Microspheres ppt

In this ppt ,i have covered the introduction of microspheres,various preparation methods of microspheres, advantages and disadvantage of microspheres,types and evaluation parameters of the microspheres.

1. MOLECULAR PHARMACEUTICS (MICROSPHERES) Presented by : Gutte Vaishali Pundlik Roll no : 05 M pharm (Pharmaceutics) Under Guidance Of : Proff.Shraddha Tiwari Mam DAYANAND COLLEGE OF PHARMACY, LATUR July 1 5 , 2022

2. CONTENT : Introduction of microspheres Advantages Disadvantages Polymers used in microspheres Types Preparation Evaluation Reference DAYANAND COLLEGE OF PHARMACY, LATUR

3. INTRODUCTION: Microspheres: Microspheres are small spherical particles, with diameter 1 μm to 1000 μm . They are spherical free flowing particles consisting of proteins or synthetic polymers which are biodegradable in nature. DAYANAND COLLEGE OF PHARMACY, LATUR

4. ADVANTAGES: Improve bioavailability Provide constant and prolonged therapeutic effect. Provide constant drug concentration in blood . Decrease dose and toxicity. Protect the drug from enzymatic and photolytic cleavage so it is best for drug delivery of protein. Reduce the dosing frequency and thereby improve the patient compliance DAYANAND COLLEGE OF PHARMACY, LATUR

5. DISADVANTAGES: The cost is more. Reproducibility is less. Process conditions like change in temperature, pH, solvent addition, and evaporation/agitation may influence the stability of core particles. Degradation of product due to heat, hydrolysis, oxidation, solar radiation or biological agents. DAYANAND COLLEGE OF PHARMACY, LATUR

6. POLYMERS USED : 1) Synthetic polymers: a) Non – biodegradable: Poly methyl methacrylate (PMMA),Acrolein,Glycidyl methacrylate,Epoxy polymers. b) Biodegradable: Lactides,Glycolides,poly alkyl cyanoacrylates,poly anhydrides 2) Natural polymers: a) Proteins : Albumin,Gelatin, Collagen b) Carbohydrates: Agarose,Carrageenan,Chitosan,Starch c) Chemically modified carbohydrates : Poly dextran,Poly starch DAYANAND COLLEGE OF PHARMACY,LATUR

7. TYPES OF MICROSPHERES: Bioadhesive microspheres Floating microspheres Radioactive microspheres Magnetic microspheres Polymeric microspheres i)Biodegradable polymeric microspheres ii)Synthetic polymeric microspheres DAYANAND COLLEGE OF PHARMACY, LATUR

8. 1.Bioadhesive Microspheres : Adhesion of drug delivery device to the mucosal membrane such as buccal, ocular, rectal , nasal etc. Can be termed as bio adhesion. These kinds of microspheres exhibit a prolonged residence time at the site of application and causes intimate contact with the absorption site and produces better therapeutic 2.Floating Microspheres : In floating types the bulk density is less than the gastric fluid and so remains buoyant in stomach without affecting gastric emptying rate. The drug is released slowly at the desired rate, and the system is found to be floating on gastric content and increases gastric residence and increases fluctuation in plasma concentration. Moreover it also reduces chances of dose dumping. It produces prolonged therapeutic effect and therefore reduces dosing frequencies. DAYANAND COLLEGE OF PHARMACY, LATUR

9. 3. Radioactive Microspheres : Radioactive microspheres Deliver high radiation dose to targeted site without damaging the normal surrounding tissues.Diagnostic: Applicabe for cancer therapies .ex., in case of Liver , spleen .Radioactive microspheres are alpha emitters,beta emitters and gamma emitters. 4 .Magnetic Microspheres : Magnetic microspheres Localize the drug to the disease site. In this larger amount of freely circulating drug can be replaced by smaller amount of magnetically targeted drug. Magnetic carriers receive magnetic responses to a magnetic field from incorporated materials that are used for magnetic microspheres are chitosan,dextran etc. These magnetic microspheres are used to deliver chemotherapeutic agents to liver tumor Drugs like proteins and peptides can also be targeted through this system. DAYANAND COLLEGE OF PHARMACY, LATUR

10. 5.Polymeric Microspheres : The various types of polymers are used for preparation of microspheres e.g:- Albumin microspheres , Gelatin microspheres , Starch microspheres , Dextran microspheres , Carrageenan Polymeric microspheres are classified as : a.Biodegradablee polymeric microspheres: - Natural polymers such as starch are used with the concept that they are biodegradable, biocompatible,and also bioadhesive in nature. Biodegradable polymers prolongs the residence time when contact with the mucous membrane due to its high degree of swelling property with aqueous medium. The rate and extent of drug release is controlled by concentration of polymers. b. Synthetic polymeric microspheres:- Widely used in clinical applications. , Alginate microspheres . DAYANAND COLLEGE OF PHARMACY, LATUR

11. METHODS OF PREPARATION: 1. Solvent evaporation method 2. Emulsion cross linking method 3. coacervation/ phase separation method 4. spray drying method 5. Emulsion – solvent diffusion method 6. Multiple emulsion method 7. Ionic gelation method DAYANAND COLLEGE OF PHARMACY, LATUR

12. 1.SOLVENT EVAPORATION METHOD : Core material ↓Dissolved or dispersed coating polymer solution ↓Agitation core material disperse in liquid manufacturing vehicle paste ↓Heating,if needs evaporation of polymer solvent ↓ microspheres DAYANAND COLLEGE OF PHARMACY, LATUR

13. 2.EMULSION CROSS LINKING METHOD: Aq. Solution / suspension polymer ↓ Dispersion in organic phase oil ↓ 1. Heat denaturation 2. by chemical cross linking microspheres in organic phase ↓ centrifugation,wash, separation microspheres DAYANAND COLLEGE OF PHARMACY, LATUR

14. 3.PHASE SEPARATION COACERVATION METHOD: Aq. / organic solution of polymer ↓ Add drug Drug dispersed or dissolved in the polymer solution ↓phase seperation induced by different means Polymer rich globules ↓solidify Microspheres in aq./ organic phase ↓separate,wash,dry Microspheres. DAYANAND COLLEGE OF PHARMACY, LATUR

15. 4.SPRAY DRYING/CONGEALING METHOD: Polymer dissolved in volatile organic solvent (acetone) ↓ Drug dispersed in polymer solution under high speed homogenization ↓ Atomized in a stream of hot air ↓ Solvent evaporation of small droplets leads to formation of microspheres ↓ Microspheres separated from hot air by colone separator and trace of solvent are removed by vaccum drying. DAYANAND COLLEGE OF PHARMACY, LATUR

16. 5.EMULSION SOLVENT DIFFUSION METHOD: Drug + Lipophilic surfactant ↓ Dissolve in water miscible solvent ↓ Add into aqueous surfactant ↓ Stirring ↓ High pressure homogenization ↓ Diffusion of the solvent ↓ Formation of microspheres DAYANAND COLLEGE OF PHARMACY, LATUR

17. 6.MULTIPLE EMULSION METHOD: Polymer in aq. Solution + drug ↓Homogenization / sonication Disperse in organic phase ↓ Primary emulsion ↓Addition of aq. Solution of PVA Multiple emulsion ↓Addition to large aq. Phase Microspheres in solution ↓separation,wash,dry Microspheres DAYANAND COLLEGE OF PHARMACY, LATUR

18. 7.IONIC GELATION METHOD: Sod. Alginate + Water ↓stirred+drug + cal.carbonate Cal.chloride + 2 % Glacial acetic acid ↓ The gel microspheres formed in solution ↓stirred for 30 min at room temperature Microspheres are collected,washed,dried DAYANAND COLLEGE OF PHARMACY, LATUR

19. EVALUATION: Particle shape and size Degradation behaviour Angle of repose Bulk density Tapped density Drug entrapment efficiency Swelling index In vitro methods Adhesion property DAYANAND COLLEGE OF PHARMACY, LATUR

20. Particle size and shape: The most widely used procedures to visualize microparticles are conventional light microscopy (LM) and scanning electron microscopy (SEM). Degradation behavior: The surface chemistry of the microspheres can be determined using the electron spectroscopy for chemical analysis (ESCA). Angle of repose: The powder mass was allowed to flow through the funnel orifice kept vertically to a plane paper kept on the horizontal surface, giving a heap angle of powder on paper. The angle of repose was calculated by the following equation tan θ =h/r Where, h & r are the height and radius of the powder cone. DAYANAND COLLEGE OF PHARMACY, LATUR

21. Bulk density: Bulk density was obtained by dividing the mass of powder by the bulk volume in cm3. It was calculated by using equation: Bulk density = mass of microspheres / bulk volume Tapped density: It is the ratio of total mass of the powder to the tapped volume of the powder. It is expressed in g/ml and is given by : Tapped density = mass of microspheres /Tapped volume. . Drug entrapment efficiency: It is the percentage of drug that is successfully entrapped with in microspheres . Drug entrapment efficiency can be calculated using following equation , % Entrapment = Actual content / Theoretical content x 100 DAYANAND COLLEGE OF PHARMACY, LATUR

22. Swelling index : It is conducted in a phosphate buffer of pH 6.8.Their diameter is measured periodically by using laser particle size distribution analyzer until they were decreased by erosion and dissolution. Swelling index= (mass of swollen microspheres – mass of dry microspheres/mass of dried microspheres) 100 8) In vitro methods: Release studies for different type of microspheres are carried out by using phosphate buffer pH 7.4, mostly by rotating paddle apparatus. Agitated with 100 rpm, samples were collected at specific time intervals and replaced by same amount and analyzed. 9) Adhesion property: Freshly cut piece of pig intestine is used (5 cm long),clean and wash it with isotonic saline solution. DAYANAND COLLEGE OF PHARMACY, LATUR

23. CONCLUSION: Microspheres are having wide applications in drug delivery systems. Most important are the targeted drug delivery ,Controlled and sustained drug delivery .By combining various strategies, microspheres will find central place in novel drug delivery mainly particularly in cell sorting, diagnostics and Genetic engineering. DAYANAND COLLEGE OF PHARMACY, LATUR

24. REFERENCES: PV .A TEXT BOOK OF MOLECULAR PHARMACEUTICS.PAGE NO. 85 - 97 Https://www.slideshare .net/ Sowjanyareddy 14019338. REVIEW ARTICLE FROM INTERNATIONAL JOURNAL OF CURRENT PHARMACEUTICAL RESEARCH, BY KUMAR DAS,ABDUL BAQEE AHMED,DIPANKAR SAHA. DAYANAND COLLEGE OF PHARMACY, LATUR