Part1pharmacologyTheword“pharmacology”derivesfromtheGreekwordfordrug,pharmakon.Itisthebranchofmedicineandbiologyconcernedwiththestudyoftheactions,uses,mechanisms,andadverseeffectsofdrugs.Morespecifically,itisthestudyoftheinteractionsthatoccurbetweenalivingorganismandchemicalsthataffectnormalorabnormalbiochemicalfunction.Ifsubstanceshavemedicinalproperties,theyareconsideredpharmaceuticals.Thefieldofpharmacologyencompassesdrugcompositionandproperties,interactions,toxicology,therapy,andmedicalapplicationsandanti-pathogeniccapabilities.Thetwomainareasofpharmacologyarepharmacodynamicsandpharmacokinetics.Theformerstudiestheeffectsofthedrugsonbiologicalsystems,andthelatterstudiestheeffectsofbiologicalsystemsonthedrugs.Inbroadterms,pharmacodynamicsdiscussestheinteractionsofchemicalwithbiologicalreceptors,andpharmacokineticsdiscussestheabsorption,distribution,metabolism,andexcretionofchemicalsfromthebiologicalsystems.Pharmacokineticsdescribestheeffectofthebodyonthedrug.Whendescribingthepharmacokineticpropertiesofadrug,pharmacologistsareofteninterestedinLADME:Liberation-disintegration,dispersalanddissolutionAbsorption-Isthemedicationabsorbedthroughtheskin,theintestine,ortheoralmucosaDistribution-Howdoesitspreadthroughtheorganism?Metabolism-Isthemedicationconvertedchemicallyinsidethebodyandintowhichsubstances?Aretheseactive?Couldtheybetoxic?Excretion-Isthemedicationeliminatedthroughthebile,urine,breath,orskin?Pharmacologyisnotsynonymouswithpharmacyandthetwotermsarefrequentlyconfused.Pharmacologydealswithhowdrugsinteractwithinbiologicalsystemstoaffectfunction.Itisthestudyofdrugs,ofthereactionsofthebodyanddrugoneachother.Incontrast,pharmacyisabiomedicalscienceconcernedwithpreparation,dispensing,dosage,andthesafeandeffectiveuseofmedicines.Thestudyofpharmacologyisofferedinmanyuniversitiesworldwideinprogramsthatdifferfrompharmacyprograms.Studentsofpharmacologyaretrainedasresearchers,studyingtheeffectsofsubstancesinordertobetterunderstandthemechanismswhichmightleadtonewdrugdiscoveries.Whereasapharmacystudentwilleventuallyworkinapharmacydispensingmedicationsorsomeotherpositionfocusedonthepatient.Part2PharmaceuticalchemistryMedicinalorpharmaceuticalchemistryisadisciplineattheintersectionofchemistryandpharmacology,andinvolvestheidentification,synthesisanddevelopmentofnewchemicalentitiessuitablefortherapeuticuse.Thecontentofmedicinalchemistryalsoincludesthestudyofexistingdrugs,theirchemicalstructure,physicalandchemicalproperties,chemicalstability,biologicalproperties,structure-activityrelationships(SAR),metabolism,chemicalmechanismofinteractionbetweendrugsandbiologicaltarget,etc.Thescienceofmedicinalchemistryinvolvesthedesignandsynthesisofnoveldrugs.Therearetwomajorconsiderationsthathavetobetakenintoinanydrugdesignproject.Firstofall,drugsinteractwithmoleculartargetsinthebody,andsoitisimportanttochoosethecorrecttargetforthedesiredpharmaceuticaleffect.Itisthenacaseofdesigningadrugwillinteractaspowerfullyandselectivelyaspossibleforthattarget–anareaofmedicinalchemistryknownaspharmacodynamics,Secondly,adrughastotravelthroughthebodyinordertoreachitstarget,soitisimportanttodesignthedrugsothatitisabletocarryoutthatjourney.Thisisanareaknownaspharmacokinetics.Thechiefroleofthemedicinalchemististodesignandsynthesizethetargetstructuresrequired.Therefore,themedicinalchemistisanessentialmemberofanydrugdesignteamsinceheorshehastoidentifywhetherproposedtargetstructuresarelikelytobestableandwhethertheycanbesynthesizedornot.Inmedicinalchemistry,thesearchofleadcompoundanditsstructuralmodificationareimportanttwostepsforlookingfornewdrugs.Theleaddiscoveryprocessesincluderandomscreening,drugmetabolismstudies,clinicalobservationsofdrugaction,rationalapproachestoleaddiscoveryandcomputer-assisteddrugdesigntechniques,etc.Manyapproachescanbeusedforoptimizationofleadcompound,suchasleadoptimizationbypro-drugdesign,bybioisosterism,bysoftdrugorharddrugdesign,byQSARmethod,etc.Computeraideddrugdesign(CADD),asophisticdrugdiscoveringtechniques,isatopicareainmodernmedicinalchemistryforthediscoveryofleadcompoundanditspharmaceuticaldevelopment.Part3PharmaceuticsPharmaceuticsisabranchofpharmacyofstudyinghowtogeteffectiveandstablepharmaceuticaldosageformswithoutdisturbingitsqualitybythesystematicapproach.Primitively,itisconcernedwiththescientificandtechnologicalaspectsofthedesignandmanufactureofdosageforms.Meanwhile,pharmaceuticsisthescienceofdrugdeliverysystemforseekingtheoptimaldrugdeliveryproductordeviceanditssubsequentperformanceinthedeliveryofthedrugformsfollowingitsadministrationtoapatient.Thestudyinvolvespreparationandstabilityofsuitabledosageforms,designandmanufactureofdosageformsthatovercomethephysiologicbarrierandoptimizethedrugaction,quantitativecharacterizationofboththedrugconcentration-effectrelationshipandtheconcentration-timerelationshipafterthedrugentersthebodyandevaluatingthedosageregimen,avoidanceandeliminationofmicroorganismsinthemedicines.Pharmaceuticsisamultidisciplinaryarea,withsignificantunderpinningsfromsuchbasicscientificdisciplinesasphy