1. INTRODUCTION:
Infrared spectroscopy is one of most powerful analytical technique which offers the possibility of chemical identification. This technique when coupled with intensity measurements which might be used quantitative determination. In valuable importance is that it provides useful information structure of molecule without some method evaluation. IR spectroscopy can solve many problems in organic chemistry1
Figure 1: Chemical structure of Cetirizine Hydrochloride
Figure 2: Chemical structure of Phenylephrine Hydrochloride
Cetirizine hydrochloride, 2-[2-[4-[(4chlorophenyl)-phenyl methyl] piperazin-1-yl]ethoxy]acetic acid, this drug is a selective peripheral H1 receptor antagonist. Thus it inhibits the allergic symptoms produced by histamines like cold, rhinorrhea, sneezing, urticaria etc. The drug has some mast cell stabilizing properties. It also inhibit exotoxin-induced eosinophil TEM through both dermal and lung micro vascular endothelial cells. So inhibit eosinophil chemo taxis and also inflammation caused by it.
Phenylephrine hydrochloride, (R)-1-(3-hydroxyphenyl)-2-methylaminoethanol hydrochloride, The drug exerts it`s pharmacological action by acting as a selective alpha-1 adrenergic agonist. It causes vasoconstriction and increases total peripheral resistance and raises blood pressure. It reduces intraocular tension by constricting ciliary body blood vessels and produce mydriasis (without cycloplegia). It exerts nasal decongestant action; by vasoconstrictory action on arterioles of nasal mucosa. It prolongs and localizes the action of anaesthetics due to it’s vasoconstrictory action on skin, mucous membrane and viscera and thus slows the rate of absorption of local anaesthetics.
Various analytical methods for estimation of single drug cetirizine hydrochloride and phenylephrine hydrochloride in bluk as well as pharmaceuticals including HPLC, UV–visible are reported2-10
To the best of our knowledge, there is no literature data published on combined dosage form of cetirizine hydrochloride and phenylephrine hydrochloride for their estimation. The aim of the proposed method is to develop and validate a FT-IR method for estimation of cetirizine hydrochloride and phenylephrine hydrochloride in their pharmaceutical formulation.
2. MATERIALS AND METHODS:
2.1. Chemical and Reagents. Standard sample of cetirizine hydrochloride and phenylephrine hydrochloride were obtained as gift sample from Bidwai chemicals Pvt. Ltd, Nanded. Alerid-D (cetirizine hydrochloride 5mg and phenylephrine hydrochloride 10mg) is available from local market. Pure drug KBr analytical grade was used as diluent.
2.2. FTIR Instrumentation. FT-IR spectrophotometer (IR-Affinity-1, Shimadzu Corp., Japan) equipped with diffuse reflectance sampling interface and attached with computer operated Shimadzu IR solution software was used for collection and analyze the data. It also equipped with detector- DLATGS and uses a high-energy long life ceramic light source. FT-IR spectrum was recorded in range of 4000-400 cm-1 with 45 scans and resolution of 8 cm-1. Analytical weighing balance: A named; Model AA-2200. [Max. 200g, Min. 0.01g; e=0.0001g]
2.3. Calibration curve. The calibration curve were prepared with six different concentrations of cetirizine hydrochloride in the range 0.2-1.2% w/w and for phenylephrine hydrochloride in the range 0.4-2.4% w/w. Appropriate quantity of both drugs were diluted with KBr to get around 1000 mg and triturated to ensure sample homogeneity.
2.4. Method validation. The developed method was validated for precision, accuracy and linearity.
2.4.1. Precision .The precision method was carried out by repeatability and intermediate precision studies. The repeatability study is carried out by six different concentrations of cetirizine hydrochloride and phenylephrine hydrochloride in the range of 0.2-1.2%w/w and 0.4-2.4%w/w respectively on same day (day1) and intermediate precision study is carried out by repeating studies( on day 3).
2.4.2. Accuracy. The accuracy study was carried out by standard addition method with recovery of pure drug from excipients at three different quantities (80,100 and 120% w/w). To the pre analyzed Alerid-D tablet powder known amount of cetirizine hydrochloride and phenylephrine hydrochloride standard powder corresponding to 80,100 and 120% of label claim was added. The sample was mixed thoroughly and analysed by making appropriate 0.2% w/w and 0.4 %w/w dilution with KBr powder in six replicates.
2.4.3. Linearity. The linearity of calibration curve is assessed by linear regression. The samples were prepared in the concentrations of 0.5-3.0% w/w and 1.0-6.0%w/w for cetirizine hydrochloride and phenylephrine hydrochloride respectively. The linearity of the both drugs is carried out in the range of 0.2-1.2%w/w and 0.4-2.4%w/w for cetirizine hydrochloride and phenylephrine hydrochloride respectively.
2.5. Analysis of marketed formulation. Alerid-D tablet (cetirizine hydrochloride 5mg and phenylephrine hydrochloride10mg) tablet were used to determine the drug content. Twenty tablets were weighed accurately, their average weight determined, and finely powdered. Tablet powder is diluted with KBr to get 1000 mg sample containing approximately 0.2% w/w and 0.4 %w/w of cetirizine hydrochloride and phenylephrine hydrochloride respectively. The analysis is carried out using six different concentrations of both drugs.
2.6. Force degradation studies:
Force degradation studies were performed on CET and PHE to prove the stability indicating property of the method. The stress conditions applied for degradation study involved thermal, photolytic and sunlight degradation.
2.6.1. Thermal degradation:
Thermal degradation was carried out by exposing pure drugs to dry heat at 80ºC. Samples were withdrawn at interval of 6hr. The samples after exposure to heat were diluted or mixed with KBr to get CET (0.2 % w/w) and PHE (0.4 % w/w). Wave number was measured at 1741 cm-1 and 3419 cm-1 for CET and PHE, respectively. Finally peak intensity of sample was compared with standard peak intensity and percent degradation and percent assay was calculated. FT IR spectra of thermal degradation are shown in figure 8 and 9 respectively.
2.6.2. Photolytic degradation:
Pure drugs were exposed to UV radiations and samples were withdrawn at interval of 6hr. The samples after exposure to light diluted with KBr to get CET (0.2 % w/w) and PHE (0.4 % w/w). Wave number was measured at 1741cm-1 and 3419 cm-1 for CET and PHE respectively. Finally peak intensity of sample was compared with standard peak intensity and percent degradation and percent assay was calculated. FT IR spectra of photolytic degradation are shown in figure 10 and 11respectively.
2.6.3. Sunlight Degradation:
Sunlight degradation is performed by exposing the pure drugs to sunlight in open space. Samples are withdrawn at interval of 6hr. The samples after exposure to sunlight were diluted or mixed with KBr to get CET (0.2% w/w) and PHE (0.4 % w/w). Wave number was measured at 1741cm-1 and 3419 cm-1 for CET and PHE respectively. Finally peak intensity of sample was compared with standard peak intensity and percent degradation and percent assay was calculated. FT IR spectra of photolytic degradation are shown in figure 12 and 13 respectively.
Figure 3: Overlay of linearity spectra of Cetirizine hydrochloride of concentration range (0.2-1.2 % w/w)
Figure 4: Overlay of linearity spectra of phenylephrine hydrochloride of concentration range (0.4-2.4%w/w)
3. RESULT AND DISCUSSION:
The FTIR spectrum for pure sample of cetirizine hydrochloride and phenylephrine hydrochloride shows absorbance bands in the range of 1741 cm-1 and 3419cm-1. The low intensity absorbance bands arising from cetirizine hydrochloride and phenylephrine hydrochloride were not much affected by dilution in dry potassium bromide; therefore, in the present study we have used dry potassium bromide as a diluent. The most prominent absorbance band corresponding to the carbonyl group centered in the range of 1741 cm-1 for diluted samples of cetirizine hydrochloride and hydroxyl group in the range of 3419cm-1 for diluted samples of phenylephrine hydrochloride in dry potassium bromide was within the 2.0 absorbance units. The overlay spectra of cetirizine hydrochloride and phenylephrine hydrochloride of various concentrations are shown in figure 3 and figure 4.
Table1: Linear regression data for cetirizine hydrochloride and phenylephrine hydrochloride
|
Parameters |
CET |
PHE |
|
Wave number (cm-1) |
1741 |
3419 |
|
Linearity range (% w/w) |
0.2-1.2 |
0.4-2.4% |
|
Limit of detection (% w/w) |
0.373 |
0.655 |
|
Limit of quantitation (% w/w) |
1.13 |
1.986 |
|
Y=c+mx |
0.5033+0.0532x |
0.3479+0.0302x |
|
Slope |
0.0532 |
0.0302 |
|
Intercept |
0.5033 |
0.3479 |
|
Regression coefficient (r2) |
0.9974 |
0.998 |
Calibration curve is described by the equation 𝑦=mx+cwhere𝑦 represents peak area and x represents concentration of cetirizine hydrochloride and phenylephrine hydrochloride. Initially the samples in the concentration range of 0.5–3.0% w/w and 1.0-6.0 were analyzed to determine the linearity. The calibration curve with good linearity was established ranging from 0.2 to 1.2% w/w cetirizine hydrochloride and 0.4-2.4%w/w phenylephrine hydrochloride in potassium bromide. The corresponding linear regression equation was 𝑦=0.0532x+0.5033 and 0.0302x+0.3479 for cetirizine hydrochloride and phenylephrine hydrochloride and the correlation coefficient for calibration curve was 0.997 and 0.998 respectively. (Table 1, Figure 5 and 6).