FORMULATION AND EVALUATION OF ION EXCHANGE RESIN BASED TASTEMASKED SUSPENSION OF LEVOFLOXACIN HEMIHYDRATE: A FLOUROQUINOLONE ANTIBIOTIC

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1 Page493 Indo American Journal of Pharmaceutical Research, 2015 ISSN NO: FORMULATION AND EVALUATION OF ION EXCHANGE RESIN BASED TASTEMASKED SUSPENSION OF LEVOFLOXACIN HEMIHYDRATE: A FLOUROQUINOLONE ANTIBIOTIC Ajay Bilandi 1 * and Amiya Kanta Mishra 2 1 Research Scholar, Bhagwant University, Ajmer, Rajasthan, India. 2 Principal, College of Pharmaceutical Sciences, Puri, Orissa, India. ARTICLE INFO Article history Received 09/01/2015 Available online 30/01/2015 Keywords IER, DRC, Taste Masking, Similiarity Factor, Tulsion-335. ABSTRACT Taste is an important factor in the development of dosage form. Certain drugs that have very bitter taste can be made relatively tasteless by adsorbing the drug on ion exchange resin although all the ion exchange resins can be useful for this purpose, the proper selection on ionic character of drug and release characteristics. The main objective of the present invention is to provide an oral composition which can deliver a pharmacokinetically acceptable dosage of a beneficial agent, or to at least provide the patient with a useful choice and to provide a taste masked composition. Levofloxacin hemihydrate is very bitter in taste and mostly used for pediatric suspensions to treat the infections.tulsion-335, ion exchange resin, was used to mask the bitter taste of drug. In this research work firstly prepare the drug resin complexes in different ratios by batch method and evaluated for various parameters including tastemasking. After successful preparation of DRC, the complexes were used to formulate taste masked suspension. Taste masked suspension was also evaluated for taste masking and in-vitro release study. Formulated suspension was compared with marketed levofloxacin syrup and calculated the similiarity factor. Accerlated stability study was also performed for one month. Based on the evaluation data obtained after one month stability study, it was concluded that the formulated suspension with SDRC was successfully taste masked, stable and reproducible in nature. Corresponding author Ajay Bilandi 45- Tilak Nagar Sri Ganganagar Rajasthan. ajay_bilandi2001@yahoo.com Please cite this article in press as Ajay Bilandi et al. Formulation And Evaluation of Ion Exchange Resin Based Tastemasked Suspension of Levofloxacin Hemihydrate: A Flouroquinolone Antibiotic. Indo American Journal of Pharm Research.2015:5(01). Copy right 2015 This is an Open Access article distributed under the terms of the Indo American journal of Pharmaceutical Research, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

2 Page494 INTRODUCTION The problem of bitter and obnoxious taste of drug in pediatric and geriatric formulations is a challenge to the pharmacist in the present scenario. In order to ensure patient compliance bitterness masking becomes essential. [1] Most of the fluoroquinolones suspensions taste very bitter, which will limit the oral routes of administration. Therefore, it is essential to develop a suitable taste masking oral fluoroquinolones suspension. Taste masking technologies rely on the prevention of interaction between the drug molecule and the oral mucosal surface. By creating a physical barrier around each particle, the drug substance can be prevented from going into the solution and interacting directly with taste receptors. Levofloxacin has a bitter taste and is particularly useful in treatment of common pediatric infections of the middle ear and upper respiratory tract, as well as certain forms of pneumonia which afflict the elderly. Taste masking with IER technique is the simplest and least expensive for bitter drugs and to formulate by considering an ambient temperature and stability of antibiotics. [2,3] Present invention provides a taste masked levofloxacin suspension-dosage form by ion exchange resins that deliver an equivalent dose, the incidence and/or severity of GI side effects. Tulsion 335 is a weakly acidic Nicotine Polacrilex preparation. It is suitable for pharmaceutical applications such as cynocobalamin loading / stabilization of vitamin B12 and taste masking of Norfloxacin, Roxithromycin, and Ofloxacin etc. [5] Ion-exchange reaction, any of a class of chemical reactions between two substances (each consisting of positively and negatively charged species called ions) that involves an exchange of one or more ionic components. [4] The main objective of this research work mask the bitter taste of levofloxacin hemihydrates using tulsion-335, an ion exchange resin and formulation of a taste masked, stable and reproducible suspension dosage form. MATERIAL AND METHODS Material Levofloxacin Hemihydrate was gift sample from Morepen Laboratories ltd, Solan, Badi. H.P., India. Tulsion 335 was obtained as gift sample from Ion exchange India limited (Mumbai, India). Methodology Formulation of Drug Resin Complex (DRC) The resin was purified with methanol, benzene and distilled water and activated by using 0.1 M HCl. Drug resin complex were formulated by batch method. [6,7] Levofloxacin and all the resin were weighed in specified amount as per different ratio i.e. 1:1, 1:2, 1:3 and 1:4 shown in Table1. Tulsion 335, kyron T114 and Tulsion 344 were suspended separately in specified amount of 0.01m/L HCl solution containing 250 mg of levofloxacin hemihydrates with magnetic stirring at 30 0 C for 3 h. The levofloxacin hemihdrate resinates were then washed off the physical absorbed levofloxacin on the resinates with deionized water and were dried at 40 C. [8, 9, and 10]. Table 1: Composition of DRC of levofloxacin hemihydrates with Various IER Formulation Batch Drug - Resin Ratio Levofloxacin Hemihydrate Tulsion 335 (mg) (mg) DRC 1 1: DRC 2 1: DRC 3 1: DRC 4 1: Evaluation Tests for DRC Yield of DRC Thoroughly dried drug resin complex were collected and weighed accurately. The percentage yield was then calculated (Table 3) using formulae given below, Percentage Yield = 100 Determination of Percentage Drug loading (PDL) in dug resin complex (DRC): The loading amount of levofloxacin hemihydrate in the drug resinates was determined by suspending 150 mg levofloxacinresinates in 100 ml HCl solution (0.25 mol/l) magnetically stirred for 6 h at 60 C. The solution was then filtered, and the amount of levofloxacin in the filtrate was determined using ultraviolet (UV) spectroscopy at 326 nm (Table 4). [10] Efficiency of drug entrapment for each batch was calculated in terms of percentage drug entrapment as per the following formula: PDL = Practical drug loading Theortical drug loading X 100

3 Page495 Theoretical drug loading was determined by calculation assuming that the entire Levofloxacin hemihydrate present in the 0.01 mol/l HCl solution used gets entrapped in resin, and no loss occurs at any stage of preparation of Levofloxacin hemihydrates resin complex. [11, 12] Assessment of the bitter taste of levofloxacin (Bitterness threshold): The threshold bitter concentration is the lowest concentration at which a material continues to provoke a bitter sensation after 30 seconds. The bitter taste threshold value of levofloxacin was determined based on the bitter taste recognized by six volunteers (3 females and 3 males). A series of levofloxacin aqueous solutions were prepared at different concentrations as standard solutions, that is, 10, 20, 30, 40 and 50 μg/ml, respectively. The test was performed as follows: 1 ml of each standard solution was placed on the center of the tongue, it was retained in the mouth for 30 s, and then the mouth was thoroughly rinsed with distilled water [13, 14]. Interval of at least 10 seconds observed between two tests subsequently. The threshold value minutes was correspondingly selected from the different levofloxacin concentrations as the lowest concentration that had provoked a bitter taste (Table 5). Taste Evaluation: Taste evaluation of drug resinates was performed by 6 volunteers in the age group of 18 to 24 years. The study protocol was explained and written consent was obtained from the volunteers. 100 mg of levofloxacin powder and the drug resinates equivalent to 100 mg levofloxacin were separately held in the mouth for 30 seconds by each volunteer. Bitterness levels were recorded both instantly and after 30 seconds. The bitterness level was recorded against pure drug by using a numerical scale (Table 6). The numerical scale was used with the following values: 0 =sweet, 1 = tasteless, 2 = acceptable bitterness, 3 = slight bitterness, 4 = moderately bitterness and 5 =strong bitterness [15, 16, and 17]. Formulation and Evaluation of Levofloxacin hemihydrates Tulsion 335 complex Suspension: Formulation of Suspension: Suspension were prepared by using levofloxacin hemihydreate alone (S1) and with 1:2 ration of levofloxacin Tulsion 335 resin complexes (S 2 to S 5 ) shown in table no.2. Preparation of drug resin complex: Weighed quantity of Tulsion 335 resin was added in clean beaker containing specified quantities of 0.01 m/l HCl with stirring for 15 min. Weighed quantity of levofloxacin hemihydrate was added in resin solution and stirred for 4 hrs continuously. Liquid obtained after stirring was filtered and dry at 40 C. Dried DRC was passed through sieve no. 22 and used for further preparation of suspension. [8, 9 and 10] Preparation of syrup base: A weighed quantity of sugar was dissolved in specified quantity of boiled water and filtered. Weighed quantities of Sorbitol, Glycerine, Xanthan gum, guar gum Tween-80, Saccharin, Methyl paraben, Propyl paraben, were added in sugar solution under stirring. Mixing of DR complex with Syrup: The drug resin complex obtained was added in to sugar solution under stirring. Weighed quantities of coloring & flavoring agents were added in above solution & stirred for 30 min. The volume of suspension was made up to required quantity by using purified water. [1]. Formulation of Suspension (S 1 ) with drug alone: weighed quantity of drug was taken and added to syrup base with continued stirring for 30 minutes at 40 C. Table 2: Formula table for Taste Masked suspensions with Tulsion-335. S.No Material S 1 S 2 S 3 S 4 S 5 1 DRC (1:2) Levofloxacin Hemihydrate Equivalent to 200 mg of levofloxacin Equivalent to 200 mg of levofloxacin Equivalent to 200 mg of levofloxacin Equivalent to 200 mg of levofloxacin Syrup preparation 2 Sucrose (mg) Glycerin (ml) Xanthan Gum (mg) Propyl paraben(mg) Methyl-phydroxybenzoate (mg) 7 Saccharin(mg) Strawberry flavor (ml) Purified water (ml)

4 Page496 Evaluation of Suspension Appearance All the five suspensions were tested for uniformity of dispersion and colour (Table 8). Taste Evaluation All the five formulated suspensions were examined for the taste and palatability. Bitter taste was evaluated based on human bitter taste recognized by volunteers. The study protocol was explained and written consent was obtained from volunteers. Suspension equivalent to 200 mg of Levofloxacin hemihydrate was held in the mouth for 15seconds by each volunteer, the bitterness level was compared with formulation S 1 (Table 9 &10). [18] ph ph of all the suspensions were determined by ph meter (Table 11). Viscosity Viscosity is a critical parameter of suspension and was determined the help of a Brookfield synchrolectic viscometer. In a 25 ml glass beaker 15ml of suspension has taken and the viscometer is set over the beaker by a stand. Switch on the viscometer and run it till its torque value set between 60 to 80. Spindle no.1 was used to measure the viscosity of suspension. All determinations were done in triplicate and the results are expressed as the mean values (Table 12). [18] Sedimentation volume (F) The formulated suspensions were evaluated for physical stability by determining the sedimentation Volume. Fifty ml each of suspension was taken in 50 ml stopped graduated measuring cylinder. The suspension was dispersed thoroughly by moving upside down for three times. Later, the suspension was allowed to settle for three minutes and the volume of sediment was noted. This is the original volume of sediment (Ho). The cylinder was kept undisturbed for 14 days. The volume of sediment read at 1 hr and on the 14th day was considered as final volume of sediment (Hu). The redispesibility of the suspensions was checked by moving the stoppered cylinder upside down until there was no sediment at the bottom of the cylinder (Table 13). [19, 20] Sedimentation volume of the formulations was determined using following formula. F = Hu / H0 Whereas, F = Sedimentation volume. Hu = Ultimate settled height of suspension. H0 = Original height of the suspension before settling. The sedimentation volume can have values ranging from less than 1. The ultimate height of the solid phase after settling depends on the concentration of solid and the Particle size. To obtain an acceptable suspension, F should be at least 0.9 for 1 h but a longer period was preferred for prepared formulations. [18] Particle size The size was measured using an optical microscope (Magnus MLX DX) and the mean particle size was calculated. The slide containing suspension particles was mounted on the stage of the microscope and diameter of at least 100 particles was measured using a calibrated optical micrometer. Photomicrographs (10 x magnifications) of resin and suspension were taken. Eye piece micrometer was calibrated using stage micrometer, where X number of eyepiece visions y- number of stage micrometer divisions. 2. Eye piece division= (Y least count/x) 3. Sample was uniformly suspended in paraffin oil. 4. A slide of above suspension was prepared, placed under microscope and the size of the particles was measured. (Table 14 and figure 4). [21, 22] Redispersibility Resuspendability of suspension was expressed in terms of number of shakes (produced by hard shaking) required to redisperse. The prepared suspension formulations S 1 to S 5 were taken in 50 ml measuring cylinder and shaked until complete redispersion of each suspension and note down the number of shakes required for redispersion with nature of settled layer of each suspension. Samples were taken in triplicate (Table 15). [1] Drug content 10 ml of suspension was taken in 100 ml volumetric flask & volume was made up to 100 ml with acidic buffer ph 1.2. Sonicate it for 15 min. Take 2 ml solution in to 200 ml volumetric flask, volume was made up to 200 ml with acidic buffer ph 1.2 & filtered. Absorbance was measured at wavelength 326 nm in U.V. Spectrophotometer & compared with standard and then % drug content. Same process repeated with salivay ph buffer 6.8. Samples were taken in triplicate (Table 16 & 17). [1]

5 Page497 Assay of Oral taste masked suspension 10 ml of suspension was taken in 100 ml volumetric flask & volume was made up to 100 ml with 0.1 N HCL. Sonicate it for 15 min. Taken 2 ml solution in to 200 ml volumetric flask, volume was made up to 200 ml with 0.1 N HCL & filtered. Samples were taken in triplicate. Absorbance was measured at wavelength 326 nm in U.V. Spectrophotometer & compared with standard and then % drug content (Table 18). [1] In-vitro dissolution In vitro drug release of the different suspensions (S 1 -S 5 ) was carried out using USP type II dissolution apparatus (paddle type). The dissolution medium, 900ml 0.1N HCL, was placed into the dissolution flask maintaining the temperature of o C and rpm of ml suspension was placed in each vessel of dissolution apparatus. The apparatus was allowed to run for 60 minutes. Samples measuring 5 ml were withdrawn after every 5, 10, 15, 20, 30, 45, & 60 min. using 5 ml syringe. The fresh dissolution medium was replaced every time with the same quantity of the sample. Collected samples were suitably diluted with 0.1N HCL and analyzed at 326 nm using 0.1 N HCL as blank. The cumulative percentage drug release was calculated (Tables 19 and Figure 5). [23] In-vitro dissolution of marketed oral solution of levofloxacin The in vitro release of marketed levofloxacin oral solution (L- CIN Syrup, Lupin Ltd., Batch no. A ) was determined by USP type II dissolution apparatus (paddle type). [23] The dissolution medium, 900ml 0.1N HCL, was placed into the dissolution flask maintaining the temperature of o C and rpm of ml oral solution was placed in each bucket of dissolution apparatus. The apparatus was allowed to run for 60 minutes. Samples measuring 5 ml were withdrawn after every 5, 10, 15, 20, 30, 45, & 60 min. using 5 ml syringe. The fresh dissolution medium was replaced every time with the same quantity of the sample. Collected samples were suitably diluted with 0.1N HCL and analyzed at 326 nm using 0.1 N HCL as blank. The cumulative percentage drug release was calculated (Table 20 and Figure 6). RESULT & DISCUSSION Formulation of Drug Resin Complex (DRC): Drug Resin Complex were formulated by batch method in various ratio from 1:1 to 1:4 of levofloxacin and Kyron T-114, Tulsion 335 and Tulsion 344. Evalution Tests for DRC Yield of DRC: Percentage yield of different formulation of DRC was determined by weighing the DRC after drying. The percentage yield of different formulation was in range of % as shown in Table 3. The maximum percentage yield was found in DRC 2. Formulation Batch Table 3: Percentage yield of the prepared DRC Initial Weight of Ingredients (mg) Theoretical Yield (mg) Yield of Formulation (mg) % Yield DRC DRC DRC DRC Determination of Drug loading in dug resin complex (DRC): Drug loading in various ratio of DRC were determined by method mentioned earlier and results are shown below in table no. 4. The percentage Drug loading in all drug resin complexes was found in the range of to It s shown that the drug loading was excellent in all DRC 1 to DRC 4. Table 4: Drug loading on DRC Formulation Batch % Drug loading DRC DRC DRC DRC Assessment of the bitter taste of levofloxacin hemihydrate (Bitterness threshold): The bitter taste threshold of levofloxacin hemihydrates was determined among six volunteers and the results shown in table no. 5.

6 Page498 Table 5: The Bitterness threshold of levofloxacin hemihydrates No. of candidate Concentration of drug (μg/ml) Most of the volunteers reported the threshold bitterness at 40 μg / ml. Taste Evaluation Taste evaluation of Drug-Resin Complex in volunteers confirmed that the taste of Levofloxacin was successfully masked by complexing it with Tulsion 335 with 1:1 to1:4 ratio of drug to resin. All the volunteers had shown that DRC was tasteless and agreeable. Also the DRC was stable in salivary ph for a period of administration. The efficiency of resin could be checked by bitterness level of DRC. The bitterness level was divided into six different categories like extremely strong bitter, moderately bitter, slightly bitter, acceptable bitter, no bitter and sweet. The numerical scale was used with the following values: 0 = sweet, 1 = tasteless, 2 = acceptable bitterness, 3 = slight bitterness and 4 = moderately bitterness and 5 =strong bitterness. All the DRC formulation also treated with ANOVA and shown in table 6 that the DRC 1 - DRC 4 prepared with Tulsion 335 resins have a significant difference in taste. The p value is < Table 6: Taste Evaluation of Drug powder and various Formulated DRC Preparations with Tulsion 335. Volunteer Drug powder DRC 1 DRC 2 DRC 3 DRC 4 Instant 30 s Instant 30 s Instant 30 s Instant 30 s Instant Sum ANOVA P< Particle size & Swelling study of resins and DRC As described in table 7, the particle size of Tulsion 335 in normal and swollen condition was measured microscopically. The mean particle size of Tulsion 335 particles was 32 ± 3.6, which is in confirmation with the reported size (<75 μm), which presents an enormous surface area of ion exchange resin that is useful for taste masking. Substantially small size particles are difficult to process and particles greater than 200 μm have a tendency to fracture. Tulsion 335 is highly porous, and even though insoluble in water, it is capable of hydration [4]. A higher degree of swelling is suggestion of the fact that on hydration, the resin is producing a swollen porous network structure that is capable of allowing the drug molecules to permeate /diffuse inside and also get complexed with the resin. The mean particle size of swollen Tulsion 335 was 44 ± 4.7. Figure 1 & 2 shows the photomicrograph of non swollen and swollen Tulsion335 particles in distilled water and non swollen and swollen DRC in distilled water. Table 7: Particle size of non-swollen & swollen resin and DRC Material Particle Size (μm) Non swollen Tulsion ± 3.6 Swollen Tulsion ± 4.7 Non swollen DRC 42 ± 3.9 Swollen DRC 54 ± s

7 Page499 Non-swollen Tulsion 335 Swollen Tulsion 335 Figure 1: Photomicrographs of swollen and non-swollen resin Non-swollen DRC Swollen DRC Figure 2: Photomicrographs of swollen and non-swollen DRC Morphology of DRC Scanning electron microscopy shown that the particles of Drug resin complexes were smooth, irregular in shape with average particle size 64.5 μm, which is in confirmation with the reported size (<75 μm), which presents an enormous surface area of ion exchange resin that is useful for taste masking. The SEM pictures show particles on the surface of resins reveals that the drug has been adsorbed on the surface of resins.

8 Page500 Figure 3: SEM of Levofloxacin Tulsion 335 Complex (SDRC Ratio 1:2). Selection of DRC for final formulation of taste masked suspension All the DRC preparations of different ratio were tested for percentage yield, drug loading and taste masking efficiency. DRC 1 to DRC 4 (levofloxacin hemihydreate and Tulsion 335 complexes) was shown the taste masking effect. Ratio 1:4 and 1:3 was shown the almost same taste masked effect but Ratio 1:2 was shown more taste masking than 1:1 ratio of drug resin and slightly less than 1:3 and 1:4 ratio. The minimum dose of levofloxacin hemihydrate is required for acute infection is 250 mg. The high amount of DRC (equivalent to 250 mg drug) required for dose compilation. So due to high requirement of DRC and very low difference in taste masking effect, DRC of 1:2 ratio was selected for final formulation of taste masked suspension dosage form. The percentage yield and drug loading was also better in DRC 2. Formulation and Evaluation of Levofloxacin hemihydrates Tulsion 335 complex Suspension: Formulation of Suspension: The suspension of selected drug resin complex was formulated in triplicate and evaluated for various parameters. The final formulation of suspension was compared with marketed formulation of levofloxacin. Evaluation of Suspension: Appearance The appearance of all the three formulations with drug (S I ) and taste masked suspension (S 2 S 5 ) was checked visually in the form of uniformity and colour. All the suspensions were shown the uniform dispersion and lemon yellow colour as in table no. 8. Table 8: Appearance of different Suspension formulations Suspension Uniformity of Dispersion Colour of suspension Formulation S 1 Uniform Lemon yellow S 2 Uniform Lemon yellow S 3 Uniform Lemon yellow S 4 Uniform Lemon yellow S 5 Uniform Lemon yellow Taste Evaluation of suspension Taste evaluation of drug powder, suspension prepared with drug only (S 1 ) and suspension prepared with selectd Drug-Resin Complex (S 2 S 5 ) in volunteers confirmed that the taste of Levofloxacin was successfully masked by complexing it with Tulsion 335 with 1:2 ratio of drug to resin. All the volunteers had shown that the all suspension with SDRC (S 2 - S 5 ) were tasteless and agreeable. The efficiency of resin could be checked by bitterness level of suspension. The bitterness level was divided into six different categories like extremely strong bitter, moderately bitter, slightly bitter, acceptable bitter, no bitter and sweet. The numerical scale was used with the following values: 0 = sweet, 1 = tasteless, 2 = acceptable bitterness, 3 = slight bitterness and 4 = moderately bitterness and 5 =strong bitterness. All the Suspension formulation also treated with ANOVA and shown that the S 2 - S 5 prepared with Tulsion 335 resins have a significant difference in taste with the suspension of drug powder alone S 1. p value was found less than shown below in table no.9 & 10.

9 Page501 Table 9: Taste Evaluation of different Suspension formulations by panel method Volunteer Drug powder S 1 S 2 S 3 Instant 30 s Instant 30 s Instant 30 s Instant 30 s Sum ANOVA P< Table 10: Taste Evaluation of different Suspension formulations by panel method Volunteer Drug powder S 1 S 4 S 5 Instant 30 s Instant 30 s Instant 30 s Instant 30 s Sum ANOVA P< ph The ph of all five suspensions were determined by ph meter and the results shown in table no. 11.The average ph of taste masked suspension was found 6.11 to Table 11: ph of different Suspension formulations Suspension Formulation ph Average± SD S ± S ± S ± S ± S ± Viscosity Viscosity of different taste masked suspension formulations was found ± 4.17 to ± 3.50 cp. Results shown below in table no. 12. Table 12: Viscosity of different Suspension formulations Suspension Formulation Viscosity(cps) Average± SD S ± 4.17 S ± 5.75 S ± 3.50 S ± 4.86 S ± 3.35 Sedimentation Volume (F) The sedimentation volume (F) was found near to 1 for all the suspension formulations. All the suspension formulations were stable for 14 days. Results are shown in table no.13.

10 Page502 Table 13: Sedimentation Volume (F) of different Suspension formulations Sedimentation volume (F) Suspension Formulation After 1 hr. After 24 hr. After 14 days S S S S S Particle size The particle size of suspensions was found in the range of ± 0.70 to ± 1.38 µm. The suspension with only drug was shown the particle size and the other suspensions with DRC were shown the particle size near to µm. Results are given below in table no. 14. Figure 4: Photomicrograph of prepared suspension S 3. Table 14: Particle size of different suspension formulations Suspension Formulation Average Particle size (µm) Average± SD S ± 0.70 S ± 1.26 S ± 2.21 S ± 1.38 S ± 0.60 Redispersibility All the suspension formulations showed the good redispersibility. Results are shown in table no. 15. Table 15: Redispersibility of different suspension formulations Suspension Formulation Redispersibility S S S S S = Poor, ++ = Good, +++ = Better, ++++= Excellent Drug content The drug content in different suspension formulations S 1 to S 5 was in determined in acidic ph 1.2 and salivary ph 6.8. The suspension with only drug (S 1 ) was shown maximum drug content i.e % and the others suspensions with DRC were shown the drug content near to 94.5%. at ph 1.2. At ph 6.8 the drug content was in the range of ± 1.16 to ± The suspension with only drug was shown 99.17% but others suspensions with DRC shown approximately 29% drug content. Which means the DRC was stable at saliva ph. Results are given below in table no. 16 & 17.

11 Page503 Table 16: Drug Content in different suspension formulations at ph 1.2 Suspension Formulation % Drug content at ph 1.2 Average± SD S ± 0.55 S ± 0.54 S ± 0.16 S ± 0.61 S ± 0.34 Table 17: Drug Content in different suspension formulations at ph 6.8 Suspension Formulation % Drug content at ph 6.8 Average± SD S ± 0.82 S ± 1.75 S ± 1.18 S ± 1.79 S ± 1.16 Assay of Oral taste masked suspension The assay of different formulations of oral taste masked suspensions were carried out in 0.1 HCl and the % drug content was found out shown in table no. 18. The drug content in 0.1 N HCl was found in the range of ± 0.60 to ± 0.08 %. Table 18: Assay Results in different suspension formulations in 0.1 N HCl Suspension Formulation % Drug content Average± SD S ± 0.08 S ± 0.37 S ± 0.65 S ± 1.80 S ± 0.60 In-vitro dissolution In vitro dissolution of different ratio of taste masked levofloxacin- Tulsion 335 suspension formulations was carried out in 0.1 N HCl solution for 60 minutes. It was observed that the suspension with only drug was shown % drug release and the others suspension formulation were shown the drug was released in the range of to %. Results are given below in table no. 19 and figure 5. Table 19: Cumulative % Release of different suspension formulations at Different Time Intervals. Cumulative % Release at Different Time Intervals Time S 1 S 2 S 3 S 4 S 5 5 min min min min min min Figure 5: Cumulative % Release of different suspension formulations at Different Time Intervals.

12 Page504 In-vitro dissolution of marketed oral solution of levofloxacin: In vitro dissolution of marketed oral solution of levofloxacin was carried out in 0.1 N HCl solutions and the % cumulative release was determined for one hour. The dissolution results are shown below in table no. 20 and figure 6. Table 20: Cumulative % Release of marketed oral solution formulations at Different Time Intervals. Time Cumulative % Release at Different Time Intervals 5 min min min min min min Figure 6: Release of Drug at different Time Intervals from marketed oral solution. Dissolution Profile Comparison In vitro dissolution profile of all formulated Suspension formulations were compared with marketed preparation of levofloxacin hemihydrates. The results are shown in table no. 21 and figure 7. Figure 7: Comparison of In-vitro release profile with marketed oral solution of levofloxacin Table 21: Comparison of In-vitro release profile with marketed oral solution of levofloxacin Cumulative % Release at Different Time Intervals Time S 1 S 2 S 3 S 4 S 5 Marketed Sample 5 min min min min min min

13 Page505 Cumulataive % Release All the formulations were shown the almost similar dissolution profile but formulation S2, S3 and S5 (96.25%, 98.95% and 98.94%) were more similar to marketed sample (99.02%). Similiarity Factor The in vitro dissolution profile of formulated oral suspension of levofloxacin hemihydrates with SDRC were prepared and matched with innovator product by calculating the similarity factor. A model independent approach was used to estimate the similarity factor f2 to compare the dissolution profile of S3 with innovator s preparation. The similarity factor (f) is given by the following equation: f= 50 log {[1+ (1/n) Σ t=1n (Rt-Tt) 2] } Where n = no of time points, Rt = dissolution value of the reference batch at time t, Tt=dissolution value of the test batch at same time point. Similarity Factor f, Number of time points, n = 6 Number of points in Rt and Tt must be the same and must be the similar to n. Table 22: Calculation of Similarity factor Time Test Reference Reference - Test (Rt-Tt)2 Similarity Factor F SUM Time (in minutes) S3 Marketed Sample Figure 8: Release Profile of SDRC 3 and Marketed Sample. Similarity Between dissolution profiles of Optimized formulation (S 3 ) and marketed product was found to be % which is within range and complies with the standards. The standards for similarity factor are The data for calculation of f were shown in Table no.22 and Figure 8. Stability study Suspension of S 3 was kept for accelerated stability study at o C and % RH for 1 month in stability chamber. After a period of one month, the samples were observed for any change in physical parameters. It was observed that any change in color. It was also noted that suspension was free of any kind of bad odor. Results obtained from the evaluation after stability studies are shown in Table 23.

14 Page506 Table 23: The Evaluation after Stability Studies Evaluation Parameters Initial After 1 month Color Yellow Yellow Taste Not bitter Not bitter Bad Odor Not any Bad odor Not any Bad odor ph Viscosity (cps) Sedimentation Volume Redispersibility Assay % In- vitro release % CONCLUSION: Ion exchange resin, Tulsion-335, was successfully mask the taste of levofloxacin hemihydrates all ratios but DRC with 1:2 ratio was selected for the formulation of suspension due to high yield and sufficient taste masking. DRC were evaluated for the parameters viz. percentage yield, drug loading, tastemasking, particle size etc. Formulated tastemasked suspension with selected DRC were formulated in triplicate and evaluated for appearance, viscosity, drug content, and assay, In-vitro release and sedimentation ratio. Based on the evaluation data obtained after one month stability study, it was concluded that the formulated suspension with SDRC was successfully taste masked, stable and reproducible in nature. The recommended future research in this area may be formulation of taste masked sustained release suspension dosage form to compliance the pediatric patients. Sustained release suspension formulations are beneficial to avoid fluctuation in plasma concentration of drug and also less the dose frequency. ACKNOWLEDGMENT The author is thankful for the cooperation and facilities provided by the institute with kind permission of Prof.Sanjeev Thacker, Director/Principal, Seth G.L. Bihani S. D. College of Technical Education, Sri Ganganagar (Raj).The author is also grateful to the Morepen Laboratories,Chandigarh, and Thermax Limited, Pune, India for exgratis samples of, levofloxacin hemihydrate,tulsion-335 respectively. REFERENCES 1. Shaikh Sanaa, Athawale Rajania, Nadkar Sumedhab and Bharati Maheshb: Formulation And Evaluation Of Taste Masked Oral Suspension Of Dextromethorphan Hydrobromide, Int. J. Drug Dev. & Res., 2012, 4 (2): Ion Exchange Process,Luminar Softening Education, Available at http,// (Accessed on December 2, 2013) 3. Ion Exchange Resin. Available at: ((Accessed on December 12, 2014) 4. Ion Exchange Reaction. Available at: 96/ion-exchange-reaction (Accessed on November22, 2014) 5. Ion Exchange Resin. Available at: /Chemicals/Ion-Exchange-Resins.aspx. 6. Irwin WJ, Belaid KA, Alpar HO. Drug delivery by ion exchange: Part III. Interaction of ester pro drugs of propranolol with cationic exchange resins. Drug Dev. Ind. Pharm., 1987, 13, Suthar, A. M. and Patel, M. M. Development of Taste Masked Liquid Formulation of Tinidazole using Ion Exchange Resin Complexes. Journal of Pharmaceutical Science and Technology, 2010, 2 (9), Akkaramongkolporn, P., Ngawhirunpat, T., Nunthanid, J., and Opanasopit, P., Effect of a Pharmaceutical Cationic Exchange Resin on the Properties of Controlled Release Diphenhydramine Hydrochloride Matrices using Methocel K4M or Ethocel 7cp as Matrix Formers. AAPS Pharm Sci Tech,2008, 9(3), Halder, A., and Sa, B., Sustained Release of Propranolol Hydrochloride Based on Ion-Exchange Resin Entrapped within Polystyrene Microcapsules. J Microencapsul, 2006 Dec; 23(8), Xiaofeng, Y., Hongfei, L., Changshan, S., Shuangshuang, S., Xiao F., and Yan, H., A Simple and Novel Method for Preparing the Taste Masking Levofloxacin Microsphere Suspension. African Journal of Pharmacy and Pharmacology,2012, 6(22), Shabouri EI MI. Positively Charged nanoparticles for the oral bioavailbility of cyclosporine A. Int. Pharm 2003; 249: A.S. shete, A.V. yadav, A.P. Dabke, S.S. Sakhare, Formulation and Evaluation of Hydrotropic solubilization based suspension of Griseofulvin, IJPSR, 2010; 1 1 : Liu Z, Richard C, Wu XY, James RB, Reina B, Andrew MR, A study of doxorubicin loading onto and release from sulfopropyl dextran ion-exchange microspheres. Int. J. Pharm., 2001, 77: Pisal, S, Zainnuddin, R, Nalawade,P,Mahadik, K, kadam, S. Molecular Properties of ciprofloxacin indion 234 complexes. AAPS Pharma Sci Tech., 2004, 5, Liu Z, Wu XY, James RB, Reina B. Synthesis and Characterization of Surface-Hydrophobic Ion-Exchange Microspheres and the Effect of Coating on Drug Release Rate. Int. J. Pharm., 2000, 89:

15 Page Warad shubhangi, Warad Pallavi, Solunke Rahul, Suthar Ajay; Taste masking of Highly Bitter Drug Zopiclone using ion Exchange Resin, Universal Journal of Pharmacy, 2013, 02 02, : Rashmi D, Rajesh S, Formulation and in vitro evaluation of taste masked orodispersible tablet of mutoclopramide hydrochloride using indion 204. Int. J. Chem. Tech. Res., 2010, 2: Akbari B.V., Patel B.P., Dholakiya R.B., Shiyani B.G., Lodhiya D.J.:Development And Evaluation Of Taste Masked Suspension Of Prokinetic Agent By Using Ion Exchange Resin, IJPRIF, 2010, 2(1), Blase, C.M., Shah, M.N., Taste masked pharmaceutical suspensions for pharmaceutical actives. Eur. Pat. Appl. EP , 18 August Pavan. A. Kulkarni, Master of Pharmacy, Thesis Entitled Formulation and Evaluation of Taste Masked Fast Dissolving Tablets and Dry Suspension of Some Macrolide Antibiotics by Various Techniques Department of Pharmaceutics, Bharathi College of Pharmacy, Bharathinagara, Fu Y, Yang S, Jeong SH, Kimura S, Park K. Orally fast disintegrating tablets: developments, technologies, tastemasking, and clinical studies. Critical Reviews in Therapeutic Drug Carrier Systems. 21(6): (2004). 22. T.N. Patel,, R.P. Patel, B.V. Patel, : Taste Masking of Topiramate by Newer Range of Ion-Exchange Resin, International Journal of Pharmaceutical Sciences and Nanotechnology,2010, 3(3), United States Pharmacopoeia 28 NF 23 (2005) The Official Compendia of Standards. Published by United States Pharmacopeial Convention, Inc. Rockville, MD, Asian Edition, Printed in Canada by Webcome Ltd. Toronto, Ontorio 24. Augello Michael, Edible PGA coating composition, US B2, Available from: applications-ion-exchange-resins-update (Accessed on December 12, 2014)