation efficiency, release characteristics, drug-polymer interaction, and antibacterial activity of loaded drug were investigated. The interaction of tetracycline with the corn protein zein was studied by nuclear magnetic resonance (NMR), Fourier transform infrared, and X-ray diffraction. The hydrophobic interaction of tetracycline with zein in the formulations was deduced from the NMR studies, whereas X-ray diffraction studies showed a new crystalline state of the drug in the presence of the protein. Zein was not denatured by preparation of inserts. Sustained release of tetracycline was obtained, and the proportion of zein in the inserts had a great impact on the drug release. Finally, an effective tetracycline release from inserts against Staphylococcus aureus was achieved over 30 days. In conclusion, the PLGA:zein delivery system described in this study was found to be effective in controlled delivery of tetracycline, and hence may be suitable for intra-pocket delivery of antimicrobial agents in the treatment of periodontitis.

Controlled Release of Tetracycline–HCl from Halloysite–Polymer Composite Films

The first direct comparison between two common methods for loading halloysite with a small molecule for controlled release is presented. While the methods differ in the degree of simplicity, they provide essentially the same level of loading and release kinetics. A tentative explanation of the "burst" effect often seen in the release of low molecular weight molecules from halloysite is provided. The ability of halloysite to mediate the release rate of a water soluble drug, tetracycline, from solution cast polyvinyl alcohol and polymethyl methacrylate films was evaluated. In some films, montmorillonite was also incorporated. The addition of montmorillonite to solutions used to cast tetracycline containing films significantly reduced the release rate from the dried films. The same overall effect was seen when the drug was loaded into halloysite prior to preparation of the films. In both cases, the release was best fit with the simple Higuchi model. However, when montmorillonite was added to solutions of polyvinyl alcohol and drug loaded halloysite the release profiles were better fit by the Ritgar-Peppas model for anomalous transport. Release from polymethyl methacrylate was reduced by a factor of three by incorporating the drug in halloysite prior to producing the films.

Release of tetracycline from O-carboxymethylchitosan films

O-carboxymethylchitosan films containing tetracycline were prepared by the casting method. The films were hardened by reaction with glutaraldehyde-induced crosslinking and heat treatment at 90°C, 120°C and 150°C. The effect, on the films, of hardening methods, water uptake, moisture, drug release and antimicrobial activity against Staphylococcus aureus was evaluated. The O-carboxymethylchitosan films were soluble in simulated saliva and after treatment, and the water uptake of the films decreased as the temperature or presence of glutaraldehyde increased. The antimicrobial activity of tetracycline was preserved, and efficiency was dependent on the hardening treatment to which the films were submitted.

Sustained release of tetracycline from polymeric periodontal inserts prepared by extrusion

AbstractThe specific aim of this study was to prepare polymeric inserts containing tetracycline that are intended for intraperiodontal pocket application. The inserts were prepared by a simple extrusion method and based on mixtures of polyvinyl alcohol, glyceryl behenate, xanthan gum, carrageenan, hydroxypropyl methylcellulose, and hyaluronic acid in addition to tetracycline HCL. The inserts were characterized regarding average weight, diameter, water content, and average tetracycline content. Zero‐order release kinetics of tetracycline were observed in case of three of the four batches of the prepared inserts with release profiles that were essentially similar. The release of the drug was incomplete in all cases. This was due, as shown by the equilibrium dialysis tests, to tetracycline binding by the polymers. However, the inserts performed more than 7 days drug sustained release which indicates promising results for local delivery of tetracycline for treatment of periodontal disease. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

Controlled release of tetracycline from biodegradable β‐tricalcium phosphate composites

For use in the prevention of bone infections, a novel controlled release system composed of beta-tricalcium phosphate (TCP) granules with biodegradable coatings incorporating the antibiotic drug tetracycline (TC) was developed. Six formulations using poly(D,L-lactide) and poly(D,L-lactide-co-glycolide) as coating materials to incorporate TC were prepared and tested in vitro and in vivo. Release of TC from TCP composites was dependent on the biodegradability of the used polymers and on physical-chemical interactions of TC with the polymer materials. Three characteristic release profiles were obtained: slow release lasting up to 67 days, intermediate release with 60% of the total dose released up to day 20, and fast release with a high initial burst and 90% of TC released within 4 days. Even though TC decomposition products had formed during in vitro release, no cytotoxic effects on osteoblast-like cells were observed. The biological activity of TC after incorporation into PL(G)A films was confirmed using a TC-repressible promoter system in genetically engineered Chinese Hamster Ovary (CHO) cells. TC-loaded TCP composites implanted in ovine cancellous bone defects showed good biocompatibility and new bone formation in the histological evaluation. No differences in the cellular reactions were seen between antibiotic-loaded composites and the control group. These experimental results indicate the potential of coated TCP composites to be used as local carrier system for controlled TC delivery with different release kinetics and good in vitro and in vivo biocompatibility.

Sustained and localized in vitro release of BMP‐2/7, RANKL, and tetracycline from Flexbone, an elastomeric osteoconductive bone substitute

We tested the hypothesis that synthetic composites containing a high percentage of osteoconductive biominerals well-integrated with a hydrophilic polymer matrix can be engineered to provide both the structural and biochemical framework of a viable synthetic bone substitute. FlexBone, an elastic hydrogel-mineral composite exhibiting excellent structural integration was prepared by crosslinking poly(2-hydroxyethyl methacrylate) hydrogel in the presence of 25 wt% nanocrystalline hydroxyapatite and 25 wt% tricalcium phosphate. Biologically active factors tetracycline, BMP-2/7, and RANKL that stimulate bone formation and remodeling were encapsulated into FlexBone during polymerization or via postpolymerization adsorption. SEM and dynamic mechanical analyses showed that the encapsulation of tetracycline (5.0 wt%) did not compromise the structural integrity and compressive behavior of FlexBone, which could withstand repetitive megapascal-compressive loadings and be securely press-fitted into critical femoral defects. Dose-dependent, sustained in vitro release of tetracycline was characterized by spectroscopy and bacterial inhibition. A single dose of 40 ng BMP-2/7 or 10 ng RANKL pre-encapsulated with 50 mg FlexBone, released over 1 week, was able to induce local osteogenic differentiation of myoblast C2C12 cells and osteoclastogenesis of macrophage RAW264.7 cells, respectively. With a bonelike structural composition, useful surgical handling characteristics, and tunable biochemical microenvironment, FlexBone provides an exciting opportunity for the treatment of hard-to-heal skeletal defects with minimal systemic side effects.

In vitro cytotoxicity of a novel injectable and biodegradable alveolar bone substitute

The unsaturated polyphosphoester (UPPE) polymer is being investigated as an injectable and biodegradable system for alveolar bone repair in the treatment of periodontal diseases. The incorporation of β-tricalcium phosphate (β-TCP) particles into the UPPE polymer was previously shown to significantly increase the material’s mechanical properties. Moreover, in vitro experiments demonstrated that the UPPE/β-TCP composite was capable of zero-order release of tetracycline for over 2 weeks. In this study, we investigated the in vitro cytotoxicity of each individual component, the resulting cross-linked network and the degradation products of the UPPE/β-TCP composite using an AlamarBlue viability assay. We confirmed that each individual component except β-TCP and the in vitro degradation products of the composite displayed a dose-dependent cytotoxic response. Once cross-linked, however, the composite did not demonstrate an adverse response. Our results suggest that the UPPE/β-TCP composite holds great promise for use as an injectable and biodegradable alveolar bone substitute.

Tetracycline release from tripolyphosphate–chitosan cross‐linked sponge: a preliminary in vitro study

The aim of this study was to design a tripolyphosphate-chitosan cross-linked tetracycline-containing (TPP-TC) sponge that slowly releases tetracycline, for future periodontal applications. Chitosan sponge was made by freezing and drying 2.5% chitosan solution. Tripolyphosphate-chitosan cross-linked (TPP) sponge was made by immersing the chitosan sponge in tripolyphosphate solution and air drying it. Tetracycline-containing chitosan (TC) sponge was prepared by freezing and drying a mixture of chitosan and tetracycline. TPP-TC sponge was made by immersing the TC sponge in tripolyphosphate solution. The weight, thickness and diameter of the four chitosan sponges were recorded. Their surface microstructures were inspected using scanning electron microscopy. The amount of tetracycline released from the sponges was analyzed by spectrophotometry. Antimicrobial activities of the residual sponges were tested against Staphylococcus aureus and Escherichia coli. The topography of the scaffolds was intact after the addition of tetracycline. However, increased surface irregularities were noted. In sponges with tripolyphosphate, intensified surface folding was observed. The weight of the sponges increased after tripolyphosphate and tetracycline were added, but their thicknesses and diameters decreased after cross-linking. Tetracycline was detected in the solution containing TPP-TC sponges until day 11. On day 7, the tetracycline released from TC sponges was less than that released from TPP-TC sponges. Bacterial growth was inhibited by sponges containing tetracycline. The inhibitory effect of the TPP-TC sponges was detectable until day 11. Our data showed that TPP-TC sponge was suitable as a slow-release device for tetracycline and that it maintained antimicrobial effects against the bacteria tested for up to 11 d.

Slow Release of Tetracycline from a Mucoadhesive Complex with Sucralfate for Eradication of Helicobacter pylori

Treatment composed of a gastric mucoadhesive antibiotic with slow release drug delivery is expected to be effective for the eradication of Helicobacter pylori (H. pylori). In this study, we evaluated the slow release property of the tetracycline-sucralfate acidic complex. Tetracycline was the antibiotic selected because of its complexation capacity with sucralfate. Sustained release was tested using two different dissolution test methods: paddle and flow-through cell. The adhesive paste formed from the acidic complex displayed a longer sustained release profile of tetracycline using flow-through cell method. The milder conditions of the flow-through cell method better mimicked the fasted state of the stomach, suggesting that the oral administration with fasting is appropriate for the acidic complex. Furthermore, the paste formation protected the tetracycline from decomposition under an acidic condition, which apparently contributes to long-term release. Change in the zeta potential of the acidic complex particles was helpful in clarifying the release mechanisms of the tetracycline. The data indicated that the immediate release of tetracycline in the early stage of the test was indispensable to the subsequent paste formation that enables slow release. If administrated orally with fasting, the acidic complex rapidly adheres to the gastric mucosa and sustains long-term release of the tetracycline to the gastric lumen or mucus layer. This antibiotic delivery mechanism, which requires only a minimum dosage, may be effective for efficient eradication of H. pylori.

Polymeric electro-mechanic devices applied to antibiotic-controlled release

Polymeric electroactive blends formed by electropolymerized aniline inside a non-conductive polyacrylamide porous matrix were already shown as suitable materials for the electrocontrolled release of model compounds like safranin. In this paper the intermolecular interactions between the two components of the blend are put in evidence by Raman spectroscopy measurements. Also, in situ optical microscopy was used to follow changes occurring in the polyaniline/polyacrylamide blend during pyrocathecol violet release tests. These two sets of experiments show the possibility of controlling electrochemically the release of both, safranin (a cation) and pyrocathecol violet (an anion) and allow to infer a release mechanism based on the electromechanical properties of the blends explaining the dependence of the release kinetics on the applied potential. Tetracycline release curves for different potentials and pHs are shown and the obtained profiles are in agreement with those expected for a device acting as an electrochemically driven pump due to the artificial muscle properties of the conducting phase of the blends.

Study of controlled tetracycline release from porous calcium phosphate/polyhydroxybutyrate composites

AbstractPorous calcium phosphate ceramics were prepared by sintering of mixtures of nanocrystalline apatitic calcium phosphate and fibrous natural cotton cellulose after pressing at temperatures of 1150 °C and 1250 °C. Micro-and macropores were present in microstructures of ceramic samples. The microstructures of porous ceramics were similar to those observed in bone tissues and fiber-like randomly oriented texture was observed in ceramics. Polyhydroxybutyrate (PHB) biopolymer layers are distributed homogeneously in the samples after evaporation of the diluent (chloroform) from the PHB vacuum impregnated porous samples. The tetracycline (TTC) release rate decreases with the content of polyhydroxybutyrate in the ceramic samples, which corresponds to the rise in amount of biopolymer displaced in the pores of ceramics. The concentration of TTC in the phosphate buffer saline solution varies almost linearly with time after the first seven hours from the start of the release of the calcium phosphate ceramic samples with 2.4 mass % of polyhydroxybutyrate. The initial burst effect was significantly depressed by the preparation method used.

Behaviour and fate of tetracycline in river and wetland waters on the Canadian Northern Great Plains

Very little is known about the factors affecting the behaviour, degradation and persistence of tetracycline in sensitive Prairie freshwater aquatic systems in Canada. Reported are results of studies conducted for the first time of tetracycline behaviour in Prairie river and wetland waters. For comparison, studies were also conducted using distilled water as a control. Different amounts of spiked tetracycline (0, 50 and 80 percent) was adsorbed by distilled, river and wetland water, respectively. These different amounts are likely due to the differences in the matrixes of the three waters. In wetland water, the addition of EDTA generally promoted the release of tetracycline indicating that a portion of the tetracycline was bound to metal ions. Decreasing the pH of the wetland water led to increased adsorption of tetracycline suggesting either that tetracycline epimerizes or binds, by hydrogen bonding, to acidic portions of organic material in the water. However, in wetland water, a significant portion of the spiked tetracycline (≅ 50%) was irreversibly bound to the water matrix and was not released by adding EDTA and/or by varying the pH. In laboratory experiments, the t1/2 of “free-form” tetracycline exposed to light (L+) in non-sterile waters was 32, 2 and 3 days in distilled, river and wetland water respectively, while in waters with no light exposure (L−), they were 83, 18 and 13 days. Similarly, t1/2 of tetracycline in L+ sterile waters treatments was 9, 1 and 1 day for distilled, river and wetland water, respectively, and 18, 11 and 7 days in the L−. In the experiment conducted in natural sunlight, tetracycline t1/2 in the presence of ultraviolet radiation (UV) treatments was 26, 17 and 18 min in distilled, river and wetland water and 39, 28 and 32 min in the absence of UV treatment. The combination of the effects of matrixes of the water, light and UV radiation therefore play a significant role in catalyzing the removal of tetracycline from different Prairie waters. In deep waters and in systems where sunlight is highly attenuated, the effects of light on tetracycline may be considerably reduced.