Boswellic acids: a review on its pharmacological properties, molecular mechanism and bioavailability

Boswellic acids is a general term for a series of pentacyclic triterpenoid compounds that are isolated from the oleogin resin of the Boswellia genus and serve as the main active ingredient.It exhibits a wide range of biological activities,such as anti-inflammatory,anti-cancer,antibacterial,antiviral,hepatoprotective,neuroprotective,anti-diabetic,and anti-thrombotic properties.As a result,it has gained significant recognition among practitioners of traditional Chinese and Indian medicine.These biological effects may be associated with multiple molecular targets and signal transduction pathways.However,the poor pharmacokinetic properties of the substance lead to lower bioavailability,which affects its effectiveness.To address this issue,scientists have proposed a number of strategies,such as solid dispersions,phytosome®technologies,and novel drug delivery systems.This article aims to provide a comprehensive overview for boswellic acids on the phytochemistry,molecular mechanisms,potential therapeutic applications,and strategies to improve bioavailability.

Enhancement in Bioavailability of CurCousin®, A Minor Metabolite from Curcuma longa by Addition of BioPerine® —A Pharmacokinetic Study

In recent years, metabolic syndrome has been a growing health concern across the world. The role of nutraceuticals and functional foods in this area has a significant place due to the adverse effects of contemporary modes of treatment. CurCousin® is a nutritional ingredient containing bioactive Calebin A, (analog of Curcumin) with self-affirmed GRAS status. CurCousin® has been a clinically studied dietary supplement ingredient with a positive impact on body weight, lipid levels and metabolic health. Bioenhancers play an important role in increasing the bioavailability of the active in turn enhancing efficacy as well as reducing the dosage required to achieve the therapeutic effect. This study investigated the possible pharmacokinetic interaction between CurCousin® at two different doses (2.25 and 4.5 mg/kg) in the presence and absence of BioPerine® (0.27 mg/kg), a natural bioenhancer in Sprague-Dawley rats. The results revealed that the addition of BioPerine® into CurCousin® (2.25 mg/kg) half the dose when administered enhances the bioavailability and was equipotent to CurCousin® (4.5 mg/kg) double the dose without BioPerine®. Thus, leading to future clinical studies to evaluate its improved pharmacological efficacy as well as reduced therapeutic dosage.

Fabrication of taxifolin loaded zein-caseinate nanoparticles and its bioavailability in rats

Taxifolin loaded zein-caseinate nanoparticles(TZP)were fabricated by the anti-solvent method and were used as an oral delivery vehicle to improve their bioavailability in the rat.The formulations of TZP were optimized.With mass ratio of 1:1:2 between taxifolin,zein and sodium caseinate,the particle size andζpotential of TZP were(168.74±0.35)nm and−(57.67±0.25)mV,while the encapsulation and loading efficiency of taxifolin were(85.83±0.89)%and(17.11±0.88)%,respectively.After freeze-drying,TZP exhibited excellent redispersibility in water without aggregation.Physicochemical characterization showed that taxifolin existed in amorphous form in TZP and its interaction with the protein was observed.After encapsulating in TZP,the excellent dispersion of taxifolin in water signifi cantly improve its diffusion velocity through a semipermeable membrane.After oral administration,taxifolin and its 5 metabolites were identifi ed in rat plasma by ultra high performance liquid chromatography(UPLC)with quadrupole time-of-flight mass spectrometry(UPLC-QTOF-MS).The dynamic variation of taxifolin and its metabolites in plasma were then quantifi ed by UPLC with a triple-quadrupole typemass spectroscopy(UPLC-QqQ-MS/MS).A pharmacokinetic study showed that the bioavailability of taxifolin increased from 0.35%to 0.52%through TZP fabrication.The plasma concentration of taxifolin glucuronide and methylated taxifolin glucuronide was much higher than taxifolin.Glucuronidation was the dominating metabolism pathway of taxifolin in vivo.

Effect of Glycosylation on the Physicochemical Properties,Structure and Iron Bioavailability of Ferritin Extracted from Tegillarca granosa

Iron deficiency anemia(IDA)is a major global health problem.Tegillarca granosa has been considered as an excellent source of iron given its high content of iron-binding protein,ferritin.The aim of the present study was to determine the physicochemical properties,protein structures,and iron uptake of ferritin extracted from T.granosa,and to evaluate the potential impacts of chitosan glycosylation on these characteristics.Based on Box-Behnken design and response surface methodology,the optimal conditions for glycosylation included a ferritin/chitosan mass ratio of 4:1,a pH of 5.5,a reaction time of 10 min,and a reaction temperature of 50℃.Glycosylation caused decreased surface hydrophobicity and elevated water-holding capacity of ferritin due to the introduction of hydrophilic groups.Additionally,glycosylation improved antioxidant capacity of ferritin by 20.69%–189.66%,likely owing to the protons donated by saccharide moiety to terminate free radical chain reaction.The in vitro digestibility of ferritin was elevated by 22.56%–104.85%after glycosylation,which could be associated with lessβ-sheet content in secondary structure that made the glycosylated protein less resistant to enzymatic digestion.The results of the iron bioavailability in Caco-2 cells revealed that ferritin(78.85–231.77 ngmg^(−1))exhibited better iron bioavailability than FeSO4(51.48–114.37 ngmg^(−1))and the values were further elevated by glycosylation with chitosan(296.23–358.20 ngmg^(−1)),which may be related to the physicochemical properties of ferritin via glycosylation modification.These results provide a basis for the development of T.granosa derived ferritin and its glycosylated products,and can promote the utilization of aquatic resources.

The chemical characteristics of different sodium iron ethylenediaminetetraacetate sources and their relative bioavailabilities for broilers fed with a conventional corn‑soybean meal diet

Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed higher Fe bioavailabilities for broilers.Sodium iron ethylenediaminetetraacetate(NaFeEDTA)is a trivalent organic Fe source with the strongest chelating ligand EDTA.However,the bioavailability of Fe when administered as NaFeEDTA in broilers and other agricultural animals remains untested.Herein,the chemical characteristics of 12 NaFeEDTA products were determined.Of these,one feed grade NaFeEDTA(Qf=2.07×10^(8)),one food grade NaFeEDTA(Qf=3.31×10^(8)),and one Fe proteinate with an extremely strong chelation strength(Fe-Prot ES,Qf value=8,590)were selected.Their bioavailabilities relative to Fe sulfate(FeSO_(4)·7H_(2)O)for broilers fed with a conventional corn-soybean meal diet were evaluated during d 1 to 21 by investigating the effects of the above Fe sources and added Fe levels on the growth performance,hematological indices,Fe contents,activities and gene expressions of Fe-containing enzymes in various tissues of broilers.Results NaFeEDTA sources varied greatly in their chemical characteristics.Plasma Fe concentration(PI),transferrin saturation(TS),liver Fe content,succinate dehydrogenase(SDH)activities in liver,heart,and kidney,catalase(CAT)activity in liver,and SDH mRNA expressions in liver and kidney increased linearly(P<0.05)with increasing levels of Fe supplementation.However,differences among Fe sources were detected(P<0.05)only for PI,liver Fe content,CAT activity in liver,SDH activities in heart and kidney,and SDH mRNA expressions in liver and kidney.Based on slope ratios from multiple linear regressions of the above indices on daily dietary analyzed Fe intake,the average bioavailabilities of Fe-Prot ES,feed grade NaFeEDTA,and food grade NaFeEDTA relative to the inorganic FeSO_(4)·7H_(2)O(100%)for broilers were 139%,155%,and 166%,respectively.Conclusions The bioavailabilities of organic Fe sources relative to FeSO_(4)·7H_(2)O were closely related to their Qf values,and NaFeEDTA sources with higher Qf values showed higher Fe bioavailabilities for broilers fed with a conventional corn-soybean meal diet.

A nano-cocrystal strategy to improve the dissolution rate and oral bioavailability of baicalein

Baicalein(BE) is one of the main active flavonoids representing the variety of pharmacological effects including anticancer, anti-inflammatory and cardiovascular protective activities, but it's very low solubility, dissolution rate and poor oral absorption limit the therapeutic applications. In this work, a nano-cocrystal strategy was successfully applied to improve the dissolution rate and bioavailability of BE. Baicalein-nicotinamide(BE-NCT) nanococrystals were prepared by high pressure homogenization and evaluated both in vitro and in vivo. Physical characterization results including scanning electron microscopy, dynamic light scattering, powder X-ray diffraction and differential scanning calorimetry demonstrated that BE-NCT nano-cocrystals were changed into amorphous state with mean particle size of 251.53 nm. In the dissolution test, the BE-NCT nano-cocrystals performed 2.17-fold and 2.54-fold enhancement than BE coarse powder in FaSSIF-V2 and FaSSGF. Upon oral administration, the integrated AUC0-t of BE-NCT nano-cocrystals(6.02-fold) was significantly higher than BE coarse powder(1-fold), BE-NCT cocrystals(2.87-fold) and BE nanocrystals(3.32-fold). Compared with BE coarse powder, BE-NCT cocrystals and BE nanocrystals, BENCT nano-cocrystals possessed excellent performance both in vitro and in vivo evaluations.Thus, it can be seen that nano-cocrystal is an appropriate novel strategy for improving dissolution rate and bioavailability of poor soluble natural products such as BE.

Fractions and Bioavailability of Soil Inorganic Phosphorus in the Loess Plateau of China under Different Vegetations

Plants play an important role in soil phosphorus nutrition. However, the effect of plants on phosphorus nutrition in soils of the Loess Plateau of China is not well understood. This study was conducted to reveal the relationships between plants and phosphorus＇ fractions and availability in the Loess Plateau of China. Twenty-two plant communities were surveyed and soil samples under different plant canopies were collected for the determination of soil properties and inorganic phosphorus fractionation. The results showed that Leguminosae and Lilaceae reduced pH and increased organic matter, cation exchange capacity, total and Olsen phosphorus in soils under their canopies, while Labiatae and Rosaceae increased pH and decreased organic matter, cation exchange capacity, total and Olsen phosphorus in soils under their canopies. The contents of Ca2P, CasP, AI-P and Fe-P were highly related with soil Oisen phosphorus. They were all higher in soils under Leguminosae and Lilaceae and lower in softs under Labiatae and Rosaceae. The results of this study indicate that Leguminosae and Lilaceae improved phosphorus nutrition in soils, yet Labiatae and Rosaceae impeded the improvement of phosphorus nutrition in soils under their canopies, which will be of more help to instruct vegetation restoration in the region and provide information for soil development.

Bioavailability of bound residue derived from ^(14)C-labeled chlorsulfuron in soil and its mechanism of phytotoxicity

The bioavailability of bound residue(BR) derived from 14 C-labeled chlorsulfuron in soil and effect of the main components of the BR on growth of rape(brassica napus) and rice(Oryza sativa L.) were investigated. The results showed that the BR with the concentration of 0 28 and 0 56 nmol/g air-dried soil, which was calculated by special radioactivity of 14 C-labeled chlorsulfuron parent compound, resulted in significant depression effect on growth of rape seedling. It was assured that the main components(2-amino-4-methoxyl-6-methyl-1,3,5-triazine, 2-amino-4-hydroxyl-6-methyl-1,3,5-triazine, and 2-chloro-benzenesul-f onamide) of the BR did not inhibit the growth of rape and rice. LC-MS analysis demonstrated that the parent compound previously bound to the soil matrix could be again released and transformed into methanol-extractable residue during the course of rape growth. It was concluded that the molecular leading to the phytotoxicity to rape and rice in the BR is still the parent compound.

Study on Relative Bioavailability of Famotidine Sustained-release Tablets in Healthy Volunteers

对法莫替丁缓释片在１６名健康志愿者体内的生物利用度进行了研究。以高效液相色谱法测定血药浓度，依据美国药典２３版中关于生物等效性指南的有关要求处理数据。结果表明：单剂量给药，本品的达峰时间为８１３±０３４ｈ，峰浓度为６９５２±３００ｎｇ／ｍｌ，相对生物利用度为１１２４±８６％；多剂量给药达稳态后，本品的峰浓度为８６１４±２９５ｎｇ／ｍｌ，血药浓度波动度为１４０６±１３５％。对ＡＵＣ进行双单侧检验的结果证明本品与市售普通片生物等效。

Phyto-phospholipid complexes(phytosomes): A novel strategy to improve the bioavailability of active constituents

Although active constituents extracted from plants show robust in vitro pharmacological effects, low in vivo absorption greatly limits the widespread application of these compounds. A strategy of using phyto-phospholipid complexes represents a promising approach to increase the oral bioavailability of active constituents, which is consist of ‘‘label-friendly'phospholipids and active constituents. Hydrogen bond interactions between active constituents and phospholipids enable phospholipid complexes as an integral part. This review provides an update on four important issues related to phyto-phospholipid complexes: active constituents, phospholipids, solvents, and stoichiometric ratios. We also discuss recent progress in research on the preparation, characterization, structural verification, and increased bioavailability of phyto-phospholipid complexes.

Andrographolide Loaded in Micro-and Nano-Formulations: Improved Bioavailability, Target-Tissue Distribution, and Efficacy of the “King of Bitters”

Andrographolide (AG) is the characteristic constituent of Andrographis paniculata, of the Acanthaceae family. This plant is a well-known Asian medicinal plant that is widely used in India, China, and Thailand. A monograph of Herba Andrographidis (Chuanxinlian) is included in the Chinese Pharmacopoeia, which reports that this decoction can “remove heat, counteract toxicity, and reduce swellings.” The numerous potential activities of AG range from anti-inflammatory to anti-diabetic action, from neuroprotection to antitumor activity, and from hepatoprotective to anti-obesity properties. However, AG has low bioavailability and poor water solubility, which can limit its distribution and accumulation in the body after administration. In addition, AG is not stable in gastrointestinal alkaline and acidic environments, and has been reported to have a very short half-life. Among the diverse strategies that have been adopted to increase AG water solubility and permeability, the technological approach is the most useful way to develop appropriate delivery systems. This review reports on published studies related to microparticles (MPs) and nanoparticles (NPs) loaded with AG. MPs based on polylactic-glycolic acid (PLGA), alginic acid, and glucan derivatives have been developed for parenteral oral and pulmonary administration, respectively. NPs include vesicles (both liposomes and niosomes);polymeric NPs (based on polyvinyl alcohol, polymerized phenylboronic acid, PLGA, human serum albumin, poly ethylcyanoacrylate, and polymeric micelles);solid lipid NPs;microemulsions and nanoemulsions;gold NPs;nanocrystals;and nanosuspensions. Improved bioavailability, target-tissue distribution, and efficacy of AG loaded in the described drug delivery systems have been reported.

Application of hot melt extrusion to enhance the dissolution and oral bioavailability of oleanolic acid

The aim of this study was to improve the in vitro dissolution rate and oral bioavailability of oleanolic acid(OA), a water insoluble drug belonging to BCS class IV. Hot melt extrusion(HME) was applied to develop OA amorphous solid dispersions. The characterizations of the optimal formulation were performed by differential scanning calorimetry, X-ray powder diffraction, Fourier transform infrared spectroscopy and in vitro dissolution test.The in vivo pharmacokinetic study was conducted in rats. As a result, OA solid dispersion based on PVP VA 64(OA-PVP) was successfully prepared. In the dissolution medium containing 0.3% SDS, OA-PVP dramatically increased the releasing rate of OA compared with the physical mixture(PM-PVP) and commercial tablet. Furthermore, OA-PVP exhibited higher AUC(P < 0.05) and Cmax(P < 0.05) than PM-PVP and commercial tablet. The superior dissolution property and bioavailability of OA-PVP mainly attributed to the amorphous state of OA in PVP VA64 and the well dispersion caused by thermal melting and shearing. Overall, hot melt extrusion was an efficient strategy to enhance the dissolution rate and oral bioavailability of OA.

Reduction of arsenic bioavailability by amending seven inorganic materials in arsenic contaminated soil

Seven inorganic amendment materials were added into arsenic （As） contaminated soil at a rate of 0.5% （w/w）; the materials used were sepiolite, red mud, iron grit, phosphogypsum, ferrihydrite, iron phosphate, and layered double oxides （LDO）. Plant growth trials using rape （edible rape, Brassia campestris L.） as a bio-indicator are commonly used to assess As bio- availability in soils. In this study, B. campestris was grown in a contaminated soil for 50 days. All of the inorganic amend- ments significantly inhibited the uptake of As by B. campestris. Following soil treatment with the seven aforementioned inorganic ammendments, the As concentrations in the edible parts of B. campestris were reduced by 28.6, 10.5, 8.7, 31.0, 47.4, 25.3, and 28.8%, respectively, as compared with the plants grown in control soil. The most effective amendment was ferdhydrite, which reduced As concentration in B. campestris from 1.84 to 0.97 mg kg-~, compared to control. Furthermore, ferrihydrite-treated soils had a remarkable decrease in both non-specifically sorbed As and available-As by 67 and 20%, respectively, comparing to control. Phosphogypsum was the most cost-effective amendment and it showed excellent performance in reducing the water soluble As in soils by 31% and inhibiting As uptake in B. campestris by 21% comparing to control. Additionally, obvious differences in As transfer rates were observed in the various amendments. The seven amendment materials used in this study all showed potential reduction of As bioavailability and influence on plant growth and other biological processes still need to be further explored in the long term.

Bioavailability and Immunity Response in Broiler Breeders on Organically Complexed Zinc Supplementation

Two hundred and sixty four broiler breeder hens of 32 weeks of age were distributed randomly in four dietary treatments. The dietary treatments were T0: Broiler breeder ration containing 40 ppm zinc (basal 29.8 ppm + 10.2 ppm inorganic zinc), T1: T0 + organic zinc (zinc methionine) @ 20 ppm, T2: T0 + organic zinc @ 40 ppm and T3: T0 + organic zinc @ 60 ppm. The experiment was continued from 32 to 48 weeks of age. At 48 weeks, the weight of lymphoid organs, zinc levels in organs and immunity response were determined. The faecal zinc level was determined at monthly interval. The weight lymphoid organs of different treatment groups (both organic and inorganic zinc fed groups) of the broiler breeders did not differ significantly (P > 0.05). The cellular immune response of breeder birds to PHA-P was significantly (P 0.05) higher in group T3 than the rest of treated groups. The antibody titre to SRBC differed among the treated groups. The zinc content of serum of broiler breeders of all the groups did not differ significantly (P > 0.05) in all the periods of study. Zinc content in liver and tibia of broiler breeders in different dietary treatments of zinc differed significantly (P 0.05) with higher levels were obtained on increasing zinc concentration in the diet. The zinc level in the spleen and kidney of the broiler breeders in different dietary treatments did not differ significantly (P > 0.05). The average zinc content in the faeces of broiler breeder during 35 to 43 week of age did not differ significantly (P > 0.05) among the treated groups. At 48 weeks of age, zinc content of the faeces of T3 was found to be significantly (P 0.05) higher than the rest of treated groups. Similarly, during the overall experimental period analysis, it was found that zinc levels in the faeces of T2 and T3 were significantly (P 0.05) higher than T1 and T0.

Aging effect on the mobility and bioavailability of copper in soil

Aging effect on the mobility and bioavallability of copper （Cu） was investigated using a spiked soil with different incubation periods from 3 to 56 d. Wheat was planted and earthworms were cultured separately in the incubated soils. The mobility of Cu in soil was evaluated by a chemical fractionation scheme and the toxicity and bioavailability were assessed by measuring the biomass and Cu concentration in tissues. Results showed that aging had a significant effect on Cu fraction distribution, of which Cu tended to incorporate from the exchangeable into more stable fractions such as the reducible and oxidisable fractions. However, aging had little effect on Cu bioavailability to wheat and earthworm. Comparing the soil being incubated for 3 d and 56 d, Cu concentration in wheat roots decreased from 14.5 to 12.8 mg/kg, and no significant changes in Cu concentration were observed in both wheat shoots and earthworms. The Cu concentration was around 2.0 and 50 mg/kg for wheat shoots and earthworms, respectively, irrespective of soil incubation time. The CaC12-extractable Cu had a linear relationship with Cu concentration in wheat roots （R2 = 0.65, P 〈 0.05）, but no linear relationship can be found for wheat shoots and earthworms. Biological control may be more crucial for Cu accumulation in organism than the changes in soil Cu fraction caused by aging.

Effects of Carbonate on Exchangeability and Bioavailability of Exogenous Neodymium in Soil

The effects of carbonate on the exchangeability and the bioavailability of exogenous neodymium in soil were studied by Nd-147 isotopic tracer method. Exchangeable Nd was extracted by I mol(.)L(-1) NaAc (pH8.2) in the experiment. The results indicate that whether carbonate exists in soil or not, beyond 99% of exogenous Nd is adsorbed by soil. Low-concentration carbonate (0.8 similar to 1.6 g(.)kg(-1)) can reduce exchangeable Nd concentration in soil, while high-concentration carbonate (4.0 g(.)kg(-1)) impacts little on the exchangeable Nd concentration. In addition, carbonate of 0.8 similar to 1.6 g(.)kg(-1) in soil can inhibit wheat seedlings to absorb Nd. However, when the carbonate concentration rises to 4.0 g(.)kg(-1) the inhibition will become indistinct.

Bioavailability enhancers of herbal origin:An overview

Recently,the use of herbal medicines has been increased all over the world due to their therapeutic effects and fewer adverse effects as compared to the modern medicines.However,many herbal drugs and herbal extracts despite of their impressive in-vitro findings demonstrates less or negligible in-vivo activity due to their poor lipid solubility or improper molecular size,resulting in poor absorption and hence poor bioavailability.Nowadays with the advancement in the technology,novel drug delivery systems open the door towards the development of enhancing bioavailability of herbal drug delivery systems.For last one decade many novel carriers such as liposomes,microspheres,nanoparticles,transferosomes,ethosomes,lipid based systems etc.have been reported for successful modified delivery of various herbal drugs.Many herbal compounds including quercetin,genistein,naringin,sinomenine,pipeline,glycvrrhizin and nitrile glycoside have demonstrated capability to enhance the bioavailability.The objective of this review is to summarize various available novel drug delivery technologies which have been developed for delivery of drugs(herbal),and to achieve better therapeutic response.An attempt has also been made to compile a profile on bioavailability enhancers of herbal origin with the mechanism of action(wherever reported)and studies on improvement in drug bioavailability,exhibited particularly by natural compounds.

Assessment of Iron Bioavailability in Ten Kinds of Chinese Wheat Flours Using an in vitro Digestion/Caco-2 cell Model

Abstract Objective To compare iron bioavailability （Fe BV） from ten selected kinds of Chinese wheat flours in order to provide scientific basis for further human trials and enable plant breeding programs to screen biofortified wheat cultivars. Methods An in vitro digestion/Caco-2 cell model was used to assess Fe BV of ten flour samples from six leading Chinese wheat cultivars and the stability of Fe BV in one cultivar was studied across three growing environments. Results Significant differences were observed in both Fe BV and Fe bioavailability per gram of food （Fe BVPG） among cultivars （P〈0.01） grown at the same location with the same flour extraction rate. Zhongyou 9507 and Jingdong 8 had Fe BV 37%-54% and Fe BVP（3 103%-154% higher than the reference control. In the Anyang environment, Zhongyou 9507 had a higher wheat flour-Fe level and Fe BVPG. Differences in Fe BV were detected in cultivars with different flour extraction rates. Conclusion Zhongyou 9507 and Jingdong 8 were identified as the most promising cultivars for further evaluation of efficacy by using human subjects. The growing environments had no effect on Fe BV, but did have a significant effect on Fe BVPG. Fe bioavailabilities in low-extraction （40%） flours were higher than those in high-extraction （78%） flours.

Nanocrystals for enhancement of oral bioavailability of poorly water-soluble drugs

Nanocrystals,a carrier-free colloidal delivery system in nano-sized range,is an interesting approach for poorly soluble drugs.Nanocrystals provide special features including enhancement of saturation solubility,dissolution velocity and adhesiveness to surface/cell membranes.Several strategies are applied for nanocrystals production including precipitation,milling,high pressure homogenization and combination methods such as Nano-Edge^(TM),SmartCrystal and Precipitation-lyophilization-homogenization(PLH)technology.For oral administration,many publications reported useful advantages of nanocrystals to improve in vivo performances i.e.pharmacokinetics,pharmacodynamics,safety and targeted delivery which were discussed in this review.Additionally,transformation of nanocrystals to final formulations and future trends of nanocrystals were also described.

Study on the Pharmacokinetics and Relative Bioavailability of Irbesartan Capsules in Healthy Volunteers

The pharmacokinetics and relative bioavailability were studied in 18 healthy volunteers. A single oral dose of 150 mg irbesartan capsule (test) or tablet (reference) was given to each volunteer according to a randomized 2 way crossover study. The concentrations in plasma were determined by HPLC UV method. The main parameters of irbesartan capsules were: C max : 1.502±0.295 μg/ml, t max : 1.44±0.34 h, t 1/2 : 20.21±14.71 h, AUC 0 t : 11.087±3.443 μg/ml -1 ·h. The relative bioavailability of capsule to tablet was (101.4±28.9) %. The results of statistical analysis showed that two formulations were bioequivalent.