Formulation and Evaluation of Controlled Release Ketoprofen

International Journal of Research in Pharmaceutical and Biomedical Sciences

ISSN: 2229-3701

___________________________________________Research Article

Formulation and Evaluation of Controlled Release Ketoprofen Microspheres Fazil Baig1 and Mohammed Gulzar Ahmed2* 1GM

College of Pharmacy, Bangalore, Karnataka, India.

2Department

of Pharmaceutics, SAC College of Pharmacy, BG Nagar, Karnataka, India.

_____________________________________________________________________________________ ABSTRACT Microspheres are well accepted technique to control the drug release from the dosage form to improve bioavailability, reduce absorption difference in patients, reduce the dosing frequency and adverse effects during prolong treatment. The main objective of the present study is to prepare and evaluate ketoprofen microspheres by solvent evaporation method, with water insoluble polymers using as carrier for oral administration in view to achieve oral controlled release of the drug and to protect the gastric mucous membrane from drug irritation. Ketoprofen is potent NSAID having anti-inflammatory, analgesic, antipyretic properties. It is readily absorbed from the gastrointestinal tract and peak plasma concentrations occur about 0.5–2 h after a dose, but it causes a certain irritation in the gastrointestinal mucous membrane and possesses a bitter taste and aftertaste. The half-life in plasma is about 2–3 h. Preformulation studies performed were comply with the standards. Compatibility studies revealed there was no interaction between the drug and polymers. The various evaluation parameters were given the positive results. From the surface morphology studies, it is observed that it is smooth, uniform and they are spherical in shape.In-vitrodissolution studies wereshowed that the release of drug from microspheres was optimum. All the microspheres were stable with respective storage condition. Key Words: Microspheres, Ketoprofen, Controlled release, NSAID. INTRODUCTION Controlled drug delivery systems designed to deliver drug at predetermined rates for predefined periods of time and have been used to overcome the shortcoming of conventional drug formulations1. The term microspheres describes a monolithic spherical structure with the drug or therapeutic agent distributed throughout the matrix either as a molecular dispersion or as a dispersion of particles (in the 1 - 1000µm size ranges) for use as carries of drugs and other therapeutic agents.Microspheres are well accepted technique to control the drug release from the dosage form to improve bioavailability, reduce absorption difference in patients, reduce the dosing frequency and adverse effects during prolong treatment2. Ketoprofen is potent NSAID having anti-inflammatory, analgesic, antipyretic properties, and is used in the treatment of rheumatoid arthritis, osteoarthritis, and ankylosing spondylitis. It is readily absorbed from the gastrointestinal tract and peak plasma concentrations occur about 0.5–2 h after a dose, but it causes a certain irritation in the gastrointestinal mucous membrane and

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possesses a bitter taste and aftertaste3. The half-life in plasma is about 2–3 h. The short half-life and the low single administration dose make ketoprofen a very good candidate for the formulation of controlled release dosage forms.The main objective of the present study was to prepare and evaluate ketoprofen microspheres by solvent evaporation method, with water insoluble polymers,such as an eudragit RS and eudragit RLusing as carrier for oral administration in view to achieve oral controlled release of the drug and to protect the gastric mucous membrane from drug irritation or to mask its unpleasant taste. EXPERIMENTAL METHODS Compatibility of the drug (Ketoprofen) with excipient Eudragit RS and Eudragit RL, which were used to produce microspheres, was established by FT IR absorption spectral analysis and observation was made weather changes in chemical constitution of drug after combining it with the excipient occurred4. Preformulation study is one of the important prerequisite in development of any drug delivery system. It gives the information needed to define the

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nature of the drug substance and provide a framework for the drug combination with pharmaceutical excipients in the dosage form.Hence, preformulation studies on the obtained sample of drug for identification including colour tests, solubility analysis, melting point determination and compatibility studies were performed.Preformulation solubility analysis was done, which include the selection of suitable solvent, to dissolve the respective drug as well as various excipients used for the fabrication of microspheres.Melting point determination of the obtained sample was done because it is a good first indication of purity of the sample, since the presence of relatively small amount of impurity can be detected by a lowering as well as widening in the melting point range5. Preparation of microspheres of Ketoprofen Ketoprofen microspheres were prepared by Solvent evaporation methodusing different quantities of Eudragit RS and Eudragit RL polymers (Table 1). Approximately 1.0, 2.0, 3.0 g or mixture of both were accurately weighted and dissolved in 27 mL of acetone with mechanical stirrer (RemiMixer, Mumbai). A 1g quantity of the powdered ketoprofen and 100 mg of magnesium stearate were then dispersed in the polymer solution. The resultant

ISSN: 2229-3701

milky white dispersion was poured into a vessel containing a mixture of 270 mL liquid paraffin and 30ml of n-hexane and stirred for 3 hours at 1000 rpm or until the acetone was completely evaporated. Following removal of the acetone, the resultant microspheres were collected by vacuum filtration after which they were washed four times with 25 mL of n-hexane and dried at room temperature (25 0C) for 24 hrs6.The formulation procedure is schematically represented in figure 1. Evaluation of Microspheres The various evaluation parameters like, Percent yield, Sieve analysis, Micromeritic properties and flow properties like Angle of repose,Bulk density and Tapped density, Carr’s indexwas performed.Study of shape, surface morphology and Drug entrapment efficiency was also performed7. Percent yield value of Microspheres The percent yield values of each batch of microsphere were obtained on weight of dried microspheres with respect to the total solid material amount in the dispersed phase7. The yield of microspheres preparation was calculated using the formula:

The amount of microspheres obtained (g) Percent yield =

× 100 The theoretical amount (g)

Sieve analysis Separation of the microspheres into various size fractions was carried out using a mechanical sieve shaker. A series of ten standard stainless steel sieves were arranged in the order of decreasing aperture size. 10 g of drug-loaded microspheres was placed on the upper most sieve, then sieves were shaken for a period of about 10 min. and then the particles on the screen were weighed7. The procedure was carried out three times for each product and the size fraction was calculated as follows. Σnd Average Size = ——— Σn Where, n is the number of microspheres and d is the size of microsphere. Micromeritic properties Flow properties of microspheres were studied by measuring the angle of repose of the formulation by employing fixed funnel standing method as per the reported procedure.Bulk and tapped densities were measured by using standard bulk density apparatus7. Similarly compressibility index (Ci) or Carr’s index

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value of microspheres was computed according to the following equation: (Tapped density – Bulk density) Carr’s index =

x 100 Tapped density

Study of shape and surface morphology SEM is probably the most commonly used method for characterizing drug delivery systems, owing in large part to simplicity of sample preparation and ease of operation. It is used to determine shape, particle size distribution, surface topography, texture and to examine the morphology of fractured or sectioned surface. The microspheres were coated uniformly with gold by using ion sputter coater, after fixing the sample in individual brass stabs. All samples were randomly examined for surface morphology of microspheres by using Scanning electron microscope8. Drug entrapments efficiency ketoprofen-loaded microspheres (100mg) were dispersed in 50 ml of 96% ethanol in a 100 ml


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volumetric flask and sonicated for 2 hrs on a sonicator (PCI Services, Mumbai, India) for complete extraction of drug, then the resulting solution was filtered through whattmanfilter paper no. 1. The 5 ml filtrate diluted appropriately with phosphate buffer

ISSN: 2229-3701

pH 7.4 and concentration of Ketoprofen was determined spectrophotometrically at 260 nm using UV-Vis Spectrophotometer (Shimadzu -1700)9. Encapsulation efficiency were calculated in duplicate for all batches using the equation as follows

Practical Drug content Drug Entrapments Efficiency =

× 100 Theoretical Drug Content

In-vitro Dissolution Study In-vitro release profile of Ketoprofen microspheres studies were performed, using USP Type II dissolution test apparatus. Microspheres weighted equivalent to 100mg of Ketoprofen wrapped in parchment paper and placed in the dissolution vessel containing 900mL of dissolution medium. The medium was maintained 37 ±0.5 0C and stirred at 100 rpm. Thein-vitro dissolution studies were performed at three different pH values (i) 1.2 pH, (artificial gastric juice); (ii) pH 6.0 phosphate buffer (artificial small intestinal fluid) and (iii) pH 7.4 phosphate buffer (artificial colonic fluid). The sample (5 mL) was withdrawn at each hour interval, withdrawn solution filtered through a 0.45µm membrane filter and replaced with the same volume of test medium and withdrawn sample were diluted if required and then estimated for Ketoprofen at 260 nm spectrophotometrically using Shimadu 1700 UVVisible spectrophotometer. Corresponding concentrations in sample were calculated from standard plot and calculated cumulative percentage of drug release from each formulations.The data obtained was subjected to kinetic treatment to obtain the order of release and release mechanism10. StabilityStudies It is necessary to perform stability testing to find out the extent of deterioration and to ensure the degradation has not exceeded an acceptable level assuring the safety of the patient and the activity of the product.If pharmaceutical preparations or new formulations are stored under normal conditions, their instabilities are detectable only after long storage periods. Such a method is time consuming and uneconomical. In an attempt to reduce the time required to obtain information about instabilities, various stress tests are undertaken. The most common stress conditions used are temperature, humidity and light. Optimized formulation of the microparticles was selected for stability studies Formulations were packed in a screw capped bottle and studies were carried out for 90 days by keeping at various storage conditions. In present study, the formulation F2 was

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selected for the study and formulation were packed in amber colored bottles tightly plugged with cotton and capped. They were then stored at 25oC/ 60% RH & 30oC/ 65% RH & 40oC/ 75% RH for 3 months and evaluated for their drug content11. RESULTS AND DISCUSSION In the present study, it was aimed to develop ketoprofenmicrospheres using water insoluble polymer as a carrier for oral administration to extend the period of the dosage form. The compatibility studies by FT IR spectrum of pure drug and with polymer mixture revealed that there was no interaction between polymer and drug. Thepercentage yield was very high(86.38% -91.38%) for all microspheres. The average particle size is ranges from135-665µm, the particle size distribution was shown in figure 2. The micomeretic properties like bulk and tapped densities showed good packability and Carr’s index results shown excellent compressibility. The surface morphology carried out by using SEM studies showed that the prepared microspheres were having smooth surface and spherical in shape, the photo micrographs by SEM of three formulations were shown in figure 3. The entrapment efficiency was good for all the preparation, but was highest for F-9 formulation. In-vitro release studies of Eudragit RL microspheres showed faster release pattern for all (F4 to F6) formulations with initial burst effect, which may be has a greater proportion of quaternary ammonium groups in their structure. As drug release rates were very slow and incomplete from Eudragit RS microspheres. Eudragit RS microspheres showed at initially very less release of drug from microspheres, compared to Eudragit RL microspheres. Overall, the curve fitting into various mathematical models was found to be average and the in-vitro release of formulation best fitted into the Zero-order. The comparative release profile was shown in figure-4 The stability studies of formulations F-9 indicate that 25 oC is a suitable temperature for storage of Eudragit RS / RL microspheres of Ketoprofen.


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ISSN: 2229-3701

Table 1: Formulation formula for Ketoprofen containing Eudragit microspheres Formulation. code F1 F2 F3 F4 F5 F6 F7 F8 F9

Ketoprofen (g) 1 1 1 1 1 1 1 1 1

Eudragit RS (g) 1 2 3 1 0.5 0.75

Eudragit RL(g) _ 1 2 3 0.5 1 0.75

Fig. 1: Schematic representation of formulation of Ketoprofen microspheres

35

% Retained on the sieve

30 25 20

F7 F8

15

F9

10 5 0 135

165

215

287.5

375

462.5

550

655

Partica l Size

Fig. 2: Particle Size Distribution of three of Ketoprofen Loaded Microspheres (F7 to F9)

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F7

ISSN: 2229-3701

F8

F9

Fig. 3: SEM Photograph of Ketoprofen –loaded Microspheres

Fig. 4: Comparative in vitro release profile of ketoprofen microspheres

CONCLUSION Over the years, attempts have been made to control the time course and specificity of drug in the body through a variety of drug modifications and dosage forms. The need of making any drug microspheres is to produce a drug delivery system which is safe and capable of producing consistent blood levels of drug in the body for required period of time. It also improves keeping and handling properties of the drug. Among the microparticulate system, microspheres have a possible to target drug and provide controlled release. In the present study, it was aimed to prepare microspheres of Ketoprofen using a biodegradable and non-biodegradable polymer as a carrier for oral administration to extend the period of the dosage form.The IR spectrum of pure drug and drug –

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polymer mixture revealed that there was no interaction between polymer and drug. The prepared microspheres were spherical shape with smooth surface and the yields of preparation were very high for all microspheres obtained. Bulk and tapped densities showed good packability and Carr’s index results shown excellent compressibility. The entrapment efficiency was good for all the preparation, but was highest for F-9 formulation. As polymer concentration increases, the particle size increases. Particle sizes of combined polymer microspheres were greater than individual polymer. In-vitro release studies of Eudragit RL microspheres showed faster release pattern for all formulations with initial burst effect. Whereas drug release rates were very slow and incomplete from Eudragit RS microspheres. Overall, the curve fitting into various mathematical models was found to be average and


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the in-vitro release of formulation best fitted into the Zero-order. From the stability studies it was observed that the 25oC is a suitable temperature for storage of Eudragit RS / RL microspheres of Ketoprofen. Further detailed investigations are required to establish efficacy of these formulations like the invivo study, the in-vitro / in-vivo correlation, preclinical and clinical study is necessary for the use of Ketoprofen microspheres as oral controlled drug delivery and bioavailability study in human volunteers is necessary to establish drug product. REFERENCES 1. Chiao Charles SL and Robinson JR. Sustained release drug delivery system. Remington’s Pharmaceutical sciences, 19th ed. Mac Publishing Company 1999; 1660. 2. Sandile M. Khamanga, Natalie Parfitt et. al., The evaluation of Eudragit microcapsules manufactured by Solvent evaporation using USP Apparatus 1. Dissolution Technologies May 2009; 02: 15-22. 3. Tripathi KD. Non- steroidal anti-inflammatory drugs and anti-pyretic analgesics. Essential Medical Pharmacology. 5th ed. Jaypee Publications (P) Ltd., New Delhli 2003; 167-84. 4. Ravi S, Peh KK, Yusridadarwis, Krishna Murthy B, Raghu Raj Singh T and Mallikarjun C. Development and Characterization of polymeric microspheres for controlled release

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protein loaded drug delivery system. Indian Journal of Pharmaceutical Sceince; May 2008, 70(3): 303-09. 5. Arul B, Kothai R, Sangameshwaran B and Jayakar B. Formulation and evaluation of chitosan microspheres containing Isoniazide. Ind J Pharm Sci., Nov 2003; (65): 640-42. 6. MallickS et. al., Development and characterization of release profile of Nifedepine as effective controlled release system. Journal of scientific and Ind.res. 1999 ;(58): 1010-16. 7. Carstensen J T. Preformulation. In Banker GS, Rhodes CT. Modern Pharmaceutics. 3rded. New York: Marcel Dekker; 1996; 213-37. 8. Eun-Jin Lee, Sa-Won Lee, Han-Gon Choi, Chong-Kook Kim. Bioavailability of cyclosporine A dispersed in sodium lauryl sulfate-dextrin based solid microspheres. Int. J Pharm 2001 ;( 218) 125-31. 9. Sachin S. Pandit, Dinesh P. Haseet. al., Ketoprofen-loaded Eudragit RSPO microspheres: An influence of sodium carbonate on invitro release and surface topology. Journal of Microencapsulation. 2009; 26(3): 195-01. 10. Patil SS and Kasture PV. Studies on preparation and evaluation of biodegradable poly (lactide-coglycolide) microspheres of aceclofenac. CMU. J. Nat. Sci. 2007; 6(2): 195-05. 11. CVS Subrahmanyam. Textbook of Physical Pharmaceutics, Micromeritics 2nd ed., VallabhPrakashan 2002; 222-24.


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