CHAPTER 3 3.0 Introduction As per Sir Arthur Conan Doyle, It is a capital mistake to theorize before one has data. Preformulation work is the foundation for development of any robust formulations (G. Banker et al., 2000). Preformulation is defined as a stage of development during which the physicochemical properties of drug substance are characterized (L.J. Ravin et al, 1990). Almost all drugs are marketed as tablets, capsules or both. Prior to the development of these major dosage forms, it is essential that to pertain fundamental, physical and chemical properties of the drug molecule and other essential properties of the drug powder are determined. This information decides many of the subsequent events and approaches in formation development (H. Brittain et al, 1995; E.F. Fiese et al. 1986). Preformulation involves the application of biopharmaceutical principles to the physicochemical parameters of drug substance to characterize the designing of optimum drug delivery system. Prior to the development of any dosage form new drug, it is essential that certain fundamental physical & chemical properties such as characterization, solubility, melting point, compatibility etc of drug powder and formulation are determined. This information may dictate many of subsequent event & approaches in formulation development. The wrong approach of Preformulation could affect drug performance and development of an efficacious dosage form. The aim of this section was to investigate a robust prototype formulation of rapid dispersible tablets. The Preformulation of formulation is investigated by using characterization of active, and drug excipients compatibility study. Characterization of active Drug Excipients compatibility On the basis of current objective, the Preformulation study was designed as, 1. Characterization of Actives such as Tolfenamic Acid and Paracetamol 2. Drug excipients compatibility study of Rapid Dispersible Tablets of Paracetamol JJT University Page 30
3. Drug excipients compatibility study of Rapid Dispersible Tablets of Tolfenamic Acid 4. Drug excipients compatibility study for Fixed Dose Combination of Tolfenamic Acid and Paracetamol 3.1 Materials and Equipments 3.1.1 Materials List of raw materials used in formulation of rapid dispersible tablets is summarized in Table 3.1. Table 3.1: List of Materials Used in Formulation and Development Excipients Grade Manufacturer Tolfenamic Acid BP Elder Pharma. Paracetamol IP/BP Ankur Drugs Lactose Monohydrate IP DMV Fonterra Microcrystalline Cellulose IP Sigachi Mannitol IP Roquette β-cyclodextrin (Betadex) BP Emcure Pharma Polyethylene Glycol IP Elder Pharma Hypromellose USP Shin-Etsu Chemicals Eudragit EPO USP Evonik Industries Urea IP Cadila Pharma Povidone (PVP K-30) IP FMC Biopolymer Croscarmellose sodium (Ac-Di-Sol TM ) IP FMC Biopolymer Crospovidone (Kollidon CL TM ) IP BASF Limited Sodium Starch Glycolate Type A(Explotab TM ) IP Cadila Pharma Polacrillin Potassium (Kyron T-314 TM ) USNF Corel Pharma Chem Sodium Lauryl Sulfate IP Parchem Magnesium Stearate IP Pharma Trans Purified Talc IP Elder Pharma Aspartame IP Elder Pharma Flavor Vanilla IH Flavors International JJT University Page 31
Flavor Strawberry IH Flavors International Ethanol and Methanol IH Shree Chemicals 3.1.2 Equipments List of manufacturing and analytical equipments used in formulation development of rapid dispersible tablets is summarized in Table 3.2. Table 3.2: List of Equipments Used in the Formulation Development. Name of the Equipment Manufacturer Electronic weighing balance Sartorius Rapid Mixer Granulator (H.S.M.G 10) Kevin Machinery Air jet Mill Shree Engg. 16 Station compression machine Cadmach Machinery Co. Pvt. Ltd Hardness tester Erweka Digital Vernier Calipers Mitutoyo, Japan Friability Apparatus Electrolab Disintegration time tester Electrolab Moisture analyzer Sartorius Bin Blender Solace Engg. Vacuum tray dryer Shree Engg. Fluid Bed Processor Pam Glatt Tap density tester Electro lab Electromagnetic sieve shaker Electrolab (USP) Oscillating granulator Frewitt Mechanical stirrer Remi Electronics, India Dissolution Equipment Electrolab Fourier Transform Infrared Spectroscopy Shimadzu U V Spectroscopy Shimadzu High Performance Liquid Chromatography Shimadzu JJT University Page 32
Equipment Melting point apparatus Veego 3.2 Characterization of API (British Pharmacopoeia, 2010) 3.2.1 Physical Appearance Physical appearance of Tolfenamic Acid is white or slightly yellow, crystalline powder (British Pharmacopoeia, 2010). Physical appearance of Paracetamol is white or almost white crystalline powder (British Pharmacopoeia, 2010). A small sample of API was taken for the visual observation. 3.2.2 Melting Point Confirmation of melting point for the actives was determined by open capillary method. The capillary tube with opens from one side was filled with active by repeated tapping to fill a sufficient amount of drug. The melting point was measured by using digital melting point apparatus. The temperature at which the drug started melting was recorded. The triplicate reading was recorded by repeating the same procedure. The melting point of active was compared with the reported melting point of actives as per British Pharmacopoeia. 3.2.3 Infra-red (FTIR) Analysis The identification of actives was also confirmed by using Infra-red analysis of drug sample. The FTIR spectra were obtained using FTIR spectrometer (FTIR 8001, Shimadzu). The Drug sample were previously triturated and mixed thoroughly with potassium bromide in 1:5 (Sample: KBr) ratio, KBr discs were prepared by compressing the powders at a pressure of 5 tons for 5 min in hydraulic press (Sushma Talegaonkar et. Al, 2007). Scans were obtained at a resolution of 2 cm 1 from 4500 to 400 cm. It was carried out to check for functional groups of drug. The spectrum was than compared with standard spectrum of actives as per the British Pharmacopoeia. 3.2.4 U V Spectrophotometer JJT University Page 33
The identification of actives was characterized by using UV spectrophotometry. The method is adopted from British Pharmacopoeia. Tolfenamic Acid 20 mg of Tolfenamic acid was dissolved in a mixture of 1 volume of 1 M hydrochloric acid and 99 volumes of methanol R and dilute to 100 ml with the same mixture of solvents. 5.0 ml of above solution was again diluted to 50 ml with a mixture of 1 volume of 1 M hydrochloric acid and 99 volumes of methanol R. The diluted solution than examined between 250 nm and 380 nm, the solution shows 2 absorption maxima, at 286 nm and 345 nm. The ratio of the absorbance measured at the maximum at 286 nm to that measured at the maximum at 345 nm is 1.2 to 1.4. Paracetamol Take 50 mg of sample and dissolve in small quantity of methanol R and make the volume up to 100 ml. Take 2.0 ml of solution to 0.5 ml of a 10.3 g/lt solution of hydrochloric acid R and dilute to 100.0 ml with methanol R. Immediately measure the absorbance of test solution at the absorption maximum at 249 nm. The specific absorbance at the maximum is 860 to 980. 3.3 Drug Excipients Compatibility Study For the development of rapid dispersible tablet formulation, the pharmaceutical development was initiated with drug-excipients compatibility study. The Preformulation study was conducted to formulate two types of formulation. Earlier formulation is formulation of Rapid dispersible tablets of Tolfenamic acid, and Paracetamol while later is combination of Tolfenamic acid and paracetamol. The selection of excipients for all the formulation was based on reference innovators and various literature searches of respective formulations. The Preformulation details of remaining formulation and drug excipients study was summarized in Table 3.3. JJT University Page 34
Table 3.3: Preformulation Details of Drugs and Excipients Drug + Excipients Drug Excipients Ratio Tolfenamic Acid 1 gms Paracetamol 1 gms TA + Mannitol 1:1 TA + Microcrystalline Cellulose 1:1 TA + Sodium Lauryl Sulfate 1:1 TA + PVP K-30 1:1 TA + Polacrillin Potassium 1:1 TA + Croscarmellose Sodium 1:1 TA + Crospovidone 1:1 TA + Sodium Starch Glycolate 1:1 TA +Magnesium Stearate 1:1 TA + Aspartame 10:1 TA + Vanilla Flavor 10:1 TA + Strawberry Flavor 10:1 PA + Mannitol 1:1 PA + Microcrystalline Cellulose 1:1 PA + β-cyclodextrin 1:1 PA+ Urea 1:1 PA+ Lactose Monohydrate 1:1 PA + Sodium Lauryl Sulfate 1:1 PA + PVP K-30 1:1 PA + Polacrillin Potassium 1:1 PA + Croscarmellose Sodium 1:1 PA + Crospovidone 1:1 PA + Sodium Starch Glycolate 1:1 PA +Magnesium Stearate 1:1 PA + Aspartame 10:1 JJT University Page 35
PA + Vanilla Flavor 10:1 Pa+ Strawberry Flavor 10:1 TA + PA + Mannitol 1:1:1 TA + PA + Microcrystalline Cellulose 1:1:1 TA + PA + β-cyclodextrin 1:1:1 TA + PA+ Urea 1:1:1 TA + PA+ Lactose Monohydrate 1:1:1 TA + PA + Sodium Lauryl Sulfate 1:1:1 TA + PA + PVP K-30 1:1:1 TA + PA + Polacrillin Potassium 1:1:1 TA + PA + Croscarmellose Sodium 1:1:1 TA + PA + Crospovidone 1:1:1 TA + PA + Sodium Starch Glycolate 1:1:1 TA + PA +Magnesium Stearate 1:1:1 TA + PA + Aspartame 10:10:1 TA + PA + Vanilla Flavor 10:10:1 TA + Pa+ Strawberry Flavor 10:10:1 Blend of TA with all excipients of TA mentioned for individual study to make prototype formulation for Rapid dispersible tablets of Tolfenamic Acid Blend of PA with all excipients of PA mentioned for individual study to make prototype formulation for Rapid dispersible tablets of Paracetamol Blend of TA + PA with all excipients of TA + PA mentioned for individual study to make prototype formulation for fixed dose combination Approx 5 gms Approx 5 gms Approx 5 gms 3.3.1 Physical Observation Physical observation such as color, texture, and appearance during Preformulation study were evaluated for initial and after 15, 30 days interval as per the scheme of drug excipients compatibility. The scheme for Drug substance-excipients Compatibility study is tabulated in the Table 3.4. JJT University Page 36
Table 3.4: Scheme for Drugs - Excipients Compatibility Studies Sr. No. Condition Time -point Type of packing 1 Initial Zero day Glass vial 2 Stress Condition 50 0 C Up to 15 days Glass vial 3 40 0 C/ 75% RH Up to 30 days Glass vial 3.3.2 Analytical Observation by Spectrophotometric Evaluation The drug excipients compatibility study also confirmed with spectrophotometric evaluation. The comparative evaluation of spectrophotometric spectrum for active such as Tolfenamic Acid, Paracetamol, blend of Tolfenamic Acid, blend of Paracetamol at initial stage of Preformulation and after completetion of Preformulation studies were investigated for any degradation. The FTIR spectra were obtained using FTIR spectrometer (FTIR 8001, Shimadzu). The samples were previously triturated and mixed thoroughly with potassium bromide in 1:5 (sample: KBr) ratio, KBr discs were prepared by compressing the powders at a pressure of 5 tons for 5 min in hydraulic press. Scans were obtained at a resolution of 2 cm -1 from 4500 to 400 cm-1. 3.4 Result and Discussion 3.4.1 Characterization of API (British Pharmacopoeia, 2010; Handbook of Pharma. Excipients, 2009) 3.4.1.1 Physical Appearance The physical appearance of Tolfenamic Acid and Paracetamol was compared as per the specification of British Pharmacopoeia 2010 and it complies as per the standard description of actives. The observation of description is summarized in Table 3.5. JJT University Page 37
Table 3.5: Physical Observation of Tolfenamic Acid and Paracetamol Name of Active Tolfenamic Acid Paracetamol Description as per British Pharmacopoeia, 2010 white or slightly yellow, crystalline powder white or almost white crystalline powder Complies Complies Observation 3.4.1.2 Melting Point The average melting point of Tolfenamic acid and Paracetamol by using digital melting point apparatus is tabulated in table. The melting point of active (Table 3.6) is confirmed as per the standard value given in the British pharmacopoeia 2010. Table 3.6: Determination of Melting Point of Tolfenamic Acid and Paracetamol (mean ± S.D, n = 6) Description Standard Melting Point (BP, 2010) Observation Tolfenamic Acid About 213 C 212.5 ± 0.3 0 C Paracetamol 168 C to 172 C 170.2± 0.25 0 C 3.4.1.3 Infra-red (FTIR) Analysis The identification of Tolfenamic acid and Paracetamol was confirmed by using Infra-red analysis of drug sample, the spectra of standard reference (British Pharmacopoeia, 2010) and taste reference (sample of Tolfenamic acid and Paracetamol) are presented in Graph 3.1 to 3.6. On the basis of comparison of spectrum the taste spectrum is confirmed as Tolfenamic acid and Paracetamol. JJT University Page 38
A. Infra-red (FTIR) Analysis - Paracetamol Graph 3.1: IR Spectra of Paracetamol (Test Sample) Graph 3.2: IR Spectra of Paracetamol (Reference Sample - WS) JJT University Page 39
Graph 3.3: Comparative IR Spectra of Paracetamol (Test vs. Reference) B. Infra-red (FTIR) Analysis Tolfenamic Acid Graph 3.4: IR Spectra of Tolfenamic Acid (Test Sample) JJT University Page 40
Graph 3.5: IR Spectra of Tolfenamic Acid (Reference Sample) Graph 3.6: Comparative IR Spectra of Tolfenamic Acid (Test vs. Reference) JJT University Page 41
3.4.1.4 U V Spectrophotometer A - Determination of λmax Paracetamol λmax of Paracetamol was observed at 249 nm which was then chosen as wavelength for detection of drug. Graph 3.7: UV Spectrum of Paracetamol Table 3.7: Observation for Calibration Curve of Paracetamol Con µg/ml Abs in nm 0.0060 0.540 0.0080 0.735 0.0100 0.890 0.0120 1.061 0.0140 1.249 JJT University Page 42
Graph 3.8: Calibration Curve of Paracetamol B - Determination of λmax Tolfenamic Acid λmax of Tolfenamic Acid was observed at 286 nm which was then chosen as wavelength for detection of drug. Graph 3.9: UV spectrum of Tolfenamic Acid JJT University Page 43
Table 3.8: Observation for Calibration Curve of Tolfenamic Acid Con µg/ml Abs in nm 2.5 0.134 5.0 0.242 7.5 0.366 10.00 0.483 12.50 0.622 15.00 0.753 17.50 0.854 1 0.9 0.8 0.7 0.6 0.5 0.4 0.3 y = 0.049x + 0.002 R² = 0.998 Series1 Linear (Series1) Linear (Series1) 0.2 0.1 0 0 5 10 15 20 Graph 3.10: Calibration curve of Tolfenamic Acid Conclusion On the basis of characterization of API, the Tolfenamic Acid and Paracetamol comply as per the given specification active in British Pharmacopoeia, 2010. JJT University Page 44
3.4.2 Drug Excipients Compatibility Study 3.4.2.1 Physical Observation Physical observation such as color, texture, and appearance and any significant changes during Preformulation study were evaluated for initial and after 15, 30 days interval. On the basis of stress study at 50 0 C for 15 days and accelerated condition at 40 0 C 75% RH for 30 days, there was no any significant changes observed in Preformulation study. So the selection of excipients does not have any physical effect on stability. The observation of Preformulation is also summarized in Table 3.9. Drug + Excipients Table 3.9: Preformulation details of drug excipients Initial Observation Physical Appearance 15 days 50 0 C 30 days 40 0 C 75% RH Tolfenamic Acid off white colored powder NC NC Paracetamol off white colored powder NC NC TA + Mannitol off white colored powder NC NC TA + MCC off white colored powder NC NC TA + SLS off white colored powder NC NC TA + PVP K-30 off white colored powder NC NC TA + Polacrillin Potassium off white colored powder NC NC TA + CCS off white colored powder NC NC TA + Crospovidone off white colored powder NC NC TA + SSG off white colored powder NC NC TA +Magnesium Stearate off white colored powder NC NC TA + Aspartame off white colored powder NC NC TA + Vanilla Flavor Sweet off white colored powder NC NC TA + Strawberry Flavor Flavored off white colored powder NC NC PA + Mannitol Flavored off white colored powder NC NC PA + MCC off white colored powder NC NC JJT University Page 45
PA + β-cyclodextrin off white colored powder NC NC PA+ Urea off white colored powder NC NC PA+ Lactose Monohydrate off white colored powder NC NC PA + SLS off white colored powder NC NC PA + PVP K-30 off white colored powder NC NC PA + Polacrillin Potassium off white colored powder NC NC PA + CCS off white colored powder NC NC PA + Crospovidone off white colored powder NC NC PA + SSG off white colored powder NC NC PA +Magnesium Stearate Sweet off white colored powder NC NC PA + Aspartame Sweet off white colored powder NC NC PA + Vanilla Flavor Flavored off white colored powder NC NC Pa+ Strawberry Flavor Sweet flavored off white colored Powder NC NC TA + PA + Mannitol Flavored off white colored powder NC NC TA + PA + MCC off white colored powder NC NC TA + PA + β-cyclodextrin off white colored powder NC TA + PA+ Urea off white colored powder NC TA + PA+ Lactose Monohydrate off white colored powder NC NC TA + PA + SLS NC NC off white colored powder NC NC TA + PA + PVP K-30 off white colored powder NC TA + PA + Polacrillin Potassium off white colored powder NC NC TA + PA + CCS off white colored powder NC NC TA + PA + Crospovidone off white colored powder NC NC TA + PA + SSG off white colored powder NC NC TA + PA +Magnesium Stearate NC Sweet off white colored powder NC NC JJT University Page 46
TA + PA + Aspartame TA + PA + Vanilla Flavor TA + Pa+ Strawberry Flavor Sweet off white colored powder NC NC Flavored off white colored powder NC NC Sweet flavored off white colored Powder NC NC Blend of TA with all excipients of TA mentioned for individual study to make prototype formulation for Rapid dispersible tablets of Tolfenamic Acid Blend of PA with all excipients of PA mentioned for individual study to make prototype formulation for Rapid dispersible tablets of Paracetamol Blend of TA + PA with all excipients of TA + PA mentioned for individual study to make prototype formulation for fixed dose combination NC No Change Sweet flavored off white colored Powder Sweet flavored off white colored Powder Sweet flavored off white colored Powder NC NC NC NC NC NC 3.4.2.2 Analytical Observation by Spectrophotometric Evaluation The drug excipients compatibility study is also confirmed with spectrophotometric evaluation. The comparative spectrophotometric spectrum for initial blend and after completetion of Preformulation studies is presented in the respective Graph 3.11 3.14. Their results indicate that there is no chemical incompatibility between drug and excipients used in the formulation of rapid dispersible tablets. JJT University Page 47
Graph 3.11: IR Spectrum of Blend of TA (TA#FA) with all excipients of TA for Rapid dispersible tablets of Tolfenamic Acid at initial stage of Preformulation study Graph 3.12 IR Spectrum of Blend of PA with all excipients of PA for Rapid dispersible tablets of Paracetamol at initial stage of Preformulation study JJT University Page 48
Graph 3.13: IR Spectrum of Blend of TA (TA#FB) with all excipients of TA for Rapid dispersible tablets of Tolfenamic Acid at final stage of Preformulation study Graph 3.14: IR Spectrum of Blend of PA with all excipients of PA for Rapid dispersible tablets of Paracetamol at Final stage of Preformulation study. JJT University Page 49
3.5 Conclusion The selection of excipients used in formulation of dispersible tablets was based on the available literature and database of innovator products. Preformulation study was completed to reinsure the compatibility of drug with excipients. On the basis of physical evaluation such as stress study, accelerated studies, there was no significant effect observed on the appearance of blend. From the Drug: excipients compatibility it was found that the selected excipients were found to be compatible with the Active Pharmaceutical Ingredient at the different stability conditions that is 50 C ± 2 C(Stress Condition) for 15 days, 40 0 C ± 2 C I 75%RH ± 5%Rh for 1 month. So the excipients selection for the proposed formulation is most suitable for the proposed formulation of Rapid dispersible formulation of Tolfenamic Acid and combination of Paracetamol and Tolfenamic acid. The spectrophotometric evaluation of drug with excipients also performed to confirm the effect of temperature and humidity, and degradation of active during preformulation studies. There was no significant variation observed on the profile of active on the basis of comparative FTIR spectrum of drug excipients during preformulation study. The characterization of active of Tolfenamic acid and Paracetamol also complies as per the given specifications of British Pharmacopoeia. JJT University Page 50