1. IIUM Research, Invention and Innovation Exhibition 2011 ‘ Enhancing Quality Research and Innovation for Societal Development’ Farahidah Mohamed, Ahmad Fahmi Harun Ismail and Abd Almonem Doolaanea Department of Pharmaceutical Technology, Faculty of Pharmacy, International Islamic University of Malaysia, 25200 Kuantan Campus, Malaysia. Phone: 09-571-6400 Fax: 09-571-6775 E-mail: farahidah@iiu.edu.my ID 3 0 2 MICROENCAPSULATION OF DRUG INTO BIODEGRADABLE POLYMER AS A NOVEL DRUG DELIVERY SYSTEM Abstract Summary This study was done to observe the effects on the development of Gentamicin- loaded PLGA microspheres based on several parameters named as PVA concentration (1%, 2%, 3%, 4% and 5%), types of surfactant which were Span 80, Span 85, Tween 20, Tween 80, Triton X100 as well as the combination between Span and Tween. The molecular weight of PLGA was also one of the parameters used which were 0.2, 0.4 and 1.0 dL/g. The values for HLB according to the surfactants used were manipulated to get certain level (4, 10, 13.5 and 16) to observed the effects on the particle size of microspheres that were fabricated. The microspheres were fabricated using double-emulsion solvent evaporation method and the above said parameters were used as the independent variables where they were applied. The particle size of fabricated micropsheres for every batch was measured using the laser diffraction and the size less than 10 µm was preferable. The images of micropsheres were taken using the SEM at different resolutions to observe the external morphology as well as the shape. Objectives 1.To fabricate microspheres loaded with Gentamicin using double-emulsion solvent evaporation method by using PLGA 50:50. 2.To investigate the effects on particle size of microspheres against different parameters i.e different MW of PLGA, the type of surfactants used, the HLB values and also the different concentrations of PVA. 3.To study the external morphology as well as the shape of fabricated micropsheres using SEM. Introduction Mycoplasma pulmonis is one of the major causes for arthritis which can be treated with Gentamicin. The conventional way of administrating Gentamicin is by giving in a repeated doses for certain period of time to maintain the bioavailibility of the active ingredient to treat the illness. By using microspheres loaded with Gentamicin, it is believed that the delivery the drug i.e Gentamicin can be maintained in a certain period of time without having to administer multiple doses of drug. The size of less than 10 µm of the fabricated microspheres containing Gentamicin is the most preferable. The external morphology as well as the shape of the micropsheres are observed here as a more efficient method of delivering Gentamicin as well as to carry the drug to the target area effectively. Research Methodology This is the schematic diagram of the procedure to fabricate Gentamicin- loaded PLGA microspheres #€ Ω ∆ Homogenized at 14,500 rpm for 1 min Directly injected into Aqueous 2 Homogenized at 14,500 rpm for 3 min Directly poured Continuously stirred Hardening tank Hardened microspheres were washed, collected and lyophilized. # Oil Phase which composed of PLGA, DCM and Surfactants € Aqueous 1 containing Gentamicin Ω Primary emulsion (w/o) ∆ Aqueous 2 (secondary emulsion) which composed of different concentration of PVA * Microspheres of 1% PVA (scale bar= 2 µm) * Microspheres of HLB 10 (scale bar= 10 µm) * Microspheres of Triton X100 (scale bar= 2 µm) Microspheres of Span 80 + Span 85 (scale bar= 2 µm) * Microspheres of 5% PVA (scale bar= 2 µm) * Microspheres of 3% PVA (scale bar= 10 µm) These are some of the SEM images showing clearly the external morphologies of the micropsheres according to the parameters used i.e the PVA concentration. The images also show the spherical shape of the micropsheres fabricated with Gentamicin. The images were taken at different resolutions and depth. Please refer to the scale bar to get better perspective on the particle size of respective microspheres. Result & Discussion * Microspheres of HLB 4 (scale bar= 2 µm) * Microspheres of HLB 13.5 (scale bar= 2 µm) PVA Conc. (%)12345 Particle size (µm) (mean ± S.D); n=3 11.7 ± 0.62 9.26 ± 0.03 5.56 ± 0.05 3.78 ± 0.01 3.36 ± 0.01 For PVA concentration, it shows clear reduction pattern of the diameter size of microspheres as the PVA concentration is increases. The PVA concentration used gives inverse proportion to the particle size. SurfactantSpan 80+85 Tween 20+80 Triton X100 Span 80 + Tween 80 Particle size (µm) (mean ± S.D); n=3 15.97 ± 0.21 10.53 ± 0.15 12.07 ± 0.12 9.55 ± 0.07 HLB value41013.516 Particle size (µm) (mean ± S.D); n=3 7.16 ± 0.03 5.12 ± 0.03 4.16 ± 0.02 3.96 ± 0.23 In the case of HLB value, as the value is increasing, the hydrophilicity of the surfactant MW of PLGA (dl/g)0.20.41.0 Particle size (µm) (mean ± S.D); n=3 9.55 ± 0.07 11.02 ± 0.03 12.20 ± 0.01 As the molecular weight increases, the particle size is also increases. The higher molecular weight of PLGA means more viscous the oil phase will be. So the particle increases. The microspheres tend to form smaller particles due to the result known as reverse miscelle. Conclusion The particle size of Gentamicin-loaded PLGA microspheres is very much affected by all the parameters studied. The combination of the parameters i.e higher concentration of PVA with lower MW of PLGA used is believed to give smaller particle size. Fabrication of microspheres using the combination of these parameters is a promising way to obtain particle size less than 10 µm. size is increases. Other than that, the water solubility will decrease as the molecular weight is increases. Hence, the particle size will also increase. Acknowledgement A great gratitude goes to Allah for His will, to Kulliyyah of Pharmacy of IIUM for providing the place to conduct the research. To RMC of IIUM for the research grant (EDW-B10100-0439) and to those directly or indirectly involved with the research.