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The main aim of the project is to Load Ibuprofen drug in to prepared silica and to observe the drug release in a single step process . Silica was prepared with Sodium dodecyl sulphate, which is anionic surfactant (SDS) and Tween20, which is Polysorbate surfactant and with Ammonia.
Ibuprofen Sodium (IBU-Na) is used as drug to load in silica. By loading this drug in to prepared silica and successfully loaded drug in to silica. Then found the Invitro drug release.
Sodium dodecyl sulphate prepared silica dug is loaded successfully and surface area is measured. Surface area found as less than 1, but absorbance of the drug release was good. Tween20 prepared silica drug is loaded successfully as in SDS and the surface area in tween20 less than 1, but drug release was good.
Ammonia samples, Prepared in 3 batches like B1, B2, B3. For each batch drug loaded successfully and surface area is measured. Silica prepared with ammonia shows better surface area than SDS and Tween20. This sample shows 26.1 m2/gm and the drug release is also shows good performance with ammonia because the drug having sodium salt and ammonia having alkaline properties. By comparing all't' values these Ammonia samples shows quick release of drug.
Silicon is the one of the burgeoning mineral in the earth crust. Silica is mostly useful in the human activities now days. In general silica is found in several natural ways like in clay, glass and chemically derived the products like silica, ceramics. Silica and silicates are also available in the form of an amorphous white powder which is made synthetically, by two methods 1) pyrogenic process and 2) wet process which is done by precipitated silica or gels. This amorphous silica from the ancient time it is used in the food products, personal care products, plant protection .4
Siliceous minerals found in different types of structure. Silica and combined minerals are structurally having tetrahedral arrangement of four oxygen atoms surrounded by silicon central atom (SiO4). The average each oxygen is distributed by silicon's in two tetrahedral in the SiO2 stoichiometry of silica. Sharing of the silica edges is terminated and sharing faces don't occur by poor stability. Some corners remain undistributed by the possibility of linking tetrahedrons. Each undistributed oxygen atom gives a negative charge to the anionic group. 4
It is the famous technique to produce silica. It is an easy process by the continuous flame hydrolysis of silicon tetrachloride, SiCl4. Then SiCl4 changes into gas after that SiCl4reacted with hydrogen and oxygen. Water acts as an intermediate and it reacts with SiCl4 to form silicon.
After this exothermic chemical reaction it generates heavy heat requiring cooling of the reaction products. Hydrochloric acid, is the by product which is separated from silica powder and is separated and recycled and the removed powder is used for manufacture of silicon tetrachloride
These concentrations of the reactants show some variations and control the physical and chemical properties such as particle size distribution and structure, surface area of the thermal silica. The use of silanes makes the adjustment to make the final product.
(II) Precipitated Silica:
In this method of preparation we use alkali silicate, sodium silicate and acid. It is prepare in different steps. First, sulphuric acid is taken in to a vessel containing water and stirred vigorously. In different cases existed pH is set. Then this all components are feeding in to the reactor like this process it done in same time intervals. Normally silica is manufactured at the pH values greater than 7, and silica gels are manufactured at pH less than 7.
Na20 X 3.3 SiO2 + H2SO4 3.3 SiO2 + Na2SO4 + H2O (4)
The obtained precipitation obtained is a suspension. The obtained filter cake is washed with sodium sulphate and then it is resuspended and allowed for spray dry. According to the drying technology and the practical size of the silica it is properly milled and made in to fine particles which obey the particle size of the silica. Even precipitated silica converted into hydrophilic to hydrophobic by treating with chemicals.
(III) Silica gels:
This method of preparation we use alkali silicate, sodium silicate and acid. Silica gels are prepared by the precipitation method. The preparation of silica gels is reacted in small vessels. Raw materials which are used are taken into mixers in short time and mixed to form silica hydrosols. The pH of the formed hydrosols is less than 7. The given silica is mainly dependent on the pH. If the pH of the formation increases the silica gel formed will be lower. Silica gel follows the aging technology to modify the gels. In this process the silica gels formed in to some lumps make sure the lumps are crushed and enter in to further process. By finishing this aging silica should be washed to remove the soluble salts. Make the obtained silica well dried and it should be free from surface water. In the drying process there should be a chance of collapsing the particle size distribution and porosity so to maintain a desired particle size distribution milling should be done. 4
Usage of silica:
Silica is used in the formation of bone. Silica is found to be present uniquely in the areas of the active growth occurs grow smaller in relationship to the laying down of hydroxyapatite, or bone crystal, by the process that transforms pliable bone into a hard structure. With this silica acted as a regulating factor for the deposit of bone. Silica is also useful in the tissue disorder. 5
Characterization methods of silica:
Silica is characterized in different methods such as
1.2.1) Volume of the pore and pore size distribution:
Pore volume and specific evaluation methods are not explained clearly. Normally silica's pore volume is known to be (a) surface roughness, (b) the void volume (C) The aggregates or particles calculating micro or sub microscope volume. Pore volume can be determined by mercury porosimetry and the BJH method. By the measured pressure P, a quantity of force required to fill mercury in to the pores of the silica sample. Then the required pressure is inversely proportional to the diameter of the pore. At the given pressure the volume of mercury known then the pore volume can be calculated.
Specific surface of silica:
This specific surface of silica can be determined by Brunauer-Emmett-Teller (BET) adsorption method. The process is to cool the silica sample to the temperature of liquid nitrogen because in the low temperatures' nitrogen is adsorbed on silica surface. To find the perfect surface area BET method yields perfectly. So that it is not only easy to find the surface of the sample with nitrogen covered sample but also pores are filled. Then the distribution of the pores can be determined using Barrett-Joyner-Halendar method (BJH).
Cetyltrimethylammonium bromide surface area (CTAB):
The CTAB method comes from carbon black technology, and now using in silica technology. The CTAB method is worked up on the principle of adsorption of active molecules from aqueous solutions. The adsorption of the CTAB molecules is the outer, geometrical surface.
DBP number, oil Absorption:
It is involved by the absorption of Dibutylphtalate(DBP). This fine technique provides an indication of the full volume of the liquid that can be absorbed by the sample. Due to toxicity of DBP oil, paraffin oil is being replaced.
To find the dimensions of the silica there is a unique method which is electron microscopy. This provides the primary particle size, aggregates with certain limitations on the particle size distribution. Electron microscopic surfaces are calculated from particle size distributions, and these are to be measured with BET methods. There are several types in electron microscopy
Transmission Electron Microscopy (TEM):
Electrons are allowed to pass from a thin object and those electrons are having an interaction with prepared sample, which is used to produce an image. The resolution is 1000 which is more than that of light microscopy. The resolution of TEM is 0.2-0.3 nanometres (nm) and for light microscope is ~200 nm. TEM images will provide valuable information of structural composition in different silica samples because it is having high resolution. By this transmission electron microscopy it is possible to find the structure of silica.
Scanning Electron Microscopy(SEM):
It is not a microscopic technique that means it uses electromagnetic lenses for magnifying images. It produces a strongly magnified image with the help of electrons. These sharp electrons produce very good resolutions and focus. It is the great depth of focus which makes SEM superior to TEM for certain applications.
Atomic Force Microscopy (AFM): AFM is used to characterize surfaces of crystalline and amorphous, biological, synthetic products including crystals and films and also to characterize the microstructure of silica.
Surface chemistry characterization:
On the solid surfaces such as interior of micro pores, spatial inhibition, other equilibrium conditions, other chemical reactions may obtain. Chemical reactions are very important tool for characterizing solid surfaces. The yield will be good compared to the different products. To determine the silanol groups with lithiumaluminiumhydride (LiAIH4), a sample of silica is degassed in a vacuum and reacts with LiAIH4 at room temperature, the hydrogen determined volumetrically. By the other method sample reacts with an alkyl lithium or alkyl magnesium reagent followed by volumetric determination of the resulting alkane. After this reaction further reactions are done with chlorosilanes, alcohols, BCl3, AlCl3 or hexamethylendisilazane.
Different spectroscopies are used to analyse silica such as
Nuclear Magnetic Resonance Spectroscopy (NMR):
It is easy to find the surroundings on the silicon atom by oxygen atomsand hydroxyl group. The ratios of detected signals are correspond to the proportion to the various silica surroundings in the sample. It is possible with solid NMR method to ti distinguish the three main groups of silicon atom such as
Siloxane Bridges having chemical shift nearly 110 ppm
Isolated Terminal SiOH groups having chemical shift nearly 100 ppm
Geminal SiOH having chemical shift nearly 90 ppm
Infrared spectroscopy (IR):
IR is the method for differentiating between differentiating between various silanol groups. These groups are detected with IR bands in the spectrum are
Isolated SiOH at approximately 3745 cm-1
Vicinal SiOH at nearly 340 cm-1
Water bridges nearly at 3420 cm-1
Thermo analytical methods:
Thermal analysis is given to a group of methods that measure physical property of a substance. By differential thermal analysis (DAT) it is possible tomonitor the changes in enthalpy of a sample while at the course of temperature program. Thermogravimetry ((TG) and DTA both records the weight loss of the sample as a function of the temperature. By this weight loss information can be obtain on the possible course of degradation. Combination of DTA and TG are used to measure the effects of silica because thermal effects observed in DTA are negligible.
It is also difficult to make conclusions regarding the structure of a silica surface from the combination of DTA and TG alone.
Synthetic silica is amorphous. Silica not possesses three dimensional long range order like crystalline solids. X-ray diffraction method is not possible. Silica areas of short range order that can be determined by the evaluation of diffuse X-ray bands. Only in short range order these samples can be detected as low 200 degree centigrade using X-ray diffraction.
Loss on drying:
Loss on drying and loss on ignition are having important characteristic parameters that can be used to characterize the difference between silica. Precipitated silica and silica gels typically present a loss on ignition of more than 3%.4
Figure 2 : Ibuprofen structure 6
Name : Ibuprofen
Synonyms : : 2-(4-isobutylphenyl)propinoic Acid, 4-Isobutyl-Alpha-
Mol formula : (CH3)2CHCH2C6H4CH(CH3)COOH
Mol.Wt : 206.29
Melting point : 74 -770 C
Solubility : Partially insoluble
Ibuprofen (C13H18O2) was first discovered by Dr. Stewart Adams in United Kingdom with his colleagues. The chemical name of ibuprofen is 2-(4-isobutylphenyl) propanoic acid, which is an organic compound in the derivatives of Propionic acid.7
Ibuprofen having two mirror images forms which is a chiral molecule. Due to its structural formation no need to bother for separating enantiomers in the ibuprofen containing formulations.8
Ibuprofen is mainly known for its NSAID (non steroidal anti-inflammatory) properties by inhibiting active enzyme known as cyclo-oxygenase named as COX. These COX enzymes suspected to be suspected two more enzymes later by researches they found its true and recognised as COX-1 and COX-2 materialised. So that they recognised COX-1 is present in all levels of the body in all conditions because it is a consistent enzyme. Therefore the side effects arose from inhibition of the consistent COX-1 enzyme,and by inhibiting COX-2 enzyme it is having benefits therapeutically .7 The main mechanism is when the COX enzymes converts in to fatty acids to prostaglandins, at the end of the chain it reacts with COX enzyme then it causes pain, fever and inflammation. So Ibuprofen inhibits this chain and gives relief.8
1.3.1) Ibuprofen uses:
Mainly ibuprofen is used as an NSAID. It is also used as analgesic. It is used to treat headaches, backaches, athletic injuries, dental pain.9
1.3.2) Side effects:
Ibuprofen drug upsets stomach and causes nausea, vomiting. It also causes constipation, headache, diarrhoea, dizziness. It may cause serious liver disease. It shows some allergic reactions such as itching, rash, swelling, trouble breathing.10
Delivery of a pharmaceutical drug in to the systemic circulation, and acts on the site of action to produce its pharmacological effect, is the final effect of Drug delivery.11
Figure 3: Flow chart representation of drug delivery 12
In a biological system, different mechanisms are located to protect the system from the foreign substance while preserving nutrient uptake. The physiological arrangement and the biological and the chemical barriers associated with the structures from the first line of the unconscious defence process. If the drug delivered from any route, will almost hit and make an impact of these physiological and chemical barriers before reaching the site of action.
The gastrointestinal tract is bounded with an aqueous mucus layer which is secreted by the goblet cells.
The thickness of the intestinal mucosa varies from 100 to 150 um.
Mucus layer acts as filter for molecules having molecular mass 600-800 Daltons.
After this process it entered in to columnar epithelial cell connected together by intra cellular junctions.
These layers of the cells are composed of goblet cells, enterocytes, paneth cells.
The Epithelial layer is in vigorous contact with the lumen of the gastro intestinal tract.
The muscularis mucosa makes up the deep layer, which is thought to be interfering in contractility.
By these steps a drug can over take the intestinal mucosa through several mechanisms depends on physicochemical properties.12
The solubility and its permeability profiles are determined by its chemical structure. For the rate and extent of absorption, the concentration at the intestinal lumen and the permeation of the drug through the intestinal mucosa are responsible.
It is believed that metabolic stability and permeability of a drug molecule are two main factors in drug delivery of a drugs absorption when the solution having molecule.12
All the experiments discussed here.
2.1) Chemicals and Materials:
These chemicals and reagents are used in all over the process.
Name of the Chemicals
Sources of the Chemicals
Sigma Aldrich Chemical GMbH, Product of India.
BDH Laboratory Supplies, England. Poole prode-28304. Ec label number: 20057806.
Fisher Scientific UK Limited, Fisher: 880, code-A/3240/PB17. Batch: 0804270
Sigma Aldrich Chemistry, 99%. Cat:440104, Lot no: 92196EJ-259
Sigma Aldrich Limited. Gillingham-Dorset. SP8 4XT-UK. Lot number: 200681720
Fisher Scientific UK Limited. Code:T/2250/17, Batch: 0942848
Product of US, 97%. Code: 250540500, CAS: 1185-55-3,EC- 214-685-0, Lot: A0210064.
2.5 M HCL Solution
Fisher Scientific Limited. Batch: 0934592, Code: U/1150/P1317. S.G- 1.8 (Â¬36%)
Made in the Link Lab Laboratory. University of Greenwich, UK.
Sodium dodecyl sulphate
C12H25O4SNa, mol wt- 288.4, L-6026, SIGMA ULTRA.
Â PROD CODE: 13 70 9084, CAS : 9005-64-5,
Product of UK SIGMA ALDRICH.
Table 2 : List of chemicals
2.2) Equipments used:
Different Equipments were used to found the absorbance and Surface area. Such as
2.2.1) Ultra violet/Visible spectroscopy:
Ultra violet spectroscopy is used to find the drug uptake and drug release of the given sample. The prepared samples were examined in Shimadzu UV spectroscopy. SDS, Tween20, Ammonia are observed at 264nm.
2.2.2) Surface area:
The Surface area of silica prepared by SDS, and Tween 20 and Ammonia which are loaded by Ibuprofen drug are is determined by nitrogen adsorption using the BET method on micrometrics Gemini surface area analyser.
2.2.3) Freeze drying: 13
The freezing process contains of freezing the material. In a laboratory, this is often done by placing the material in a freeze-drying flask and rotating the flask in a bath, called a shell freezer, which is cooled by mechanical refrigeration, dry ice and liquid nitrogen. On a larger-scale, freezing is usually done using a freeze-drying machine. It is importantÂ Â to cool the material below its eutectic point, the lowest temperature at which the solid and liquid phases of the material can coexist. This ensures that sublimation rather than melting will occur in the following steps. Larger crystals are easier to freeze-dry. To produce larger crystals, the product should be frozen slowly or can be cycled up and down in temperature. This cycling process is called annealing. However, in the case of food, or objects with formerly-living cells, large ice crystals will break the cell walls. Usually, the freezing temperatures are between -50 Â°C and -80 Â°C. The freezing phase is the most critical in the whole freeze-drying process, because the product can be spoiled if badly done.
Amorphous (glassy) materials do not have an eutectic point, but do have a critical point, below which the product must be maintained to prevent melt-back or collapse during primary and secondary drying.
2.3) Synthesis of Silica:
Silica was prepared in three forms with Sodium dodecyl sulphate, Tween20 and Ammonia by following earlier articles (14, 15, 16 )
2.3.1) silica preparation with formal SDS:
Sodium Dodecyl sulphate have chemical formula C12H25NaO4S. SDS is an anionic surfactant. It is having a negatively charged sulfonate group for its "hydrophilic" end and 12- carbon chain for its "lipophilic" end
Figure 4 : Chemical structure of sodium Dodecyl Sulfate17
4 gm of sodium dodecyl sulphate was dissolved in 32 ml of distilled water. Then add 64ml of 2.5 M HCL solution and stirred to make homogenous. Add 9.4 ml of TEOS was added to the prepared solution and stirred over night for 24 hours. This Mixture of solution allow to vacuum. The collected sample is kept in desiccators for a week. After seven days, the sample is dehydrated and 1.07 gm of Hollow mesoporous silica (HMS) was suspended in 50 ml of toluene. 0.5446 mmol of Methyl-triethoxy silane was added into the HMS mixture and refluxed at 800C for 48 hours under N2 atmosphere. The obtained solid filtered and by tropic distillation with toluene. For several times HMS give wash with toluene to remove water. After washing the sample it was dried under vacuum at 600C for 2 days. Silica was prepared with SDS.
2.3.2) Silica preparation with Tween20:
Same procedure used in the 2.3.1. SDS surfactant was replaced with Tween20 surfactant. Second batch of silica is prepared.
2.3.3) Silica preparation with ammonia:Molecular Structure of Ammonia
Figure 5 : Ammonia structure18
180ml of Ethanol, 7ml of Ammonia and 50ml deionised water were added to a round bottom flask. The prepared solution is transferred into a circulating water bath which is to be pre-heated to 600C. The solution was stirred at 100 rpm all over the reaction. If the reaction reaches the temperature, the obtained mixture allowed stable for 2 hours. After which time 11 ml of TEOS was added to initiate the precipitate reaction. Further reaction left for 24 hours. To maintain the growth of silica a mixture of water and TEOS was added in the ratio of (4ml: 24ml) is added in to mixture in intervals. At the end of the reaction a white milky dispersion was formed. The reaction was terminated and the dispersion set to be cooled. The unreacted ammonia and ethanol removed by centrifugation. Finally silica was purified by dialysis in deionised water at pH 8 and kept for 3 days. 3 batches were prepared by the same method and denoted as B1, B2 and B3.
2.4) Determination of drug loading and release:
Here the detailed procedure of Drug loading and the drug Release was discussed
2.4.1) Preparation of standard solution with Ibuprofen -Na:
Standard solution of Ibuprofen sodium was prepared to compare with the prepared sample solutions. Stock solution was prepared with 40 mg/ml. 100 ml of stock solution was made. By weighing 4 gm of Ibuprofen drug dissolve in 100 ml. 1ml, 2 ml, 3 ml, 4 ml and 5 ml taken out in equal intervals from the stock solution and dilute with 100 ml water.
2.4.2) Drug Loading Method:
10 ml of Ibu-Na standard solution of concentration 40 mg/ml was added in to 0.25 gm of HMSC at room temperature. This mixture was trasferd in to vials and sealed. These vials are kept for one day. The IBU loaded drug was separated from the solution by osmosis for SDS and Tween20 samples. From prepared two samples, 1ml, 2ml, 3ml was transferred in to 100 ml volumetric flask and dilute with distilled water up to the mark. This sample analysed by UV /Visible spectroscopy at a wavelength of 264 nm by taking a small amount of solution into a cuvvet. The obtained Absorbance is compare with the calibration curve for the concentrations.
For Ammonia samples B1.B2 and B3 Loding of IBU-Na was same as the above procedure and kept for two weeks. For this samples Drug loaded samples seperated with centrifugation at 4000 rpm. From this 1ml, 2ml, 3ml was transferrd in to 100 ml volumetric flask and dilute with distilled water up to the mark. This sample analysed by UV /Visible spectroscopy at a wavelength of 264 nm by taking a small amount of solution into a cuvvet. The obtained Absorbance is compare with the calibration curve for the concentrations.
2.4.3) Drug Release Method:
Drug loaded samples were compressed in a tablet compressor with a 100 mm diameter and 0.5 mm thickness(approximetly). Drug charged tablets are allowed to soak in 100 ml of water. Temperature maintained at 310K. Sample were taken out for every 5 min with a syringe having filter paper of 0.20 m and replace after getting reading. Measure the absorbence at 264 nm using UV/Visible spectroscopy for samples SDS, Tween20, B1,B2 and B3
2.5) Charecterization method:
Silica charecterization has done only by Surface area analyser. By using liquid nitrogen sample was filled in to a sampling tube and given the data and the bonding of liquid nitrogen withsolid surface should be strong.19
Chapter - 3
RESULTS AND DISSCUSSION :
3.1) Calibration curve:
With the prepared 40 mg/ml solution different volumes of soutions took and diluted for 100ml water
So that, 1 ml of stock solution contains = (4x1/100) gm/ml
= 0.04 gm/ml of IBU-Na
2 ml contains = (4x2/100) gm/ml
=0.08 gm/ml of IBU-Na
3 ml contains = (4x3/100) gm/ml
= 0.12 gm/ml of IBU-Na
4 ml contains = (4x4/100) gm/ml
= 0.16 gm/ml of IBU-Na
5 ml contains = (4x5/100) gm/ml
= 0.20 gm/ml of IBU-Na
This 1 ml, 2 ml, 3 ml, 4 ml and 5 ml were transferred in to different 100 ml volumetric flask and dilute with water upto the mark. So each diluted standard solution contains 0.04 gm, 0.08 gm, 0.12 gm, 0.16 gm, 0.20 gm of IBU-Na
In 1 ml, standard solution contain (0.04/100) gm/ml
So, 1 lit standard solution = (0.04x1000/100) gm/lit
= 0.4 gm/lit
As 1 lit= 1000 ml, 1gm=1000 mg 20
= 0.4 mg/ml
In the same method the standard concentrations of 2ml, 3ml, 4ml, 5ml are calculated. From that the standard concentrations are 0.4 mg/ml, 0.8 mg/ml, 1.2 mg/ml, 1.6 mg/ml and 2.0 mg/ml.
For IBU-Na, 264 nm is the Î»max. By using UV/ Visible spectroscopy at 264 nm for the standard solution and calibration curve is recorded.
Absorbance (264 nm)
Table:3 Absorbance of the standard solution for different concentrations
With the above concentrations and absorbance a calibration curve is plotted with Absorbance Vs concentration
Figure 6: Calibration curve for standard Ibuprofen solution
3.2) Charecterization of Surface area analyzer:
To charecterize surface area Micromeritics Gemini surface area analyzer was used. The values of surface area are given belo
Surface area (m2/gm)
Table 4: Surface area data
Surface area of SDS,Tween20,B1,B2,B3 are found. For SDS and Tewwn20 the surface area is lessthan 1 and for Ammonia it is 26.1 m2/gm, compartivly better than SDS and Tween20. This is because due to moisture contains in the surfactents and stuck to the silica samples and gave poor surface area. Further samples dried for overnight even no change in result.
3.3) Storage of Ibuprofen in the prepared silica:
Load Ibuprofen drug in to prepared silica as per the method 2.4.2. Absorbence is measured by UV/visible spectroscopy at 264 nm and absorbence of the samples as follows:
Absorbence (264 nm)
Table 5: Absorbence values of SDS and Tween20
For Ammonia samples the same procedure 2.4.2 is follwed and absorbence is measured by UV/Visible spectroscopy at 264 nm. The absorbence of Ammonia samples as follows
Absorbence (264 nm)
Table 6: Absorbance of Ammonia samples
By using this Absorbance value for different batches, concentrations of the samples in differen volumes are known by comparing the calbration curve (Figure-6)
Standard Graph (mg/ml)
Table 7: Concentrations of the samples by comparing calibration curve
With these concentrations actual concentrations is to be measure by following method:
M1= New concentrations of IBU sodium
V1=1ml, 2ml, 3ml of concentration solute
M2= Concentration read of graph for 1ml solute
V2= 100ml diluted volume
For SDS the actual concentrations at different volumes:
For 1 ml: M1V1 = M2V2
Then M1 X 1 = 0.41 X 100
M1 = (0.41 X 100)/ 1
M1 = 41 mg.
For 2 ml: M1V1 = M2V2
Then M1 X 2 = 0.77 X 100
M1 = (0.77 X 100)/ 2
M1 = 38.5 mg.
For 3 ml: M1V1 = M2V2
Then M1 X 3 = 1.15 X 100
M1 = (1.15 X 100)/ 3
M1 = 38.33 mg.
Like the above calculations Tween20, B1, B2 and B3 are calculated in the same method. By this actual concentrations of different volumes standard deviation was calculated
By these actual concentrations of the samples standard deviation was calculated for
Sum of (A- Ä€)2 = 4.17
Table 8: Standard deviation data of SDS
Standard deviation, SD = âˆš (A-Ä€)2 / N-1 21
N = Number of batches
Standard deviation, SD = âˆš 4.17 / 3-1
= âˆš 2.085
= 1.44 mg/ml
Initial IBU-Na added, M Initial = (40x10) mg
= 400 mg
New concentration of IBU-Na, C New = 39.28 mg/ml
So, New amount of IBU-Na, M New = (C New Ã- 10) mg
= (39.28 Ã- 10) mg
= 392.8 mg
Mass of IBU-Na adsorbed by 50 mg if silica = (M Initial - M New)
= (400 - 392.8)
= 7.2 mg
Amount of IBU-Na adsorbed per gram of silica = (M Initial - M New) Ã- (1000/50)
= 7.2 Ã- 20
= 14.4 mg
IBU-Na loaded per gram in SDS Silica = 14.4 mg
Sum of (A- Ä€)2 = 12.703 Table 9: Standard deviation data of Tween20
Standard deviation and mass of the drug present in Tween20 is calculated in the method of SDS.
According to the calculation, standard deviation of Tween20 is 2.42 mg/ml and mass of drug in silica is 334 mg
Sum of (A- Ä€)2 = 1.412
Table 10: Standard deviation data of B1
Standard deviation and mass of the drug present in B1 is calculated in the method of SDS.
According to the calculations, Standard deviation of the B1 sample is 0.840 mg/ml and mass of drug in Silica is 378 mg
Sum of (A- Ä€)2 = 4.67
Table 11: Standard deviation data of B2
Standard deviation and mass of the drug present in B2 is calculated in the method of SDS.
According to the calculations, Standard deviation of B2 sample is 1.52 mg/ml and Mass of the drug present in silica was 668 mg.
Sum of (A- Ä€)2 = 14.02 Table 12: Standard deviation data of B3
Standard deviation and mass of the drug present in B3 is calculated in the method of SDS.
According to calculations, standard deviation of B3 sample is 2.648 mg/ml and mass of drug present in the silica sample was 212 mg.
From the average of this B1, B2, B3 samples, found the IBU-Na present in the whole Ammonia solution.
Sum of (A- Ä€)2 = 2.66
Table 13: Standard deviation of data of Ammonia
Standard deviation and mass of the drug present in whole ammonia is calculated in the method used in SDS.
According to calculations, standard deviation of Ammonia sample is 1.15 mg/ml and mass of drug present in the silica sample was 418 mg.
In the below table all the mean, standard deviation and amount of IBU-Na in different prepared silica was determined.
Mean of amount of IBU-Na in solution
Standard deviation in solution
Amount of IBU-Na adsorbed /gm in SiO2 (mg/ml)
In whole ammonia
Table: 14 Amount of IBU-Na in different prepared silica
From this above table the Drug loaded in each silica sample was given. In SDS it contains 144 mg/gm. In Tween20 contains 334 mg/gm. In B1 it contains 378 mg/gm. In B2 it contains 668 mg/gm. In B3 it contains 212 mg/gm. In the whole Ammonia solution it contains 418 mg/gm of IBU-Na.
It seems that less amount of IBU-Na was reacted with SDS. Comparatively with all the samples B2 having more drug uptake. As the standard formula Absorbance is directly proportional to Concentration, Tween20 and B2 will have high Absorbance.
3.4) Drug release from Mesoporous silica:
Table 15: Drug Release Patron for different batches of silica
By the table it is easy to find Ammonia samples having good drug absorbance and Tween20 having good drug release.
By the above following data drug release graphs were prepared with Absorbance vs time.
Figure 7: Drug release graph for tween20
Figure 8: Drug release graph for SDS
Figure 9: Drug release graph for B1
Figure 10: Drug release graph B2
Figure 11: Drug release graph of B3
Individual drug release graphs for SDS, Tween20, B1, B2, B3. These graphs show good release of drug from all silica batches. SDS has good absorbance than Tween20. By Absorbance is directly proportional to concentration so SDS having more drug in it and shows fast absorbance. In the comparison of B1, B2, B3 these shows more good absorbance as soon as tablet placed in dissolution medium it started release of drug and at 20-30 min.
From the above individual drug release profile a comparison of drug release is plotted in the below graph.
Figure 12: Comparison of drug release for all batches
3.5) 'T' Value :
For all the drug release samples a specific time was found. The time is denoted as't'. The't' values of the different silica batches are:
Table 16:'t' values for all batches
From Table 13 it denote't' values of different batches of silica. It conveys SDS and tween20 having slow't' value (40-45) and also having surface area <1. For other batches like B1, B2, B3 the't' value shows fast at (20-30) having surface area (26 m2/gm). By this 't' value data it is clear that the high surface area having samples are showing good't' value. By poor pore size and structure of the sample't' value was affected. The hydrogen and IBU-Na having strong bond this may delay drug release.
4. Conclusion and Future Recommendations:
Mesoporous silica was prepared in different batches with different surfactants such as SDS and Tween20. Silica also prepared with Ammonia with 3 batches in the name of B1, B2, B3. By using Ibuprofen-Na as the drug, drug loaded in to silica in one step process and drug is loaded successfully and allowed to characterise with surface area analyser. It shows low surface area for the surfactants i.e <1 and for other 3 batches B1, B2, B3 the surface area is better i.e 26 m2/gm and also IBU-Na having sodium salt and ammonia is having alkaline properties. So it shows the good absorbance for the silica prepared with ammonia. The main goal of this project is to synthesize the prepared mesoporous silica containing good surface area. Though the surface area is poor for all samples the drug uptake and release of the sample shows positive. This poor surface area is due to some affecting factors like pH, temperature, drying of the sample etc. This project shows silica shows more effectively in the drug delivery.
4.2 Future Recommendations:
According to the result from drug uptake and drug release of IBU-Na shows successful result but some results dint show good results for drug release and drug uptake like:
The poor surface area of the silica dint shows the better absorbance and uptake as desired. If the sample has dried for some more time it may give better result.
In dilutions of samples for B1, B2, B3 there is some manual problems so that different concentrations for each sample.
Good values may obtain if change temperature, Mixing time, standby time, pH and the percentage of chemicals.
It is better to use the calibrated equipments such as weighing balance, UV apparatus, and all the equipments used. This will also shows some wrong results and weights.
There is less time to do this uptake and release of drug so that it gave some poor results than expected.
Further investigation should be done on the bond strength of silica and the drug IBU-Na. The pellet prepared due to some problems like more pressure or wet sample no formation of good pellets. For that some investigation should be done
In the further process the works should be done carefully then better results may appear.