the compound of formula i is a dibenzothiazepine that has shown antidopaminergic activity . it has been shown to interact with a broad range of neurotransmitter receptors but has a higher affinity for serotonin ( 5 - ht 2 ) receptors relative to dopamine ( d 2 ) receptors in the brain . preliminary positron emission topography ( pet ) scans of primate subjects showed that the compound of formula i reaches the brain and occupies d 1 , d 2 , 5 - ht 2a , and 5 - ht 1a receptors and the 5ht transporter . however , the compound of formula i was not shown to be efficacious in a mouse standard apomorphine swim test ( p . o .) and in a rat d - ampehtamine locomotor activity test ( s . c .). the compound of formula i has also been shown to have partial 5ht 1a agonist activity and has shown in - vivo efficacy in mouse and rat models for depression . the compound of formula i may be used as an antipsychotic with a reduction in the potential to cause side effects such as acute dystonia , acute dyskinesia , as well as tardive dyskinesia typically seen with antipsychotics . results generated from alpha receptor binding data further suggest that the compound of formula i will have improved tolerability over that of quetiapine and suggest that one would observe a reduced incidence of hypotension . further the compound of formula i may be used to treat patients of all ages and is advantageous in the treatment of elderly patients . the compound of formula i may be made by a variety of methods known in the chemical arts . the compound of formula i may be prepared by starting from known compounds or readily prepared intermediates including taking the lactam of formula ii : which may be prepared by methods well known in the literature , for example , as described by j . schmutz et al . helv . chim . acta ., 48 : 336 ( 1965 ). the lactam of formula ii is treated with phosphorus chloride to generate the imino chloride of formula iii : the imino chloride of formula iii may also be generated with other agents such as thionyl chloride or phosphorous pentachloride . the imino chloride is then reacted with piperazine to give the compound of formula i . the compound of formula i provided herein is useful as a free base , but may also be provided in the form of a pharmaceutically acceptable salt , and / or in the form of a pharmaceutically acceptable solvate ( including hydrates ). for example , pharmaceutically acceptable salts of formula i include those derived from mineral acids such as for example : hydrochloric acid , nitric acid , phosphoric acid , sulfuric acid , hydroiodic acid , nitrous acid , and phosphorous acid . pharmaceutically acceptable salts may also be developed with organic acids including aliphatic mono dicarboxylates and aromatic acids . other pharmaceutically acceptable salts of formula i include but are not limited to hydrochloride , sulfate , pyrosulfate , bisulfate , bisulfite , nitrate , and phosphate . a clinician may determine the effective amount by using numerous methods already known in the art . the term “ treating ” within the context of the present invention encompasses to administer an effective amount of the compound of the present invention , to mitigate either a pre - existing disease state , acute or chronic , or a recurring symptom or condition . this definition also encompasses prophylactic therapies for prevention of recurring conditions and continued therapy for chronic disorders . a particular amount of the compound of formula i or its pharmaceutically acceptable salt can be administered in an amount up to about 750 mg per day ; particularly from about 75 mg to about 750 mg per day . in another particular aspect of the invention the amount of the compound of formula i , or its pharmaceutically acceptable salt , may be administered from about 1 mg to about 600 mg per day . in another aspect of the invention the compound of formula i or its pharmaceutically acceptable salt may be administered from about 100 mg to about 400 mg per day . the compound of formula i or its pharmaceutically acceptable salt may be administered comprising a predetermined dosage of the compound of formula i to a mammal between one and four times a day , wherein the predetermined dosage is from about 1 mg to about 600 mg . the present invention also provides a method of treating the symptoms or conditions provided herein comprising the step of administering an initial predetermined dosage of a compound of formula i to a human patient twice a day , wherein the predetermined dosage is between 1 mg and 30 mg with increases in increments of 1 - 50 mg twice daily on the second and third day as tolerated . thereafter , further dosage adjustments can be made at intervals of no less than 2 days . in one embodiment of the invention the pharmaceutical composition comprises up to about 750 mg of the compound of formula i or its pharmaceutically acceptable salt , particularly from about 75 mg to about 750 mg . in another embodiment of the invention , the pharmaceutical composition may comprise from about 1 mg to about 600 mg of the compound of formula i or a pharmaceutically acceptable salt thereof in another embodiment of the invention , the pharmaceutical composition may comprise from about 100 mg to about 400 mg of the compound of formula i or a pharmaceutically acceptable salt thereof . the pharmaceutical composition of the invention may accordingly be obtained by conventional procedures using conventional pharmaceutical excipients . thus , pharmaceutical compositions intended for oral use may contain , for example , one or more coloring , sweetening , flavoring and / or preservative agents . for preparing pharmaceutical compositions from the compound of formula i of this invention , inert , pharmaceutically acceptable carriers can be either solid or liquid . solid form preparations include powders , tablets , dispersible granules , capsules , cachets , and suppositories . the composition of the invention may be administered by any route including orally , intramuscularly , subcutaneously , topically , intranasally , intraperitoneally , intrathoracially , intravenously , epidurally , intrathecally , intracerebroventricularly and by injection into the joints . the amount of active ingredient that is combined with one or more excipients to produce a single dosage form , such as an oral dosage form , will necessarily vary depending upon the host treated and the particular route of administration . the size of the dose for therapeutic or prophylactic purposes of a compound of the formula i will naturally vary according to the nature and severity of the symptoms or conditions , the age and sex of the animal or patient and the route of administration , according to well known principles of medicine . another aspect of the invention provides a compound of formula i , or its pharmaceutically acceptable salt or solvate thereof , for use in treating the symptoms or conditions provided herein . in a further aspect , the present invention provides the use of a compound of formula 1 , or a pharmaceutically acceptable salt or solvate thereof , in the manufacture of a medicament for use in treating the symptoms or conditions provided herein . in a further aspect , the present invention relates to methods of treating at least one of the above described symptoms or conditions comprising administering to a mammal an effective amount of the compound of formula i or its pharmaceutically acceptable salt and one or more of other therapeutically active agents , benzodiazepines , 5 - ht 1a ligands , 5 - ht 1b ligands , 5 - ht 1d ligands , mglur2a agonists , mglur5 antagonists , antipsychotics , nk1 receptor antagonists , antidepressants , serotonin reuptake inhibitors , gaba ii ligands , or mood stabilizers administered in combination as part of the same pharmaceutical composition , as well as to methods in which such active agents are administered separately as part of an appropriate dose regimen designed to obtain the benefits of combination therapy . the appropriate dose regimen , the amount of each dose of an active agent administered , and the specific intervals between doses of each active agent will depend upon the subject being treated , the specific active agent being administered and the nature and severity of the specific disorder or condition being treated . in general , the compounds of this invention , when used as either a single active agent or when used in combination with another active agent , will be administered to a subject in an amount up to about 750 mg per day , in single or divided doses . such compounds may be administered on a regimen of up to 6 times per day , preferably 1 to 4 times per day . variations may nevertheless occur depending upon the subject being treated and the individual response to the treatment , as well as on the type of pharmaceutical formulation chosen and the time period and interval at which such administration is carried out . in some instances , dosage levels below the lower limit of the aforesaid range may be more than adequate , while in other cases larger doses may be employed to achieve the desired effect , provided that such larger doses are first divided into several small doses for administration throughout the day . exemplary benzodiazepines may include but are not limited to adinazolam , alprazolam , bromazepam , clonazepam , chlorazepate , chlordiazepoxide , diazepam , estazolam , flurazepam , balezepam , lorazepam , midazolam , nitrazepam , oxazepam , quazepam , temazepam , triazolam and equivalents thereof . exemplary 5 - ht 1a and / or 5ht 1b ligands may include but are not limited to buspirone , alnespirone , elzasonan , ipsapirone , gepirone , zopiclone and equivalents thereof . exemplary mglur 2 agonists may include ( 1s , 3r )- 1 - aminocyclopentane - 1 , 3 - dicarboxylic acid , ( 2s , 3s , 4s ) alpha -( carboxycyclopropyl ) glycine , and 3 , 5 - dihydroxyphenylglycine . exemplary antidepressants may include but are not limited to maprotiline , amitriptyline , clomipramine , desipramine , doxepin , imipramine , nortryptyline , protriptyline , trimipramine , ssris and snris such as fluoxetine , paroxetine , citalopram , escitalopram , sertraline , venlafaxine , fluoxamine , and reboxetine . exemplary antipsychotics may include but are not limited to clozapine , risperidone , quetiapine , olanzapine , amisulpride , sulpiride , zotepine , chlorpromazine , haloperidol , ziprasidone , and sertindole . exemplary mood stabilizers may include but are not limited to valproic acid ( valproate ) and its derivative ( e . g . divalproex ), lamotrigine , lithium , verapamil , carbamazepine and gabapentin . the following examples provided are not meant to limit the invention in any manner and are intended for illustrative purposes only . into a 1000 ml round - bottom flask equipped with a magnetic stirring bar and reflux condenser with a nitrogen inlet was charged with 25 . 0 grams ( g ) ( 0 . 1 10 mole ) of dibenzo [ b , f ][ 1 , 4 ] thiazepine - 11 ( 10 - h )- one ( made by the method disclosed by j . schmutz et al . helv . chim . acta ., 48 : 336 ( 1965 )), as a dry solid , followed by 310 ml pocl 3 and 3 ml of n , n - dimethylaniline . the reaction mixture was heated at reflux ( 106 degrees c .) for 6 hours giving a clear orange solution . the reaction was then cooled to room temperature , and pocl 3 removed on the rotary evaporator leaving an orange oil . this residue was partitioned between ice — water ( 500 ml ) and ethyl acetate ( 800 ml ). the layers were separated and the aqueous phase extracted with ethyl acetate ( 3 × 200 ml ). the combined ethyl acetate extracts were dried over mgso 4 , filtered , and then stripped down on the rotary evaporator , leaving the crude imino chloride as a light yellow solid ( 26 . 26 g , 97 % yield ). the structure was confirmed by nmr and mass spectrum ( 300 mhz , cdcl 3 ; es +, m + 1 = 246 . 7 ). crude imino chloride ( 27 . 35 g , 0 . 11 1 mole ) was added to 1000 ml o - xylene in a 2000 ml round - bottom flask equipped with a magnetic stir bar and a reflux condenser with nitrogen inlet . to this solution was added commercially available piperazine ( 47 . 95 g , 0 . 557 mole ) in one portion as a dry solid at room temperature . the mixture was stirred until nearly all the piperazine dissolved . then the reaction mixture was heated at reflux ( 142 degrees c ) for 40 hours ( out of convenience ). the reaction was then allowed to cool to room temperature , and an aliquot was partitioned between 1n naoh / ch 2 cl 2 . the organic phase was checked by tlc ( silica gel , ch 2 cl 2 / methanol 90 : 10 , iodoplatinate visualized ) and showed clean conversion to one major product ( rf = 0 . 45 ). a drop of the reaction solution was diluted with ch 3 cn to prepare a sample for lc / ms analysis , which confirmed the presence of the desired product ( m + 1 = 296 . 4 ). the reaction mixture was stripped down on the rotary evaporator under high vacuum to remove the xylene . the residue was partitioned between 1n naoh ( 400 ml ) and ch 2 cl 2 ( 200 ml ). the layers were separated , and the aqueous phase further extracted with ch 2 cl 2 ( 3 × 200 ml ). the combined ch 2 cl 2 extracts were washed with brine ( 200 ml ), then dried over mgso 4 , filtered , and stripped down on the rotary evaporator to give the crude title compound as a yellow gum ( 35 . 3 g ). the crude free base was purified by flash column chromatography over silica gel ( 600 g ) eluting with a gradient of 0 to 20 % methanol in ch 2 cl 2 . fractions containing the pure desired product were combined and stripped down on the rotary evaporator , to afford the purified free base as a light yellow foam ( 25 . 67 g , 78 % yield ). the free base was converted to it &# 39 ; s dihydrochloride salt by dissolving it in a mixture of methanol ( 125 ml ) and diethyl ether ( 125 ml ), then treating with 250 ml of 1 . 0 m hcl / ether ( aldrich ). an off - white gummy solid separated initially , and the mixture was further diluted with 500 ml ether . the gummy solid did not solidify on prolonged stirring . the solvents were decanted away from the gum . the gum was treated with absolute ethanol ( 200 ml ), then stirred until crystallization occurred , giving a thick white suspension of crystals . this mixture was then slowly diluted with ether ( 800 ml ) and allowed to stir overnight to complete the crystallization . the crystalline dihydrochloride salt was isolated by filtration , washed with ether ( 3 × 50 ml ), then dried in vacuum at 60 degrees c . to afford the dihydrochloride salt of the title compound as a white crystalline solid ( 31 . 64 g , 98 . 8 % conversion ). analysis : the product was characterized by nmr and lc / ms ( 300mhz , cdcl 3 ; ap +, m + 1 = 296 . 4 ). aqueous solution ( 584 ml ; e . g ., prepared by extraction of 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine into water / hcl from a toluene solution such as described below in preparation b ) containing 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine hydrochloride was charged to a jacketed 1 l flask . the flask was then charged with toluene ( 500 ml ) and sodium hydroxide ( 48 % w / w , 33 . 0 g ). the mixture was stirred at 70 ° c . for 30 minutes and became white and cloudy . the mixture was then allowed to settle for 30 min and the phases were separated . the toluene layer was washed at 70 ° c . with 2 × 100 ml of water ( 1 st wash = ph 10 . 3 ; 2 nd wash = ph 8 . 0 ). the final toluene volume was 560 ml containing about 74 g of 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine in good purity . the above procedure was repeated for an additional four aqueous solutions of 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine hydrochloride and the five resulting toluene solutions were combined and evaporated to dryness on a rotary evaporator . the resulting hard solid was then charged to a jacketed vessel and slurried with methyl - t - butyl ether ( mtbe ) ( 500 ml ). the resulting slurry was stirred overnight at ambient temperature and then cooled to 5 ° c . and held for 4 h . the solid 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine product was isolated on a no . 3 sinter and washed with 200 ml of cold mtbe . the cake was dried in a vacuum oven overnight at 60 ° c . yielding 373 g of product . a toluene solution of 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine ( 1500 ml , 0 . 686 mol ) prepared by reaction of piperazine with 11 - chloro - dibenzo [ b , f ][ 1 , 4 ]- thiazepine in toluene ( see , e . g ., u . s . pat . no . 4 , 879 , 288 ) was treated with 1500 ml deionized water and 90 ml of hcl ( 32 % w / w ). the resulting mixture was heated to 70 ° c . and agitated for 45 min . agitation was ceased and the mixture allowed to settle and phase separate for 30 min . the lower aqueous phase , containing the hcl salt of 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine was isolated . the aqueous phase was then treated with 1000 ml of toluene and 99 g of aqueous naoh ( 47 % w / w ). the resulting mixture was heated to 70 ° c . and agitated for 45 min . agitation was ceased and the mixture allowed to settle and phase separate for 30 min . the lower aqueous phase was discarded and the upper organic phase retained to which 300 ml of deionized water was added . the resulting mixture was agitated for 15 min and then allowed to settle for 30 min . the aqueous phase was discarded and the organic phase retained . the organic phase was extracted once more with 300 ml of deionized water . about 750 ml of toluene from the organic phase was distilled out . the resulting concentrate was cooled to 60 ° c ., then 200 ml of methyl - t - butyl ether ( mtbe ) was added . the resulting mixture was cooled to ambient temperature then seeded with form a seed crystals . the seeded mixture was then cooled to 10 ° c . and held at this temperature for 3 hours under slow agitation . the resulting solid was isolated under suction via a no . 3 sinter . the solid product was then washed with 120 ml of mtbe at ambient temperature and dried at 40 ° c . under vacuum resulting in 175 g ( 86 . 4 %) of crystalline product . assay 99 . 9 % w / w by hplc area solid 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine ( 30 g , 0 . 1016 mol ) prepared as described above was slurried in isopropanol ( 120 ml ). the resulting mixture was warmed to about 63 - 64 ° c . to completely dissolve the solid . the resulting solution was filtered through a preheated ( about 55 ° c .) split buchner funnel fitted with filter paper with a pore size of 6 μm . the filtered solution was then adjusted to 55 ° c . and seeded with seed crystals of form a ( 0 . 024 g ). the seeded solution was maintained at 55 ° c . for about 2 h then linearly cooled to 40 ° c . over the course of 6 h , linearly cooled to 20 ° c . over the course of 2 h , and then linearly cooled to 0 ° c . over the course of 1 h . the resulting slurry was held at 0 ° c . for 12 h and the solid product cake ( 13 mm high × 68 mm diameter ) was isolated by filtration . the product cake was displacement washed with 30 ml isopropanol prechilled to 0 ° c . and the cake allowed to deliquor . the product was then dried at 40 ° c . under vacuum yielding 24 . 9 g ( 83 %) of form a . assay by nmr : 98 . 9 % w / w . x - ray powder diffraction ( xrpd ) peak data of crystalline form a is provided below in chart a . the following instrument setting were used . instrument bruker d8 discover scan range 2 - 40 ° 2θ step size 0 . 007 ° 2θ scan speed 0 . 2 sec / step scan type 2th / t lamp intensity 35 kv / 45 ma in - vitro binding data for brain serotonin 5 - ht 2 , d1 and d2 receptors and in - vivo rat and mouse studies an assessment of dopamine antagonism was made in rodent models . the methods and procedures used can be found in j . med . chem ., 44 ( 3 ), 372 - 389 , 2001 and are incorporated herein by reference . the results are as follows the binding affinity for brain serotonin 5 - ht 2 receptor was 27 k 1 nm , and for dopamine d 1 and d 2 receptors was 1489 and 234 k 1 nm , respectively . these results show that the compound of the present invention as the dihydrochloride salt interacts with a broad range of neurotransmitter receptors , however , the assay also reveals that that the compound of the present invention as the dihydrochloride salt has a higher affinity for serotonin ( 5 - ht 2 ) receptors relative to dopamine ( d 2 ) receptors in the brain . it is this combination of serotonin and dopamine receptor antagonism , with higher relative 5 - ht 2 to d 2 receptor affinity that indicates that the compound of formula i or its pharmaceutically acceptable salts would act as a potent atypical antipsychotic . j . goldstein , quetiapine fumarate ( seroquel ): a new atypical antipsychotic , 35 ( 3 ) drugs of today 193 - 210 ( 1999 ). however , in vivo antipsychotic activity of 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine dihydrochloride was tested in mice ( p . o ) according to a standard apomorphine climbing mouse assay and in an rats ( freebase ) in a d - amphetamine locomotor activity test and the compound was not found to be efficacious in these models . differentiation of 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine from quetiapine is based on alpha receptor binding data shown below . receptor quetiapine affinity ( nm ) ( i ) affinity ( nm ) α1a 22 108 α1b 39 75 α1d — 185 α2c 28 . 9 820 the above affinity values were derived from the below results , methods and criteria . primary biochemical assay species conc . % inh . ic 50 ki n adrenergic α 1a rat 0 . 3 μm 51 0 . 268 ± 0 . 012 μm 0 . 108 ± 0 . 005 μm 1 . 03 ± 0 . 089 adrenergic α 1b rat 0 . 1 μm 50 0 . 136 ± 0 . 0154 0 . 075 ± 0 . 009 μm 1 . 1 ± 0 . 024 adrenergic α 1d hum 0 . 3 μm 53 0 . 377 ± 0 . 049 μm 0 . 185 ± 0 . 024 μm 0 . 984 ± 0 . 111 adrenergic α 2a hum 3 μm 51 2 . 82 ± 0 . 275 μm 1 . 06 ± 0 . 103 μm 0 . 969 ± 0 . 012 adrenergic α 2b hum 1 μm 62 0 . 451 ± 0 . 097 μm 0 . 206 ± 0 . 0445 μm 0 . 902 ± 0 . 055 adrenergic α 2c hum 10 μm 58 5 . 64 ± 1 . 01 μm 0 . 82 ± 0 . 146 μm 1 . 1 ± 0 . 079 adrenergic α 1 * rat 0 . 1 μm 61 0 . 0693 μm 0 . 0372 μm 0 . 964 adrenergic α 2 * rat 10 μm 73 1 . 41 μm 1 . 29 μm 0 . 592 203100 adrenergic α 1a source : wistar rat submaxillary gland ligand : 0 . 25 nm [ 3 h ] prazosin vehicle : 1 % dmso incubation time / temp : 60 minutes @ 25 ° c . incubation buffer : 20 mm tris - hcl , 0 . 5 mm edta , ph 7 . 4 non - specific ligand : 10 μm phentolamine k d : 0 . 17 nm * b max : 0 . 18 pmole / mg protein * specific binding : 90 % * quantitation method : radioligand binding significance criteria : ≧ 50 % of max stimulation or inhibition 203500 adrenergic α 1 * non - selective source : wistar rat brain ligand : 0 . 25 nm [ 3 h ] prazosin vehicle : 1 % dmso incubation time / temp : 30 minutes @ 25 ° c . incubation buffer : 50 mm tris - hcl , 0 . 1 % ascorbic acid 10 μm pargyline non - specific ligand : 0 . 1 μm prazosin k d : 0 . 29 nm * b max : 0 . 095 pmole / mg protein * specific binding : 90 % * quantitation method : radioligand binding significance criteria : ≧ 50 % of max stimulation or inhibition these results show that 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine has lower affinity than quetiapine to the al and a2 adrenergic receptors . cho membranes ( 10 μg protein ) expressing human 5 - ht 1a receptors were incubated in 100 μl of 20 mm hepes , ph 7 . 4 assay buffer containing 10 mm mgcl 2 , 100 mm nacl , 0 . 1 % bsa , 20 μm gdp , 200 μg wga - pvt beads ( amersham rpnq0001 ), 200 μm gtpγ 35 s ( perkin elmer neg - 030h ). 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine was incubated with the above at 11 different concentrations varying from 10 μum to 170 pm in packard optiplates with shaking for 1 . 5 hrs at room temperature . 5 - ht was used as a positive control , with an ec50 15 . 5 nm in the assay . one μm of 5 - ht was used as maximum agonist activity ( 100 %) for the compound efficacy determination . the plates were centrifuged to settle the beads and measured in a parkard topcount . using this assay , 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine is shown to be a partial agonist of 5ht 1a receptor with an ec50 of 310 nm and a maximum efficacy of 66 % relative to 1 μm of 5 - ht . 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine was administered to 3 sprague - dawley rats each either intravenously or orally at doses of 10 umol / kg or 30 umol / kg , respectively , in a sodium citrate ( ph 3 ) formulation . blood samples were removed from each animal at several timepoints after dosing . the blood samples were centrifuged to produce plasma . aliquots of each plasma sample were analyzed by an hplc method with mass spectrometric detection to measure 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine . the area under the plasma concentration curves ( auc ) constructed from the sample measurements following iv or po administration were used to calculate oral biovailability . the calculated oral bioavailability based on the results of this study was 11 % for rat . a similar study design ( different doses for oral and iv administration ) was used to calculate oral bioavailability in beagle dogs ( 42 %) and cynomolgus monkeys ( 37 %). hence , 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine is shown to be orally bioavailable in three species . brain exposure was measured in rats . for concentrations of 11 - piperazin - 1 - yldibenzo [ b ][ 1 , 4 ] thiazepine in brain , rats were dosed either po or iv ( n = 3 per dose route ). at one hour after compound administration , blood and brain samples were obtained and then processed for analysis using hplc / ms to measure concentrations of 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine . average concentrations in rats one hour after oral dosing at 30 umol / kg po was 658 nmol / ml plasma and 2240 nmol / g brain tissue , giving a brain / plasma exposure ratio of 3 . 4 . a similar analysis after iv dosing measured brain : plasma concentration ratios of 4 . 6 demonstrating penetration of the compound into the cns . antidepressant effects of 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine in the mouse forced swim test : a comparison to quetiapine the mouse forced swim test ( fst ) has been used to assess antidepressant potential of novel compounds ( porsolt ; lucki ). methods : mice were placed in cylinders of water ( 25 . 0 ° c .± 1 . 5 ° c .) for 6 min . the amount of immobility was quantified during the last 4 min of each session . the experimental observer was blind to the treatment conditions . 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine ( 5 . 0 and 10 . 0 mg / kg ) and quetiapine ( 5 . 0 , 10 . 0 , and 20 . 0 mg / kg ) were measured as the base and administered sc 15 min prior to the behavioral session . imipramine 45 . 0 mg / kg and citalopram 15 . 0 mg / kg were measured as the salt and administered ip 60 min prior to the behavioral session . results : 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine ( 10 . 0 mg / kg ) had antidepressant effects in this assay comparable to imipramine . quetiapine had no effect in the fst at the doses tested . these data suggest that 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine but not quetiapine has an antidepressant profile . antidepressant activity of 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine was assessed in mice according to the tail suspension test . as shown in the results below , 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine has antidepressant activity in mice . in a first experiment , mice ( n = 10 / group ) were treated with vehicle , 2 . 0 , 5 . 0 , or 10 . 0 mg / kg of 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine s . c . 15 minutes prior to the test session . mice were suspended from their tails for 7 minutes . during the last 5 min of the test , the duration of immobility was recorded . in a second experiment , mice ( n = 10 / group ) were treated with vehicle , 30 mg / kg 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine , or 30 mg / kg fluoxetine p . o . 60 minutes prior to the test session . mice were suspended from their tails for 7 minutes . during the last 5 minutes of the test , the duration of immobility was recorded . results of the first experiment showed that 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine reduced immobility at all doses tested . the dose at 10 . 0 mg / kg significantly reduced immobility compared with controls , p & lt ; 0 . 01 , reducing immobility by more than ½ that of the vehicle control group . results of the second experiment showed significant main effect of treatment for the dose tested ( f ( 2 , 27 )= 8 . 391 ). both 11 - piperazin - 1 - yldibenzo [ b , f ][ 1 , 4 ] thiazepine and fluoxetine at 30 mg / kg significantly reduced immobility compared to the vehicle control group , p &# 39 ; s & lt ; 0 . 01 , reducing immobility by more than ½ that of the vehicle control group . various modifications of the invention , in addition to those described herein , will be apparent to those skilled in the art from the foregoing description . such modifications are also intended to fall within the scope of the appended claims .
a method of treating at least one symptom or condition associated with but not limited to : mood disorders including but not limited to a ) depressive disorders , including but not limited to major depressive disorder and dysthymic disorder and b ) bipolar depression and / or bipolar mania including but not limited to bipolar i disorder , including but not limited to those with manic , depressive or mixed episodes , and bipolar 11 disorder , c ) cyclothymic disorder , and d ) mood disorder due to a general medical condition comprising administering an effective amount of formula i or its pharmaceutically acceptable salt . in another aspect of the invention a pharmaceutical composition is provided comprising an effective amount of formula i or its pharmaceutically acceptable salt and at least one pharmaceutically acceptable carrier or diluent .