Indian J.Pharm. Educ. Res. 44(1), Jan-Mar, 2010

Size: px

Start display at page:

Download "Indian J.Pharm. Educ. Res. 44(1), Jan-Mar, 2010"

Juliana Atkinson
5 years ago
Views:

1 Enhancement f Disslutin Rate f Glimepiride using Slid Dispersins with Plyvinylpyrrlidne K 90 S. S. Mhanty, Subhasish Biswal, S. Biswal*, J. Sah, A. K. Mahapatra and P. N. Murthy Ryal Cllege f Pharmacy and Health Sciences, Andhapasara Rad, Berhampur , Orissa, India * Crrespnding authr: sudarsan_mpharm@yah.c.in Abstract The aim f the present study was t enhance the disslutin rate f glimepiride using its slid dispersins (SDs) with plyvinylpyrrlidne K 90. The phase slubility behavir f glimepiride in presence f varius cncentratins f plyvinylpyrrlidne K 90 in phsphate buffer ph 7.4 was btained at 37 C. The slubility f glimepiride increased with increase in amunt f plyvinylpyrrlidne K 90 in buffer ph 7.4. Gibbs free energy (ÄG tr) values were all negative. The slid dispersins f glimepiride with plyvinylpyrrlidne K 90 were prepared at 1:1, 1:3 and 1:5 (glimepiride: PVPK 90) rati by kneading methd. Evaluatin f the prperties f the slid dispersins was perfrmed by using disslutin, Furier-transfrm infrared (FTIR) spectrscpy and X-ray diffractin (XRD) studies. The slid dispersins f glimepiride with plyvinylpyrrlidne K 90 exhibited enhanced disslutin rate f glimepiride. The mean disslutin time (MDT) f glimepiride decreases significantly in slid dispersins. The Furier-transfrm infrared spectrscpic studies shwed frmatin f intermlecular hydrgen bnding between glimepiride and plyvinylpyrrlidne K 90. The X-ray diffractin studies indicated the partially amrphus state f glimepiride in SD f glimepiride with plyvinylpyrrlidne K 90. Keywrds: Glimepiride, plyvinylpyrrlidne K 90, slubility, disslutin rate INTRODUCTION Glimepiride, 1-(p-(2-(3-ethyle-4-methyl-2-x-3- pyrrline-1-carbxamid) ethyl) phenyl) sulfnyl)-3- (trans-4-methylcyclhexyl) urea is a third generatin f hypglycemic sulfnylurea which is useful in the treatment f nn-insulin dependent diabetes mellitus 1, 2 (NIDDM). Prir reprts reveal that the drug shws mre ptential benefits ver currently available sulfnylureas such as lwer dse, rapid nset f actin, lnger duratin f actin and lwer insulin C-peptide 3, 4 level. Glimepiride is a white crystalline pwder, relatively insluble in water (pka=6.2). Glimepiride exhibits slw GI absrptin rate and inter individual variatins in its biavailability due t its pr water 1, 5, 6 slubility. Frm an ecnmic pint f view, lw biavilability f drug leads t wastage f mre amunt f drug after ral administratin, in case f cstly drug Indian Jurnal f Pharmaceutical Educatin and Research Received n 11/12/2008; Mdified n 15/4/2009 Accepted n 27/9/2009 c APTI All rights reserved increases cst f frmulatin. The apprach slid dispersin has been used t increase water slubility and disslutin rate f prly water sluble drug and t slve biavalability prblems. Ammar et al., reprted that the biavailability and stability f glimepiride can be 7, 8 enhanced in its cmplex frm with â-cycldextrin. Hwever, there is n reprt n the preparatin and evaluatin f glimepiride slid dispersin with plyvinylpyrrlidne K 90. In ur previus study, the ptentiality f imprvement f slubility and disslutin rate f the gliclazide by preparing SDs with PEG 6000, PEG 8000 and 9-11 plyvinylpyrrlidne K 90 was fund. The authrs investigated the physicchemical characteristics and disslutin behavirs f glimepiride in physical mixtures as well as slid dispersins with plyethylene glycl 20, in a previus study. The primary bjective f the present study is t enhance disslutin rate f glimepiride using slid dispersin with plyvinylpyrrlidne K90. The pssible interactins 71

2 between glimepiride and PVP K 90 in bth slid state and liquid states were investigated. Interactin in the slid state was investigated by Furier-transfrm infrared (FT- IR) spectrscpy and X-ray diffractin analysis (XRD). Interactin in slutin was studied by phase slubility analysis and disslutin experiments. MATERIALS AND METHODS Materials A gift sample f glimepiride was received frm Arist Pharmaceuticals Ltd., (Mumbai, India). PVP K 90 was received frm Clariant (Germany). Methds Preparatin f SDs The SDs f glimepiride with PVP K 90 cntaining three different weight ratis (1:1, 1:3, 1:5) (glimepiride: PVP K 90) and dented as SD1/1, SD1/3 and SD 1/5 respectively, were prepared by kneading methd. In kneading methd, a required amunt f PVP K 90 was taken in a glass mrtar alng with 10% lactse. A required amunt f glimepiride was added t mrtar and kneaded thrughly with a glass rd by using ethanl. The mixture was kept fr drying in a desiccatr. The hardened mixture was pwdered in a mrtar, sieved thrugh a 100-mesh screen, and stred in screw-cap vial at rm temperature until further use. Physical mixtures f glimepiride with PVPK 90 cntaining three different weight ratis (1:1, 1:3, 1:5) and dented as PM 1/1, PM 1/3 PM 1/5 were prepared separately. Glimepiride and PVPK 90 were accurately weighed, pulverized and mixed thrughly by light trituratin fr 5 min in a mrtar. The mixture was passed thrugh a sieve n Phase Slubility Studies Slubility determinatins were perfrmed in triplicate 13 accrding t the methd f Higuchi and Cnnrs. The effect f cncentratins f PVPK 90 n the equilibratin slubility f glimepiride in phsphate buffer ph 7.4 at rm temperature was carried ut by adding an excess f drug (50 mg) int a screw-capped glass vial cntaining 10 ml f phsphate buffer ph 7.4 and varius amunts f the carrier (2-10% w/v). The samples were placed n a rtary shaker and agitated at rm temperature fr 48 hr. An aliqut f each slutin was withdrawn and filtered thrugh a 0.45 µm pre size Millipre membrane filter fitted with syringe hlder. The assay f glimepiride was determined spectrphtmetrically at 226 nm, a wave length at which PVPK 90 des nt interfere. The Gibbs free energy f transfer (ÄG tr ) f glimepiride frm pure water t the aqueus slutins f carrier was calculated as Where is the rati f mlar slubility f glimepiride in aqueus slutin f PVP K 90 t that f the same 14 medium withut PVP K 90. Disslutin Studies Disslutin studies f glimepiride in pwder frm, SDs, and PMs were perfrmed by using the U. S. Pharmacpeia (USP) mdel digital tablet disslutin test apparatus-2 (Veeg Scientific C.) at the paddle rtatin speed f 50 rpm in 900 ml f phsphate buffer ph 7.4. The SDs r PMs equivalent t 10 mg f glimepiride was weighed using a digital balance (Ohaus Crp) and added int the disslutin medium. At the specified times (every 10 min fr 1 hr), 10 ml samples were withdrawn by using syringe filter (0.45ìm) (Sepyrane, Mumbai) and then assayed fr glimepiride cntent by measuring the absrbance at 226 nm using the UV-Visible spectrphtmeter (Shimadzu 1601PC, Japan). Fresh medium (10 ml), which was prewarmed at 37 C, was replaced int the disslutin medium after each sampling t maintain its cnstant vlume thrughut the test. Disslutin studies were perfrmed in triplicate (n=3), and calculated mean values f cumulative drug release were used while pltting the release curves. Furier-Transfrm Infrared Spectrscpy Furier-transfrm infrared (FT-IR) spectra were btained by using an FT-IR spectrmeter-430 (Jasc, Japan). The samples (glimepiride r SDs r PMs) were previusly grund and mixed thrughly with ptassium brmide, an infrared transparent matrix, at 1:5 (Sample: KBr) rati, respectively. The KBr discs were prepared by cmpressing the pwders at a pressure f 5 tns fr 5 min in a hydraulic press. Frty scans were btained at a reslutin f 4 cm, frm 4600 t 300 cm. X-Ray Diffractin The X-Ray pwder diffractin patterns were btained at rm temperature using a PW1710 X-ray diffractmeter (Philips, Hlland) with Cu as ande material and graphite 72

3 mnchrmatic, perated at a vltage f 35 kv, current 20 ma. The samples were analyzed in the 2è angle range f 5? 70?and the prcess parameters were set as: scan step size f 0.02? (2è), scan step time f 0.5s. RESULTS AND DISCUSSION Slubility Studies Phase slubility experiments shwed that the cncentratin f glimepiride in buffer ph 7.4 is ntably affected by the presence f PVP K 90. The phaseslubility diagram investigated in buffer ph 7.4 was linear up t cncentratin 8% range f PVP K 90 cncentratins and crrespnd t A -type prfiles (Figure 1). These results are in accrdance with the well established frmatin f sluble cmplexes between water sluble plymeric carriers and prly water sluble 15 drugs. At 8% (w/v) cncentratin f PVPK 90, the slubility f glimepiride increased by 4.04 fld. An indicatin f the prcess f transfer f glimepiride frm pure water t the aqueus slutin f PVPK 90 may be btained frm the values f Gibbs free energy change. The values f Gibbs free energy assciated with the aqueus slubility f glimepiride in presence f PVPK 90. ÄGtr values were all negative fr PVPK 90 at varius cncentratins indicating the spntaneus nature f the drug slubilizatin. The values decreased by increasing PVPK 90 cncentratin, demnstrating that the slubilizatin mre favrable as cncentratin f PVPK 90 increased. Disslutin Studies The results f the disslutin studies fr individual samples (glimepiride alne, PMs and SDs) ver the perid f 1 hur are shwn in Figure 2 and reprted values are the mean f three determinatins (CV<10%). Q, Q and Q values (percent drug disslved in minutes) are reprted in Table 1. Onset f disslutin f pure glimepiride is very lw abut % f drug being disslved in 60 min. SDs f glimepiride with PVPK 90 cnsiderably enhanced disslutin rates within 30 minute cmpared t pure glimepiride and PMs. Percentage disslutin efficiencies (%DE) values were cmputed, fr cmparative analysis all the frmulatins. The % DE values in the initial time perid f disslutin study i.e. %DE 10min prvide cmparative infrmatin fr very fast releasing frmulatins, where as, %DE 30min N prvide relative infrmatin abut bth fast and slw releasing frmulatins. The value f % DE fr the 30min pure drug was increased t % in PM (1:5) and up t 49.29% in SD (1:5). The change f DE f drug in its 30min PMs and SDs is statistically significant (p<0.05). In rder t understand the extent f glimepiride disslutin rate enhancement frm its SDs and PMs, the btained disslutin data f pure glimepiride, SDs, and 16 PMs were fit in Eq. 2. Here, i is disslutin sample number, n is number f disslutin sample times, T mid is time at the mid pint between times Ti and T, and ÄM is the amunt f i-1 glimepiride disslved (µg) between times Ti and T. In i-1 rder t calculate the mean disslutin time (MDT) f pure glimepiride, SDs, and PMs, the mean (n=3) f cumulative drug release (µg) was used. The btained values f MDT fr pure glimepiride, SDs, and PMs are presented in Table 2. The MDT f glimepiride is min, then it decreased t a greater extent 7.17 min after preparing its SDs with PVPK 90 at 1:5 (glimepiride: PVPK 90) rati. The results f the disslutin study indicate an imprvement f disslutin rate f glimepiride in slid dispersin. The rate f disslutin increases as cncentratin f PVPK 90 increases in SDs. The imprvement f disslutin rate is pssibly caused by several factrs. Such factrs are: a) the strng hydrphilic character f PVPK 90, which imprves the water penetratin and the wettability f the hydrphbic glimepiride, b) the ptimal dispersin f glimepiride t PVPK 90, c) the absence f crystals (amrphus dispersins) crrespnds t lwer energy required fr disslutin and d) the inter mlecular hydrgen bnds and the mlecular dispersin f glimepiride n PVP leads t partial miscibility, imprving the hydrphilic characteristics f the drug substance via interactins 17 within the plymer. The imprvement f disslutin rate f glimepiride in PMs is due t increased wettability 18 f the drug pwder. Furier-Transfrm Infrared Spectrscpy The IR spectra f SD and PM were cmpared with the (2) 73

4 standard spectrum f glimepiride (Figure 3). IR spectrum f glimepiride is characterized by the absrptin f carbnyl (C=O) sulphnyl urea grup at 1708 and 1674 cm. Als the NH grup which is lcated at 3369 cm and cm frm the IR spectrum f glimepiride shifted t 3372 cm and 3295 cm in SD. The sulphnyl grup bands are lcated at 1345 cm and 1153 cm in pure glimepiride. In SD, the asymmetrically vibratin peak f S=0 band was shifted frm 1345 cm t 1338 cm with decreased frequencies. In SD, the symmetrically stretching vibratin band f S=0 was shifted frm 1153 cm t 1150 cm with decreased frequencies. The spectrum f PVP K 90 exhibited imprtant bands at 2953 cm (C H stretch) and 1652 cm (C=O). The shift in the peaks assciated with C=O, S=O and NH grup f glimepiride indicates sme srt f slid state interactins between the drug and the plymer in SD and PM. The interactins are due t intermlecular hydrgen bnding between drug and plymer. Intermlecular hydrgen bnd expected t ccur between the hydrgen atm f the NH grup f glimepiride and ne f the lne pairs electrn f C=O grup f plymer r/ and C=O grup f glimepiride and ne f the hydrgen atm f 19 PVPK 90. The FTIR data suggests frmatin f intermlecular hydrgen bnding between glimepiride and PVPK 90. X-Ray Diffractins (XRD) The diffractin spectrum f pure glimepiride shwed that the drug was f crystalline nature as demnstrated by numerus peaks. Numerus diffractin peaks f glimepiride were bserved at 2è f 13.41, 14.62, 16.67, 18.13, , 21.11, and (finger print regin) etc (Figure 4) indicating crystalline glimepiride. Pure PVPK 90 shwed absence f peak. All principal peaks frm glimepiride were present in their respective PM and SD with decreased intensity, which suggested that sme prtin f drug was cnverted int amrphus frm. The X-ray diffractin findings als suggested that sme prtin f drug still existed in the same crystal structures f pure drug and/r frmatin f micrcrystals but the relative reductin f diffractin intensity f drug in SD at these angles suggests that the drug partially 20 cnverted int amrphus frm. CONCLUSIONS The slubility and disslutin rate f glimepiride can be enhanced by the use f SDs f glimepiride with PVPK 90. The slubilizatin effect f PVPK 90, reductin f particle aggregatin f the drug, absence f crystallinity, increased wettability and dispersibility, and alteratin f the surface prperties f the drug particles might be respnsible fr the enhanced slubility and disslutin rate f glimepiride frm its SDs and PMs. ACKNOWLEDGMENT The authrs are grateful t Arist Pharmaceuticals Pvt Ltd, Mumbai, India fr gift sample f glimepiride. Mr. Sudarsan Biswal is grateful t the Principal, Ryal Cllege f Pharmacy and Health Sciences, Berhampur, fr prviding the required facilities fr this wrk Table 1. Effect f PVP K-90 cncentratin and Gibbs free energy n slubility glimepiride 74

5 Table 2: In-vitr disslutin prfile f glimepiride, physical mixture f glimepiride and slid dispersin f glimepiride in ph 7.4 buffer Fig. 1: Phase slubility graph f glimepiride in ph 7.4 buffer 75

6 Fig. 2 : In-vitr disslutin prfiles f glimepiride, physical mixtures and slid dispersin f glimepiride with PVP K 90 in ph 7.4 buffers Fig. 3 : FTIR Spectrgrams f pure glimepiride (A), Pure PVP K 90(B), glimepiride -PVP K 90 PM (C), glimepiride -PVP K 90 SD (D). Fig. 4: X-Ray Diffractgrams f pure glimepiride (A), Pure PVP K 90(B), glimepiride -PVP K 90 PM(C), glimepiride -PVP K 90 SD (D). 76

7 REFERENCES 1. Massim MB. Glimepiride in type 2 diabetes mellitus: a review f the wrldwide therapeutic experience. Clin Ther 2003; 25: Kuichi I, Masaki W, Yuhei N, Takahir S, Nbuki T, Masahik T, et al.,. Efficacy f glimepiride in Japanese type 2 diabetic subjects. Diab Res Clin Pract. 2005; 68: Geinsen K. Special pharmaclgy f the new sulfnylurea glimepiride. Drug Res. 1988; 38: Muller G, Wied S, Wetekam E, Crecelius A, Unkelbach A. Stimulatin f glucse utilizatin in 3P3 adipcytes and rat diaphragm in vitr by the sulfnylureas glimepiride and glibenclamide is crrelated with mdulatins f the camp regulatry cascade. Bichem Pharmacl. 1994; 48: Frick A, Mller H, Wirbitzki E. Bipharmaceutical characterizatin f ral immediate release drug prducts. In vitr/in viv cmparisn f phenxymethylpenicillin ptassium, glimepiride and levflxacin. Eur J Pharm Bipharm. 1998; 46: Thummel KE. Preface. Adv Drug Del Rev. 1997; 27: Ammar HO, Salama HA, Ghrab M, Mahmud AA. Frmulatin and bilgical evaluatin f glimepiride cycldextrin plymer systems. Int J Pharm. 2006; 309: Ammar HO, Salama HA, Ghrab M, Mahmud AA. Implicatin f inclusin cmplexatin f glimepiride in cycldextrin plymer systems n its disslutin, stability and therapeutic efficacy. Int J Pharm. 2006; 320: Biswal S, Sah J, Murthy PN, Giradkar PR, Avari JG. Enhancement f disslutin rate f gliclazide using slid dispersins with plyethylene glycl AAPS Pharma SciTech. 2008; 9(2): Biswal S, Sah J, Murthy P N. Characterisatin f gliclazide-peg 8000 slid dispersins. Trpical Jurnal f Pharmaceutical Research. In press Biswal S, Sah J, Murthy PN. Physicchemical prperties f slid dispersins f gliclazide in plyvinylpyrllidne K-90. AAPS Pharm SciTech.2009;10(2): Baliar Singh OP, Biswal S, Sah J, Murthy PN. Physicchemical prperties f glimepiride in slid dispersins with plyethylene glycl 20,000. Int J Pharm Sc and Nantech. 8(5): Higuchi T, Cnnrs K. Phase slubility techniques. Adv Ana Chem and Instrument. 1965; 4: Chengsheng L, Kashappa GHD, Chenguang L. Enhancement f disslutin rate f valdecxib using slid dispersins with plyethylene glycl Drug Dev Ind Pharm. 2005; 31: Mura P, Manderili A, Bramanti G, Ceccarelli L. Prperties f slid dispersins f naprxen in varius plyethylene glycls. Drug Dev Ind Pharm. 1996; 22 (9&10): Barzegar-Jalali M, Maleki N, Garjani A, et al. Enhancement f disslutin rate and antiinflammatry effects f pirxicam using slvent depsitin technique. Drug Devl Ind Pharm. 2002; 28 (6): Karavas E, Ktistis G, Xenakis A, Gergarakis E. Miscibility behavir and frmatin mechanism f stabilized feldipine-plyvinylpyrrlidne amrphus slid dispersins. Drug Dev Ind Pharm. 2005; 31(4): Frd J L. The current status f slid dispersins. Pharm Acta Helv. 1986; 61: Van den MG, Augustijns P, Blatn N, Kinget R. Physic-chemical characterizatin f slid dispersins f temazepam with plyethylene glycl 6000 and PVP K30. Int J Pharm. 1998; 164: Valizadeh H, Nkhdchi A, et al. Physicchemical characterizatin f slid dispersins f indmethacin with PEG 6000, Myrj 52, Lactse, Srbitl, Dextrin, and Eudragit E100. Drug Dev 77

USING THE POLARITY CHARACTERISTICS OF A DRUG S FUNCTIONAL GROUPS TO ESTIMATE SOLUBILITY CHARACTERISTICS

USING THE POLARITY CHARACTERISTICS OF A DRUG S FUNCTIONAL GROUPS TO ESTIMATE SOLUBILITY CHARACTERISTICS Lessn Objectives 1. Understand what is meant by lgp; knw the difference between MlgP and ClgP 2.