药剂学新剂型-201312282995课件

1、Introduction of oral sustained-release and controlled-release formulationsSpecialty:pharmaceuticsStudent ID：201312282995The basic definition of sustained-release and controlled-release formulationssustained-release formulations The preparation of the drug can for a long time sustained release drug t

2、o achieve long-lasting effect,the drug release was first-order rate process.controlled-release formulations The drug at a predetermined time automatically at a predetermined rate of release,the blood concentration for a long time constant to maintain in the effective concentration range,the drug rel

3、ease was zero-order or near zero-order rate process.The blood concentration-time chart of controlled-release formulations and general formulations Characteristics of sustained-release and controlled-release formulationsAdvantagesExtended dosing interval,reduce the administration frequency,Improving

4、medication compliance.The blood concentration is stable,avoid peak valley phenomenon,reduce the adverse effect.Lower gastrointestinal irritation.Improve the bioavailability of drugs.Reduce the total dose administered.DisadvantagesAdjustment of the dose in the clinical application of lower flexibilit

5、y,if a particular condition,often do not immediately stop treatment.These preparations is designed based on the mean kinetic parameters in healthy people,when the in vivo dynamics characteristic of drugs in the disease state change,can not flexibly adjust the dosing regimen.Higher production costs s

6、uch these preparations,complex preparation process.Dissolution mechanismNoyes-whitney dissolution rate equation：By reducing the solubility of drugs,increasing the particle size of the drug,reduce the dissolution rate of the drug,allows slow release of the drug.The specific methodsMade of low solubil

7、ity salts or esters.With the high molecular compound to form insoluble salts.Control of particle size.Diffusion mechanismControl of membrane materials:diffusion through the membrane.The porous membrane controlled:membrane pore diffusion.Channel controlled:skeletal material diffuses.The specific meth

8、odsCoating.Made microcapsules,microspheres.Made insoluble matrix tablets.Increase the viscosity to reduce the rate of diffusion.Made emulsions.Osmotic pressure mechanismThe core is made of water soluble medicine and water soluble polymer and osmotic agent,covering a similar semipermeable membrane co

9、ating,in the one-sided laser drilling one or both.Water through a semipermeable membrane into the tablet core,the drug is dissolved to saturation,as the osmotic pressure difference leads to drug solution flows out from the hole in the laser.Such a system independent of the nature of drug release,the

10、 disadvantage is the higher cost,and the drug instability of the solution is not applicable.Ion exchange mechanismThe water-insoluble resin is composed of crosslinked polymer,repeating unit of the polymer chain containing salt forming group,drugs can be combined with the resin.When the ion and ion w

11、ith appropriate charge exchange group contact,through the exchange of the free drug release.Diffusion of the drug from the resin by the diffusion rate of the area, control the diffusion path length and rigidity of the resin.Classification of sustained-release and controlled-release formulationsSkele

12、ton-type sustained-release formulationsMembrane-controlled sustained-release formulationsOsmotic pump controlled-release formulationsGastric Retention sustained-release formulationsSchematic diagram of three kinds of matrix tablets drug release processMembrane-controlled sustained-release formulatio

13、nsMicroporous film-coated tablets:existence of the coating film pore forming agent dissolved in water or fall off,the formation of numerous pores or curved path on the coating film,slow release of the drug.Membrane controlled-release small tablets:the drug and excipients according to conventional me

14、thods of granulating pressing die,diameter of about 3mm,with the sustained release film coating after filling in the hard capsule.Enteric coated membrane controlled-release tablets:drug tablet cores outsourcing enteric-coated,and coated with drug-containing layer of sugar-coating,sugar-coating layer

15、 containing the drug release in the stomach,enteric coated tablets film into the intestines dissolved,drug release from the cores.Gastric Retention sustained-release formulationsCan float on gastric fluid retention,extended drug release in the digestive tract.Generally up to 5 to 6 hours stranded in

16、 the stomachRetention methodsUse less dense matrix material:Stearyl alcohol,Cetyl alcohol etc.Parcel of air or using effervescent technologyMechanical retentionReferenceF.D. Cui,X.Y.Long.pharmaceuticsM.Beijing:Peoples Medical Publishing House,2011:418-419.Khan ZA,Tripathi R,Mishra B. Floating elemen

17、tary osmotic pump tablet( FEOPT) for controlled delivery of diethylcarbamazine citrate: a water-soluble drugJ.AAPS Pharm Sci Tech,2011,12( 4) :1312-1323.Pandey S,Viral D.Osmotic pump drug delivery devices:from implant to sandwiched oral therapeutic systemJ. International Journal Pharmaceutics Techno

18、logy Research,2010,2(1):693 -699.Siepmann F,Hoffmann A,Leclercq B,et al.How to adjust desired drug release patterns from ethylcellulose-coated dosage formsJ.Journal of Controlled Release,2007,119(2):182-189.Islam MS, Azam KR,Chowdhury JA,et al.Comparison of gastro retention time and in vitro release profile studies of ciprofloxacin HCl from