Formulation development and Evaluation of Colon Specific Delivery System of Anti- amoebic Drug (Tinidazole) using different Polysaccharide carriers

 

Preetha Mathew, Shajan Abraham, Sneha Sabu, Namitha Navas*, Sherin Koshy,

Shahana S, Elessy Abraham

Nazareth College of Pharmacy, Othera P.O Thiruvalla, Kerala, India 689646.

*Corresponding Author E-mail: namithanavas97@gmail.com

 

ABSTRACT:

Amoebiasis is an infection of the large intestine caused by Entamoeba histolytica. Tinidazole is the preferred drug used in the treatment of intestinal amoebiasis. The conventional tablet dosage form provides minimal amount of drug in the colon with undesirable adverse effect due to variation in the transit time. Hence, to target the drug directly to the site of action in the colon, there is need to develop colon targeted drug delivery systems that will enhance the therapeutic drug level, increases the bioavailability of active medicament and reduce the dose of drug. The fast disintegrating core tablet of Tinidazole was prepared by direct compression method. The core tablet was evaluated for hardness, thickness, Friability, weight variation, drug content, in vitro disintegration time and in vitro drug release studies. Using the optimized formulation (C3), different formulations (F1-F6) of coated tablet was prepared by using different polymers like chitosan and xanthan gum. The formulated coated tablet were evaluated for various parameters like for hardness, thickness, Friability, weight variation, drug content, swelling study and in vitro dissolution study. The optimized formulation F3 shows 6.24% drug release in Stomach and Small Intestine and maximum drug release up to 96.53% in the colon. The kinetic data analysis of formulations indicated that it fits to Korsmeyer -Peppas Model and follows zero order release kinetics. The mechanism of drug release from the tablet followed non-Fickian (super case-11) transport. The stability studies of the optimized formulation were investigated as per ICH guidelines. There were no significant changes in thickness, hardness, weight variation, friability, drug content and in vitro drug release. These findings suggest that compression coated tablet using polysaccharide carriers provide more site specific delivery, reduced degradation and release of drug in stomach and small intestine.

 

KEYWORDS: Amoebiasis, Polysaccharide carriers, Chitosan, Xanthan gum, Compression coating, Tinidazole.

 

 


INTRODUCTION:

Oral solid dosage forms has been one of the most suitable and widely accepted by the patient for the delivery of therapeutic active drug. The traditional tablet dosage form provides minimal amount of drug in the colon with undesirable adverse effect due to variation in the transit time. Therefore in order to target the drug directly to the site of action in the colon, there is need to develop colon targeted drug delivery systems that will increases the therapeutic drug concentration, thereby increases the bioavailability of active medicament and reduce the dose of drug.1,2

 

Tinidazole is a drug used against protozoan infections eg; trichomoniasis, giardiasis, and amebiasis..etc.

 

Targeted delivery of drug to the colon is highly desirable for local treatment of a variety of bowel diseases such as ulcerative colitis, crohn’s disease amoebiasis, colonic cancer, local treatment of local colonic pathologies, and for the systemic delivery of protein and peptide drugs.

 

 

Need of Colon Targeting:

·       Targeted drug delivery to the colon would ensure direct treatment at the disease site, lower the frequency of dosing and fewer systemic side effects.

·       Minimizes extensive metabolism of steroids.

·       A number of others serious diseases of the colon, e.g. colorectal cancer, might also be capable of being treated more effectively if drugs were targeted to the colon.3

 

Materials:

Tinidazole Chemdyes, Gujarat, Chitosan Yarrow Chemicals, Mumbai, Xanthan gum Chemdyes, Gujarat HPMC K100 M Fortune Chemicals, Malappuram, Lactose Nice Chemicals, Kottayam, Sodium starch glycolate Yarrow Chemicals, Mumbai, Starch Fortune chemicals, Malappuram, Magnesium Stearate Nice Chemicals, Kottayam 9, Talc Nice Chemicals, Kottayam.

 

Methods:

Identification of Drug:

The monograph of Tinidazole signified that the substance under examination was intimately mixed with potassium bromide. FTIR spectrum of the sample was taken using potassium bromide pellet method. The spectrum of test specimen was recorded over the range from 4000cm-1 to 500cm-1 and compared with the corresponding USP reference standard.4

 

Organoleptic Evaluation:

Organoleptic properties of drug like color, appearance and odor was observed and recorded5.

 

Determination of Melting Point:

The melting point of drug was determined by capillary tube method. The drug was filled to capillary tube which has one end sealed. The filled capillary tube was placed inside the melting point apparatus and the temperature at which drug melted was noted.6

 

Determination of Solubility of Tinidazole:

Solubility of Tinidazole was checked in various solvents like water, phosphate buffer pH 7.4, 6.8, methanol and 0.1N HCL. 100mg of drug was accurately weighed and transferred into a stoppered tube containing 0.1ml of solvent. If completely dissolved, the drug is said to be very soluble. If insoluble, added 0.9ml of solvent to it and is said to be freely soluble on complete dissolution. Otherwise, added 2ml of solvent to the same. The drug, if completely dissolved in the solvent, then it is said to be soluble. If insoluble, further 7ml of solvent was added and observed to be sparingly soluble on complete dissolution. On further addition of 10ml of solvent it is said to be slightly soluble, if completely dissolved. If it is not completely dissolved in the above solution, accurately weighed 1mg of drug and added 10ml of solvent. If the solvent dissolves the drug, it is said to be very slightly soluble.6

 

Analytical Method Used in the Determination of Tinidazole Determination of λmax of Tinidazole:

10µg/ml solution of Tinidazole was taken in specific buffer solution (pH 1.2, pH 7.4, Ph 6.8) using serial dilution technique and scanned in range 200 - 400nm using UV spectrometer to find out the wavelength of maximum absorbance.

 

Preparation of calibration curve of Tinidazole:

100mg of drug was accurately weighed and dissolved in 100ml of 0.1N HCl, 7.4 PH, and 6.8 PH in 10ml volumetric flask, to make (1000µg/ml) standard stock solution (1). Then 1ml stock solution (1) was taken in another 10ml volumetric flask to make (100µg/ml) standard stock solution (2), then again 1ml of stock solution (2) was taken in another 10ml volumetric flask and then final concentrations were prepared 2, 4, 6, 8, 10, 12, 14, 16, 18, and  20µg/ml with 0.1N HCl, 7.4 pH, and 6.8 pH. Absorbance was measured in UV spectrometer at 278, 320 and             318nm wavelength.

 

Compatibility studies:

Excipients are any substance other than active or prodrug included in the manufacturing process or contained in the finished product.6

 

FTIR Study:

The IR spectra were recorded using FTIR spectrophotometer. The samples were prepared by mixing the drug and the excipients in 1:1 ratio and the mixtures were stored in closed containers for 1 month. FTIR spectrum of the samples was taken using potassium bromide pellet method. The physical mixtures of Tinidazole and excipients were scanned in the wavelength region between 4000 and 500 cm-1 and compared to check compatibility of drug with           excipient. 7

 

DSC

DSC study was carried out using DSC-60 instrument (Shimadzu) to check the compatibility of ingredients. The samples were prepared by mixing the drug and the excipients in 1:1 ratio. Accurately weighed samples were sealed in aluminum pans and analyzed in an inert atmosphere of nitrogen at flow rate of 25ml/min. A temperature range of 0°C to 300°C was used, and the heating rate was 10°C/min. DSC thermograms of pure drugs and physical mixtures of drugs and excipients were studied for their interaction.7

 

Precompression parameters of core and coating material: Angle of repose (θ):

Angle of repose was determined by measuring the height, radius of the heap of the powder blend. A cut system funnel was fixed to a stand and bottom of the funnel was fixed at a height of 2cm from the plane. Powder blend was placed in funnel and allowed to flow freely and measured the height and radius of the heap7.

 

Tan (θ) = h/r Where, h = height of heap,

r = radius of heap

 

Bulk density (Db):

It is the ratio of total mass of powder to the bulk volume of powder. It was measured by pouring the weighed powder (passed through standard sieve # 20) into a measuring cylinder and the initial volume was noted. This initial volume is called the bulk volume. From this, the bulk density is calculated according to formula mentioned below. It is expressed in g/ml and is given by7

 

Db = M /V0

M - The mass of powder

Vo - The bulk volume of powder (ml)

 

Tapped density:

Tapped density is the bulk density of a powder which has been compacted by tapping or vibration. Tapped density was determined by placing a graduated cylinder containing a known mass of powder on a mechanical tapping apparatus, which is operated for a fixed number of taps (100) or until the powder bed volume has reached a minimum. The tapped density was computed by taking the weight of drug in cylinder and final volume.7

 

Tapped density = Weight of powder/ tapped volume Compressibility index (Carr’s index):

Another indirect method of measuring powder flow form bulk densities was developed by Carr. The percentage compressibility of a powder is a direct measure of the potential powder arch or bridge strength and stability. It is calculated according to the following equation7.

 

Carr’s index =Tapped density- bulk density/ Tapped density×100 Hausner’s ratio:

Hausner ratio is an indirect index of ease of powder flow. If the hausner’s ratio of powder is near to 1.25, indicates better powder flow. It is calculated by the following formulations7.

 

Hausner’s ratio= Tapped density/Bulk density Formulation of Core Tablet:

Core tablets of Tinidazole were prepared by direct compression technique. Sodium starch glycolate included in the formulation to obtain the Tinidazole tablets with fast disintegrating characteristics (disintegrating time < 1min). All the ingredients were weighed and thoroughly mixed and passed through a mesh no 60 to ensure complete mixing. The thoroughly mixed materials were then directly compressed into tablets using 6 mm round, flat and plain punches on a single station tablet machine. Tablet quality control tests such as weight variation, hardness, friability, thickness, and dissolution studies were performed for the core tablets given on Table no.18,9.

 

Table No. 1: Composition of core tablet

Ingredients

Quantity(mg)

C1

C2

C3

Tinidazole

150

150

150

Lactose

38

35

32

Sodium starchglycolate

6

9

12

Magnesiumstearate

3

3

3

Talc

3

3

3

 

Evaluation of core tablet Thickness:

The thickness of six tablets was measured using vernier calipers. The extent to which the thickness of each tablet deviated from ±5% of the standard value was determined.9

 

Hardness:

Hardness of the Tablet was determined by Monsanto Hardness Tester. Six tablets from each batch were selected and evaluated, and the average value with standard deviation was recorded.9

 

Weight Variation:

Twenty tablets were selected at random and average weight was determined. Then individual tablets were weighed and the individual weight was compared with the average weight. The percentage deviation was calculated and checked for weight variation. Using this procedure weight variation range of all batches of formulations was determined and recorded. Weight variation was calculated by using following formula.10

 

%Weight variation= Individual wt. of tablet- Average wt. of tablet

Average wt. of tablet*10

 

Friability:

The friability of Tablets was performed in a Roche Friabilator. Ten tablets were weighed together and then placed in the chamber. The friabilator was operated for 100 revolutions and the tablets were subjected to the combined effects of abrasion and shock because the plastic chamber carrying the tablets drops them at a distance of six inches with every revolution. The tablets are then dusted and re-weighed. The % friability (F) was calculated using following formula:

F = (W1-W2 / W1) × 100

 

Where,

W1 is the initial weight of the sample of twenty tablets before the test. W2 is the weight of the tablet after the test.

 

In vitro Disintegration Study:

The process of breakdown of a tablet into smaller particles is called as disintegration. The in vitro disintegration time of a tablet was determined using disintegration test apparatus as per I.P. specifications. Place one tablet in each of the 6 tubes of the basket. Add a disc to each tube and run the apparatus using pH 6.8 (simulated intestinal fluid) maintained at 37±2°C as the immersion liquid. The assembly should be raised and lowered between 30 cycles per minute in the pH 6.8 maintained at 37±2°C. The time in seconds or minutes taken for complete disintegration of the tablet with no palpable mass remaining in the apparatus was measured and recorded.10

 

Preparation of Tinidazole:

Compression Coated tablet The formulated Core tablets were compression coated by using different polysaccharide carriers in combination with time dependent hydrophilic swellable i.e. Xanthan gum, Chitosan and hydrophilic swellable polymer HPMC K100M). The compression coat powder material was prepared by using wet granulation method using starch paste as binder. The half amount of coat was placed in the Die and then the Core tablet was carefully positioned in the center of die and then the other half portion of coat material was added. The coating material was then compression around the core tablet by using 12mm round, flat, plain punches by using Constant compression force 6 - 6.5kg/cm .

 

Evaluation of compression coated tablet: Thickness:

The thickness of six tablets was measured using vernier calipers. The extent to which the thickness of each tablet

deviated from ±5% of the standard value was determined.10

 

Hardness:

Hardness of the Tablet was determined by Monsanto Hardness Tester. Six tablets from each batch were selected and evaluated, and the average value with standard deviation was recorded.10

 

Friability:

The friability of Tablets was performed in a Roche Friabilator. Ten tablets were weighed together and then placed in the chamber. The friabilator was operated for 100.

 

Revolutions and the tablets were subjected to the combined effects of abrasion and shock because the plastic chamber carrying the tablets drops them at a distance of six inches with every revolution. The tablets are then dusted and re-weighed. The % friability (F) was calculated using following formula:

 

F = (W1-W2 / W1) × 100

 

W1 is the initial weight of the sample of twenty tablets before the test. W2 is the weight of the tablet after the test.

 

Weight Variation:

Twenty tablets were selected at random and average weight was determined. Then individual tablets were weighed and the individual weight was compared with the average weight. The percentage deviation was calculated and checked for weight variation. Using this procedure weight variation range of all batches of formulations were determined and recorded. Weight variation was calculated by using following formula.

 

%Weight variation= Individual wt. of tablet- Average wt. of tablet/Average wt. of tablet*100 Content Uniformity Test10

 

Ten tablets were finely powdered and quantities of powder equivalent to 100mg of Tinidazole was accurately weighed and transferred to 100ml volumetric flask containing approximately 50ml of methanol and allowed to stand for 6 hrs with intermittent sonication to ensure the complete solubility of the drug. The volume made up with pH 6.8 phosphate buffer and mixed thoroughly. The solutions were filtered through 0.22µ membrane filter. The sample analysis for drug content was done at 318nm by using uv- visible spectroscopy.

 

In vitro Swelling Study:

The extent of swelling was measured in terms of percent weight gain by the tablet. The swelling behavior of all the formulations was studied. One tablet from each formulation was kept in petri dish containing pH 6.8 phosphate buffers. At regular interval of time the tablet was withdrawn, blotted with tissue paper and weighed. Percent weight gain by the tablet was calculated using formula,

 

Swelling index = 100 (W2 - W1)/ W1

 

Where; W1 = initial weight of the tablet. W2 = final weight of the table

 

Stability Studies:

Stability study was done to check out the quality of drug substance or product varies with time under the influence of a variety of environmental factors such as temperature, humidity, and light; to establish a retest period for the drug substance or a shelf life for the drug product and recommended storage condition. Here the tablets were loaded at accelerated condition at 40˚C±2˚C and 75% RH for 6 six months in a stability chamber. Sample were withdrawn after 30 and 60 days and analyzed suitably for the drug content and dissolution characteristics.11

 

RESULT AND DISCUSSION:

Identification of drug:

FTIR studies were carried out for Tinidazole and for the drug-excipients physical mixtures. The FTIR spectrum of Tinidazole exhibited peak signals at 3130, 2956, 1602, 1522, 1479, 1428, 1365, 1264, 1126 and 1026cm- 1 due to = CH stretching, C-H stretching, C=C and C=N stretching of imidazole ring, CH bending, C-C stretching, N=O symmetric stretching, C-O, S=O and C-N stretching. The were no significant changes in the frequency of the functional groups of Tinidazole. So, the drug was compatible with all excipients

 

Fig.No.1:. FTIR studies were carried out for Tinidazole and for the drug-excipients physical mixtures

 

Organoleptic Evaluation:

·       Colour: White or pale yellow

·       Odour: Odorless or almost odorless

·       Appearance: Crystalline powder

 

Determination of Melting Point:

The standard melting point of Tinidazole is in the range of 127-128°C. The observed value was 128°C which is within the range as per official monograph. So the drug was identified as Tinidazole.

 

Determination of Solubility of Drug:

The solubility was determined by dissolving the drug in different solvents like water, Methanol, Acetone, 0.1N HCL, Phosphate buffer saline 7.4 and 6.8. The results of solubility analysis are given in the It was very slightly soluble in water, sparingly soluble in methanol and soluble in acetone, 0.1N HCL, Phosphate buffer saline 7.4 and            6.8.

 

Analytical method for the determination of tinidazole:

Determination of λ max of Tinidazole:

The 10µg/ml sample was prepared and scanned between 200 to 400nm. The drug showed maximum absorption at 278nm in 0.1N HCL, 320nm in phosphate buffer 7.4 and 318nm in 6.8 buffer.

 

FTIR:

FTIR studies were carried out for drug [Tinidazole] and for the drug-excipients physical mixtures. There were no significant changes in the frequency of the functional groups of Tinidazole. So, the drug was compatible with all excipients.

 

DSC studies:

The DSC studies were carried out for drug [Tinidazole] and drug-excipients physical mixtures. The recorded DSC thermograms showed the profile of Tinidazole with melting point at 128˚C. Drug when combined with excipients, showed melting point at 128ºC. The melting point remains almost the same, indicated that the drug and excipients are compatible with each other.

 

Post compression parameters of coated tablet:

Hardness of coated tablet:

Hardness of the compression coated tablet was measured by using Monsanto apparatus and results showed that all the formulations possessed good hardness.

 

Thickness of coated tablet:

Thickness of coated tablet was determined using digital vernier caliper and it was found to be in the range of 4.49- 4.89mm.

 

Weight variation test:

Weight variation of the tablet should not be exceeding above 5%. All batches pass the weight variation test as they showed average weight variation below 5%.

 

Drug content:

The percentage drug content of compression coated tablet was found to be within limits. Percentage drug content value of Tinidazole was found in the range from 87.17±0.17 to 95.47±0.04.

 

In vitro Swelling study:

As time increases the swelling index was increased, because weight gained by tablet was increased proportionally. The direct relationship was observed between swelling index and gum concentration, as gum concentration increases, swelling index was increased. Given in Table no.2:

Table No. 2: Results for swelling index of coated tablet

Time (hr)

%Swelling index

F1

F2

F3

F4

F5

F6

1

49

51.56

52.53

44.94

43.92

47.98

2

53.41

54.15

56.81

48.38

45.45

55.41

3

54.46

55.59

57.38

51.43

47.38

60.61

4

55.89

57.72

59.62

53.12

50.41

64.70

5

61.39

63.41

64.59

55.45

55.13

61.68

6

64.10

66.73

68.91

59.45

61.23

63,19

7

66.61

68.83

72.71

61.05

64.29

67.23

8

70.86

73.21

74.91

61.98

66.85

68.34

 

In vitro drug release study of coated tablet:

Dissolution testing of compression coated tablet of Tinidazole in 0.1 N HCl, phosphate buffer pH 7.4 and pH 6.8 in the presence of probiotic culture were carried out. The percent drug release for all batches in phosphate buffer pH 1.2, pH 7.4 and pH 6.8, From above percent drug release study it is clear that formulation F1-F3 shows less than 10% drug release in Stomach and Small Intestine and maximum Drug release up to 96.53% in the targeted site.

 

Stability study:

Hardness, friability, weight variation and drug content values are analyzed periodically as per ICH guidelines through accelerated stability studies for optimized formulation.

 

REFERENCES:

1.      Tiwari Vaibhav, Dr. Dangi J. S et al . Preparation and In-vitro and In-vivo evaluation of colon targeted delivery of antiamoebic drug: an approach to reduce dose. Research Journal of Pharmacy and Technology. 2012 dec; 5(12): 1588- 95: doi: 10.5958/0974-360X .

2.      AD.kajale , Bakade BV, Channawar MA, Gawande SR, Bakal RL and Chandewar AV et.al. Colon targeted drug delivery: a review. Research Journal of Pharmacy. and Technology. 2010 mar; 3(1):45-49: doi: 10.5958/0974-360X.

3.      Shammika p, aneesh tp, vidya viswanad. Formulation and evaluation of synthesized quinazolinone derivative for Colon specific drug delivery. Asian journal of pharmacy and Research. 2016 dec;3(10) :207-12: doi:10.22159/ajpcr.2017.v10i3.16024.

4.      Sumithra S ,Vaidivu R, Radha R.Colon targeted drug delivery system of phytoconstituents. Research Journal of Pharmacy and Technology. 2019 ; 12(7):3144-50: doi: 10.5958/0974-360X

5.      Mukund G, Tawar,PD ,Chaudari, Design and dissolution study of Colon specific drug delivery system of tinidazole. Research journal of. Pharmacy and Technology. 2009 dec ;2(4): 862-64:doi: 10.5958/0974-360X

6.      Krithika R. Iyengar,M Komala, S.Satheeshkumar. Colon specific drug delivery system- Different systems and approaches: A review. Research Journal of Pharmacy and Technology.2020;13(12): 6248-58: doi: 10.5958/0974- 360X

7.      Yasmin Begum M, Kiran Kumar Bandarupalli, Sirisha Ch, Kavitha A, Sudhakar M. Studies on the Development and evaluation of colon targeted mesalamine tablets based on eudragit L100 Chitosan Interpolyelectrolye Complexes. Research Journal of Pharmacy and Technology.2017;10(5):1289-96: doi: 10.5958/0974-360X .

8.      Deshkar Sanjeevani,Talole Kranti , Shirsat Ajinath , Bhalerao Aparna, Shirolkar Satish Padm and DY Patil. Development of colon targeted delivery of ketoprofen using natural gums as carrier:.Research Journal of Pharmacy and Technology. 2009 Dec;2(4): 771-76: DOI: 10.5958/0974-360X .

9.      Anglina Jeniffer Samy, Elango k, Ramesh Kumar K, Ramesh Kumar .N. Formulation and evaluation of Dicyclomine Hydrochloride Matrix Tablets For Colon specific Drug Delivery. Research Journal of Pharmacy and Technology.2012 Apr ;5(4): 494-496: doi: 10.5958/0974-360X

10.   Vijayakumar V. Alange and Raghavendra V. Kulkarni.Colon Targeted Drug Delivery through functionally modified natural polymers. Research Journal of Pharmacy and Technology.2017;10(6):1853-57:doi: 10.5958/0974- 360X

11.   Mihir K. Patel, Dr. Amit Roy, Sanjib Bahadur, Shashank Kukreja, Monika Bhairam. Colon Targeted Drug Delivery: Approaches and Newer Technology. Research Journal of Pharmacy and Technology 2012 sep; 5(9):1154- 60 :doi: 10.5958/0974-360X

 

 

 

Received on 10.03.2021            Modified on 22.08.2021

Accepted on 10.12.2021           © RJPT All right reserved

Research J. Pharm. and Tech 2022; 15(9):4093-4098.

DOI: 10.52711/0974-360X.2022.00687