Preparation and in vitro evaluation of a novel chitosan-based hydrogel for injectable delivery of enrofloxacin

Background: the development of injectable sustained- release products are of great interest to veterinary pharmaceuticals and animal health business. Recently, great attention has been paid to in situ gel-forming chitosan/ beta-glycerophosphate [chitosan/beta-GP] solutions due to their good biodegradability and thermosensitivity

Objectives: the general aim of this study was to prepare a novel in situ gel-forming drug delivery system with a sustained release profile for enrofloxacin

Methods: chitosan, beta-GP and enrofloxacin were used in different concentrations and six formulations of chitosan/beta-GP were prepared. The properties of the hydrogels including the pattern of drug release, gelation time, syringeability, morphology, FTIR spectra, and in vitro antimicrobial activity were evaluated

Results: the release rate of enrofloxacin from the hydrogels and syringeability of the final solutions were decreased by increasing in beta-GP and chitosan concentrations. All formulations could release the drug up to 120 hours but formulation 1 [chitosan-2%, beta-GP-5% and enrofloxacin-1%] gave the best results based on its optimal drug release profile and viscosity. The FTIR studies showed that there were no interactions between enrofloxacin and hydrogel excipients. Scanning electron microscopy showed that the formed gel had a continuous texture, while the swelled gel in phosphate buffer had a porous structure. Microbiological tests revealed high bactericidal activities for this enrofloxacin- loaded hydrogel which were comparable to those of positive control [enrofloxacin suspension] in terms of inhibition zone, MIC and MBC values

Conclusions: because of simple preparation and sustained release profile of the drug, this hydrogel could be a promising delivery system for enrofloxacin in animals

survey on antibacterial drug use in broiler chicken farms in Qum province, Iran

Background: Antibacterial drugs have long been used for prevention and treatment of poultry diseases but their misuse or overuse can make adverse effects on public health including occurrence of drug residues in poultry products

Objectives: To assess the frequency and status of antibacterial drug consumption in broiler production farms in Qum province

Methods: In the present survey, Qum province was divided into six regions [north, west, southwest, south, southeast and east] and in total 138 broiler production units [59%] were studied by direct interview using a questionnaire

Results: The present study showed that the most frequently used antimicrobial drugs in broiler farms were sulfamethoxazole+trimethoprim [93.4%] followed by enrofloxacin [60.0%], colistin [49.7%], furazolidone [42.0%], oxytetracycline [17.5%], and chloramphenicol [14.6%]. Mean antibacterial consumption rate during a 42-48 day production period was 3.0+/-0.37 times per farm. A notable finding in this survey was the high percentage of banned drug usage such as furazolidone and chloramphenicol, indicating the ignorance or un-awareness of poultrymen regarding the potential hazards of these drugs on public health

Conclusions: Owing to widespread and frequent usage of antibacterial drugs in broiler farms, all-out actions are needed to be taken in educational, research and administrative fields of veterinary and animal production sectors for rational and responsible use of these drugs in poultry industry

Preparation and evaluation of a thermosensitive liposomal hydrogel for sustained delivery of danofloxacin using mesoporous silica nanoparticles

Background: sustained release delivery system can reduce the dosage frequency and maintain the therapeutic level of drugs for a longer time. Biodegradable, biocompatible and thermosensitive chitosan-beta-glycerophosphate [C-GP] solutions can solidify at body temperature and maintain their physical integrity for a longer duration

Objectives: to develop a novel delivery system based on the integration of liposomes in hydrogel using mesoporous silica nanoparticles [MSNs] for sustained release of danofloxacin in farm animals

Methods: the MSNs were prepared using N-cetyltrimethylammonium bromide and tetraethylortho silica. The liposomes were prepared by thin film hydration method. C-GP solution containing danofloxacin-loaded MSN liposomes underwent different in-vitro tests, including evaluation of the entrapment efficiency, gelation time, morphology, drug release pattern as well as antimicrobial activities against S. aureus and E. coli

Results: the mean pore size of MSNs was 2.8 nm and the mean MSN entrapment efficiency was 45%. Kinetics of danofloxacin release from liposomal hydrogel followed the Higuchi's model. This formulation was capable of sustaining the danofloxacin release for more than 96 h. The FTIR studies showed that there were no interactions between danofloxacin and hydrogel excipients. Scanning electron microscopy [SEM] showed that the formed gel had a continuous texture, while the swelled gel in the phosphate buffer had a porous structure. Microbiological tests revealed a high antibacterial activity for lipomosal hydrogel of danofloxacin-loaded MSN comparable with danofloxacin solution

Conclusions: the liposomal hydrogel solidified at body temperature, effectively sustained the release of danofloxacin and showed in vitro antibacterial effects

[Bone protective effects following ethanolic extract [Otostegia persica] administration in streptozotocin-induced diabetic rats: histomorphometric study]

Background: Medical plants have been recently used to treat diabetes. Osteoporosis is one of diabetes side effects and increases the risk of bone fracture in diabetic patient

Objectives: The purpose of the present study was to investigate the potential bone protective effects of O.persica ethanolic extract in streptozotocin-induced diabetic rats

Methods: Forty male rats were randomly divided into five equal groups and treated as follows: group 1 [control]; group 2 [STZ group]: received STZ 50 mg/kg by a single IP injection; groups 3, 4 and 5 treated with STZ as above+ 200 mg/kg, 300 mg/kg and 450 mg/kg of O. persica extract per day by oral gavage, respectively. On day 29, serum taken for glucose level measurement and left femoral and tibio-fibular bones were dissected for histomorphometric study, while L4 vertebrate were removed for determination of ash weight

Results: 300mg/kg of extract reduced serum glucose levels. Epiphyseal and metaphyseal Trabecular thickness as well as epiphyseal bone area/tissue area significantly decreased in STZ group. O. persica extract at the dosage of 200 mg/kg reversed all these parameters to the control level. No significant difference observed in osteoid thickness among different groups. Ash weight of L4 vertebrate in rats treated with 300 and 450 mg/kg of extract was significantly lower than other groups

Conclusions:The results show that ethanolic extract of O. persica has bone protective effects in STZ-treated rats

survey on antibacterial drug usage in dairy farms in Tehran province during 2004-2005

Antibacterial drug use in food-producing animals may be associated with risks to public health. The present survey was carried out due to lack of data on the status of antibacterial drug usage in Tehran Province dairy farms. The purpose of the present study was to investigate the status of antibacterial drug usage in these farms and implementation of the points from public health view. A total of 120 dairy farms in four regions of Tehran province including East [Damavand], South-East [Varamin and Shar-e-Rey], South-West [Shariar and Islamshar] and West [Karaj and Savojbolagh], were surveyed by direct interview using a questionnaire. The mean consumption rate of oxytetracycline and penicillin + streptomycin, 100% and 93.25%, respectively, were the most frequently used antibacterial products in these dairy farms in terms of variety, and a wide range of other antibacterials also showed high percentages of usage. Regarding intramammary formulations, cloxacillin, Dry Cow [DC], with a mean of 82.5%, was shown to be the most frequently used intramammary products in terms of variety. In 47.4% of farms, the orders for antibacterial drugs were issued by non-veterinarians. Also, in a considerable percentage of dairy farms the milk collected from animals receiving antibacterial drugs for mastitis [27.5%] or other infectious diseases [24.2%] were being entered into the milk reservoirs to be used for humans. The principles of rational antimicrobial therapy as well as withdrawal/ milk discard times are not implemented in a great percentage of these dairy farms. This situation may be due to lack of knowledge among dairymen regarding drug use and public health, and inadequate supervision of the veterinary offices of Tehran province

trace analysis of oxytetracycline and tetracycline residues in pasteurized milk supplied in Tehran: a one-year study [April 2011-March 2012]

Tetracyclines [TCs] are broad-spectrum antibiotics that are widely used in veterinary medicine. The presence of TCs residues in milk is a public health concern all over the world. This study aimed to determine TCs residuals in pasteurized milk marketed by some dairy companies in Tehran from April 2011 to March 2012. 432 pasteurized milk samples were purchased from supermarkets supplying the milk products of 12 major dairy companies in Tehran [3 samples from each company every month], and they were stored at -20 0C until analysis. Oxytetracycline [OTC] and Tetracycline [TC] residues in each sample were extracted by a liquid - liquid phase procedure and quantitated using a high performance liquid chromatographic [HPLC] method. Chromatographic conditions included a mobile phase as oxalic acid buffer- acetonitril [80: 20] with a flow rate of 1mL/min and UVdetection at 355 nm. TCs residuals in most milk samples were lower than 100 ppb, maximum residue level [MRL]; however, in seven samples [1.62%] the total residues of OTC and TC were more than MRL. In the latter milk samples, the median total TCs residue was 625 ppb, ranging between 274 and 1270 ppb. Because of the presence of TC residues above the MRL level in a limited number of milk samples, it is concluded that more studies and supervision of health authorities are needed in this field

Abioequivalence study on two closantel oral suspensions in sheep: an Iranian product [fascinil[registered sign]] versus flukiver[registered sign] as a reference product

Closantel is a broad-spectrum antiparasitic agent and is widely used for the control of Fasciola spp. and Haemonchus spp. infestations in sheep and cattle. The present study was carried out to evaluate the bioequivalence of a domestic closantel formulation, Fascinil[registered sign] [Damloran Pharmaceutical Co., Iran], in comparison with Flukiver[registered sign] [Janssen pharmaceutical Co., Belgium] in sheep. In a parallel design, twenty-eight male sheep, 4- 5 months of age, were randomly divided into two groups. First group received a single dose of Fascinil[registered sign] oral suspension as a test product at 10 mg/kg BW, and the second group received Flukiver[registered sign] as a reference product with the same dose. Blood samples were taken on 0, 4, 8, 12, 16, 20, 24, 32, 48, and 72 hours after drug administration, and the plasma concentrations of closantel were determined using a high performance liquid chromatographic [HPLC] method. Pharmacokinetic analysis was performed; in addition, the areas under the plasma concentration-time curves at 0-72h [AUC0-72], maximum plasma concentrations [Cmax], and times to reach Cmax [Tmax] of the closantel in test and reference groups were compared. There were no significant differences in the AUC0-72 [2913.00 +/- 648.18, 2957.88 +/- 623.41 micro g.h/mL], Cmax [62.22 +/- 7.74, 71.71 +/- 13.03micro g /mL], and Tmax [23.38 +/- 4.27, 23.23 +/- 4.28h] between Fascinil[registered sign] and Flukiver[registered sign], respectively. The 90% confidence intervals for test: reference ratios of these pharmacokinetic [PK] parameters were within bioequivalence acceptable range [80-120%]. It is concluded that the test product [Fascinil[registered sign]] and Flukiver[registered sign] are bioequivalent, and they can be used as interchangeable anthelmintic drugs

Effects of Fig tree [Ficus carica] leaf extracts on serum and liver cholesterol levels in hyperlipidemic rats

The effects of three Ficus carica leaf extracts on the total cholesterol levels [TC] of serum and liver were investigated in experimentally-induced nutritional hyperlipidemic rats. In nine treatment groups [n=5 each group], hyperlipidemic rats were treated daily with hydromethanolic [total] extract [2.5, 5, 10 mg/kg, intraperitoneal [ip]] and its aqueous fractions, namely fraction A [10, 50,250 mg/kg, ip] and fraction B [10, 50,250 mg/kg, ip] for eight days. In negative and positive control groups, animals received normal and hyperlipidemic diets with ip injections of normal saline, respectively. The lipid-lowering effect of total extract on liver cholesterol was more pronounced than that of serum. Fraction A caused a significant dose-dependent decrease in cholesterol levels in both the serum and the liver [p<0.05]. Fraction A at dosages of 10, 50 and 250 mg/kg lowered the TC in serum from 1.40 +/- 0.26 mmol/L [mean +/- standard deviation; untreated hyperlipidemic group] to 1.06 +/- 0.14, 1.04 +/- 0.07 and 0.90 +/- 0.08 mmol/L, respectively. At 50 and 250 mg/kg, it lowered the TC in liver significantly from 59.86 +/- 10.35 mg/g [untreated] to 42.61 +/- 12.08 and 37.16 +/- 5.59 mg/g, respectively. Fraction B lowered the level of TC in the serum and liver, but the results of this treatment were conflicting. Phytochemical screening showed that total extract had moderate levels of flavonoids and a large amount of tannins, which may account for the observed effects on decreasing TC levels. In conclusion, Ficus carica leaf extracts have been shown to decrease liver and serum TC levels in hyperlipidemic rats

Correlation between lipid-lowering and bone-protective effects of eicosapentaenoic acid in rats with steroid induced bone loss

This study was conducted to investigate the correlation between lipid-lowering and bone-protective effects of eicosapentaenoic acid on steroid-induced bone changes in rats. Twenty-one male 10-week-old Wistar rats were divided into 3 groups [n = 7 each] and treated with 0.9% NaCl SC [group 1] or methylprednisolone 7 mg/kg SC once a week [group 2] or methylprednisolone 7 mg/kg SC once a week + eicosapentaenoic acid 160 mg/kg, PO daily [group 3], for 6 weeks. At the end of the experiment, serum total cholesterol and triglycerides concentrations were determined using enzymatic colorimetric assays and bone histomorphometric analyses were performed on cancellous bone of femoral epiphysis and metaphysis using a photomicroscope and a digital camera. Histomorphometric parameters demonstrated a significant bone loss due to methylprednisolone administration, which was partly restored by eicosapentaenoic acid. A strong inverse correlation was observed between the serum total cholesterol concentration and epiphyseal trabecular width and metaphyseal trabecular osteoid width [R = -0.82, P = 0.04 and R = -0.86, P = 0.01, respectively]. Serum triglycerides concentration was also strongly and inversely correlated with the above mentioned parameters [R = -0.88, P = 0.02 for epiphyseal trabecular width and R = -0.81, P = 0.02 for metaphyseal trabecular osteoid width]. The correlation between the lipid-lowering and bone-protective effects of eicosapentaenoic acid may be helpful in the clarification of its effects on bone and lipid metabolism

[Bioequivalence study of two closantel formulations in sheep]

Bioequivalence study is a scientific and practical method used to compare the quality of a generic drug with a reference product. This study aimed to examine the bioequivalence of two closantel formulations produced with different sources of raw material by a domestic pharmaceutical company. Due to long half-life of closantel, the study carried out by a parallel method. Thirty sheep were divided into 2 groups of 15 each. In the first group [test group] each sheep received 500 mg bolus of closantel and in the second group [reference group], each sheep received a 500 mg bolus of closantel produced with a raw material from a Belgium Company. Blood samples were collected at 0, 4, 8, 12, 16, 20, 24, 32, 48 and 72 hours after drug administration. An HPLC system was used to determine the amount of closantel in plasma. Pharmacokinetic parameters including area under curve [AUC], C[max], T[max], Kel and t[1/2] of closantel were determined in each sheep. A t-student test was used to analyze and compare the results. The mean +/- SD of C[max] in reference and test groups were 56.38 +/- 14.28 micro g/ml, 51.44 +/- 10.55, respectively. T[max] in reference and test groups were 22.93 +/- 2.81, 23.72 +/- 1.83 h, respectively. AUC [0-72] in reference and test drugs were 2049.1 +/- 421.2 and, 1795.1 +/- 421.2, respectively. AUC [0- infinity] in reference and test were 2557.3 +/- 621.5 and 2171.1 +/- 80.K[el] in reference group was 0.0321 +/- 0.0144 while in test it was 0.0348 +/- 0.0128. t[1/2] in reference and test groups were 24.85 +/- 8.34 h and, 22.29 +/- 8.03 h, respectively. In conclusion, the results of this study showed that there was not significant difference between reference and test group, suggesting that two products were bioequivalent

Biochemical, hematological and pathological alterations associated with ascites in broilers and the role of oxygen-derived free radicals

Three hundred and fifteen day -old chickens were used to test the relationship between oxygen- derived free radicals and the biochemical, hematological and pathological alterations[associtd with ascites]. They were randomly divided into three experimental groups and ascites were developed in two groups of animals by exposing them to low temperature or administration of triiodothyronine [T[3],], and the third group was used as control. Different hematological, biochemical and pathological tests were used to determine the incidence of ascites in birds. These include total red blood cell [RBC], hematochrit [PCV], activities of alanine transaminase [ALT] and aspartate transaminase [AST] and the ratio of right ventricular weight to total ventricular weight [RV/TV]. Two hydroxylated salicylic acid [SA] metabolites, 2, 3- and 2, 5-dihydroxy benzoic acids [2, 3- and 2, 5-DHBA], were measured. by HPLC system to detect the generation of hydroxyl [OH] radicals. An analysis of variance [ANOVA] was used to determine the differences between different experimental groups. Ascites syndrome was observed in T[3] and low temperature treated groups as shown by necropsy changes and significant increases [p < 0.05] in the amount of RBC, PCV, ALT, AST and the ratio of RV/TV. While the significant increase was shown in the amounts of 2,3- and 2,5-DHBAfrom day 11, the alteration in the values of enzymes and hematoloic parameters and ratio of RV/TV occurred from days 18, 25 and 32 respectively. It can be concluded that OH radicals may be involved in the initiation of ascites syndrome, but the biochemical, hematological and pathological changes induced by these agents, can cause ascites and other alterations

[Simultaneous determination of salicylic acid and its hydroxylated metabolites in poultry serum by HPLC]

To introduce an HPLC method for indirect measuring of hydroxyl radicals in poultry serum. Chromatographic study. Poultry serum. By acidification of serum with 1.0 M HCl, salicylic acid [SA] and its hydroxylated metabolites were extracted into diethylether, dried and redissolved in mobile phase buffer and HCl. It was filtered and 20 micro L of the filtrate injected into the HPLC system. The chromatographic condition was as follows: acetate-citrate buffer [94%]: methanol [6%] as mobile phase run at 1.2 ml/min through a C18 column using UV and EC detectors concurrently. Descriptive statistics good. Separations among these compounds obtained without any interference with poultry serum elements. Calibration curves for SA and Dihydroxy benzoic acids [DHBAs] were linear at 0.28-88 micro g/ml [R[2] =0.996] and 0.3 -12.3 micro g/ml [R[2] = 0.998], respectively. Detection limit for SA and DHBAs were 0.56 micro g/ml and 0.3 micro g/ml, respectively. Precision of the method [CV%] as intra- and inter-day variations were defined for SA [2.5 -6.5%, 4.4-6.8%], 2,3-DHBA [4.2-8.5%, 5.8-9.0%] and 2, 5-DHBA [4.1-6.8%, 5.9- 7.4%]. Recovery of the method for SA and DHBA were 87 +/- 5% and 92 +/- 4%, respectively. This method is useful for simultaneous determination of SA and its hydroxylated metabolites in poultry serum as an indirect measurement of hydroxyl radicals

Effects of enrichment with ascorbil palmitate and starvation in cold condition on ascorbic acid content in nauplii of Artemia urmiana

A trial was conducted to study the effects of different periods of enrichment with ascorbil pulmitate and starvation in cold condition on ascorbic acid [AA] content in nauplii of Artemia urmiana. Four treatment groups with 4 replicates of freshly hatched nauplii were kept at 28°C in incubators containing enrichment medium for 0, 12, 18 and 24 hrs, respectively. Then all of them starved at 5°C for 0, 12, 18 and 24 hrs. AA content was determined using a reversed-phase high performance liquid chromatography coupled with an electrochemical detector. The results showed that nauplii of A urmiana had high levels of AA in their bodies [1534 +/- 166 ug/g DW]. AA content increased following enrichment and reached to their maximum after 18 hrs [3600 +/- 282] and then reduced by 24 hrs of enrichment [2938 +/- 254]. There was a significant difference in AA levels between non-enriched and enriched groups [P<0.05]. Although AA content enhanced in all groups during starvation periods at 5°C, the increases were not significant. However, significant correlations could be observed between duration of starvation and increasing of AA levels in non-enriched, 12 h and 18 h enriched groups. In conclusion, nauplii of A. urmiana had high levels of AA and enrichment with ascorbil plamitate increased their AA content significantly