Analytical Review on Escitalopram oxalate and their combinations in Bulk and Pharmaceutical Formulation
Dinesh B. Marathe, Rohini M. Koli, Kunal S. Mahajan, Dr. R. R. Patil, Vinod A. Chaure*
Department of Pharmaceutical Chemistry, J.E.S’s College of Pharmacy, Nandurbar, 425412, Maharashtra, India.
*Corresponding Author E-mail: vinodchaure1992@gmail.com
ABSTRACT:
As an antidepressant, escitalopram oxalate, a pure S-enantiomer derivative of citalopram, blocks selective serotonin reuptake. By preventing serotonin reuptake and boosting serotonin levels in synaptic clefts, this action exerts an antidepressant effect. The analytical method used to identify Escitalopram oxalate in pharmaceutical formulations, both alone and in combination with other antidepressants, was identified in this review. The simultaneous comparison and discussion of eighteen analytical techniques, including HPLC, HPTLC, stability-indicating strategies, UV spectroscopy, hyphenated techniques and bioanalytical procedures, is best demonstrated by this thorough analysis. Analytical development must be validated in order to produce reliable results for regulatory filings. The invention of drugs resulted in a revolution in human health.
KEYWORDS: Escitalopram, Escitalopram oxalate, Review Article, Analytical Methods.
INTRODUCTION:
Escitalopram oxalate (ESC-OX), shown in Fig. no.1 chemically, S(+)-1-(3-dimethylaminopropyl)-1-(4-fluorophenyl)-1, 3-dihydroisobenzofuran-5-carbonitrile hydrogen oxalate, is the pure S-enantiomer racemic bicyclic phthalane derivative of citalopram used as an antidepressant. The molecular weight of Escitalopram Oxalate is 414.43gm. Escitalopram Oxalate is white crystalline powder having melting point 146-149°C. It is Soluble in alcohol, sparingly soluble in water and slightly soluble in acetone1. Escitalopram Oxalate is produced as the oxalate salt for therapeutic use. The empirical formula of escitalopram oxalate is C20H21FN2OC2H2O42. A review of the literature revealed that while there are a various analytical methods for determining ESC in bulk and pharmaceutical formulations.
Analytical techniques such as UV/Visible Spectrophotometry, high performance liquid chromatography, and high performance thin layer chromatography, bioanalytical methods and stability indicating methods3,4.
Figure no 1: Chemical structure Escitalopram Oxalate
PHARMACOLOGICAL PROFILE:
ESC inhibits selective serotonin reuptake SERT. This activity has an antidepressant effect by inhibiting serotonin reuptake and increasing the amount of serotonin in synaptic clefts5. ESC is also recommended for the treatment of generalized anxiety disorder, panic disorder, social anxiety disorder and obsessive-compulsive disorder6.
Table 1: Analysis of Escitalopram Oxalate and Its Combinations Using Spectrophotometric Methods
|
Sr. No |
Drug |
Method |
Linearity(µg/ml) |
Detection (λMax) nm |
(r2) Value |
Ref. |
|
1. |
ESC |
Zero Order Spectroscopic Method |
2-20µg/ml |
238 nm |
0.9999 |
1 |
|
2. |
ESC |
Validation UV Spectrophotometric Method |
5-25µg/ml |
239 nm |
0.9999 |
12 |
|
3. |
ESC+ CLO |
Simultaneous Spectrophotometric Method |
ESC-5-100µg/ml CLO-5-50µg/ml |
ESC-238 nm CLO-273 nm |
ESC-0.9996 CLO-0.9992 |
13 |
|
4. |
ESC+ CLO |
Simultaneous Spectrophotometric Method |
ESC-20-120µg/ml CLO-1-6µg/ml |
ESC-246 nm CLO-230 nm |
ESC-0.999 CLO-0.999 |
14 |
|
5. |
ESC+ ESZ |
Simultaneous Spectrophotometric Method |
ESC-5-50µg/ml ESZ-3-18µg/ml |
ESC-238.0nm ESZ-304.0nm |
ESC-0.9995 ESZ-0.9998 |
15 |
While SSRI antidepressants have equal efficacy to other antidepressants, they are less hazardous in overdose and have better initial tolerability profiles. They are currently considered first line treatment for major depressive disorder7. ESC-OX undergoes hepatic metabolism to form its principle metabolites-desmethylcitalopram or alternatively, the nitrogen moiety of escitalopram may be converted to N– oxide metabolite. Escitalopram is eliminated by both hepatic and renal routes, with the majority of the dose are recovered in urine; 8% of the dose is recovered in the urine as unchanged parent drug. It is expected that escitalopram is excreted in breast milk6.
PHARMACOPOEIAL METHODS FOR ESTIMATION OF ESCITALOPRAM OXALATE:
In both the Indian and United States Pharmacopoeias, escitalopram oxalate is the recognised medication. The use of liquid chromatography for infrared absorption spectroscopy has been reported by USP and IP. According to USP, escitalopram oxalate is analysed using a column (4.6mm 25cm; 5µm), mobile phase methanol, acetonitrile, and buffer (33:7:60%, v/v/v), at a flow rate of 0.6ml/min, and escitalopram oxalate is detected at a wavelength of 237nm8. While n-hexane, ethanol, and trifluoroacetic acid (90:10:0•4%, v/v/v) were used as the mobile phase for the RP-HPLC analysis, a stainless steel column (25cm 4.6, 5µm) mm, packed with octylsilane bound to porous silica, was used. 1.5ml/min of flow and a 226nm detecting wavelength were used9.
ANALYTICAL APPROACHES FOR ESCITALOPRAM OXALATE:
Pharmaceutical analysis using analytical methods is an important aspect of the medication development and validation process. Analytical methods like UV-Visible Spectroscopy1,12-15, High Performance Liquid chromatography (HPLC)18-24, High Performance Thin Layer Chromatography (HPTLC)24-27, Stability Indicating Methods30-34.
UV-VISIBLE SPECTROPHOTOMETRY FOR ESTIMATION OF ESCITALOPRAM OXALATE:
Ultraviolet-visible spectroscopy is the study of interactions between matter and electromagnetic energy in this range10. Many compounds, including a large number of organic molecules, frequently absorb light in the UV-Vis range. While they can also happen at the quantum vibrational levels, the electronic level is where the majority of energy shifts occur. The area of the molecule where the electronic transitions occur is known as the chromophore11. Total five uv-visible spectroscopic methods reported for the analysis of Escitalopram Oxalate in alone and combination using different methods likes zero order and simultaneous estimation methods. Methanol is used as solvent in maximum reported methods. Table no 1 provides a summary of the reported spectrophotometric techniques, including the methods, the detection wavelength, the linearity, and the correlation coefficient1,12-15.
HIGH PERFORMANCE LIQUID CHROMATOGRAPHY FOR ESTIMATION OF ESCITALOPRAM:
In order to separate and measure substances that have been dissolved in solution, high-performance liquid chromatography (HPLC) is a type of liquid chromatography. The quantity of a certain component in a solution can be found out using HPLC16. In HPLC, the stationary phase is a column that holds packing material, the mobile phase is moved through the column by a pump, and the detector displays the retention periods of the molecules. The interactions between the stationary phases, the molecules being studied, and the solvent being utilized affect retention time17. Total seven HPLC methods reported for analysis of escitalopram oxalate in single and combination form with ETI, CLO and FLU. Every HPLC technique has been documented in the literature for the isocratic mode ESC determination. Using a C18 column with dimensions of 250/150 x 4.6 mm; 5m and various combinations of mobile phases including buffer solution with an acidic pH, acetonitrile, and methanol, the separation and identification of the ESC was accomplished. UV/Visible detectors were used for the detection. Retention periods < 12 minutes have been reported for each of these techniques. Low LOD and LOD values for the proposed approaches demonstrate their sensitivity. All of these tried-and-true techniques are touted as being easy, affordable, and time-efficient. Information on the chromatographic parameters, such as mobile phase, flow rate, mode of analysis, and detection wavelength, will be provided by the literature review that is summarized in Tables No. 2 and 3 18-24.
Table.2: Analysis of Escitalopram and Its Combinations Using HPLC (Mobile Phase Compositions, linearity, retention time, λmax and correlation coefficient)
|
Sr. No. |
Drugs |
Mobile Phase Compositions |
Linearity µg/mL |
Rt (min) |
λma x nm |
r2 |
Ref. |
|
1. |
ESC |
Buffer (pH- 3.8) : ACN : MeOH (67:28:5%, v/v/v) |
50-200 |
14 |
238 |
0.997 |
18 |
|
2. |
ESC |
ACN : MeOH : 5mM Ammonium Acetate Buffer (pH-3.0) (30:20:50%, v/v/v) |
- |
5.36 |
238 |
0.9997 |
19 |
|
3. |
ESC |
ACN : Buffer(pH-4.0) (25:75%, v/v) |
2.5-80 |
3.2 |
240 |
0.9994 |
20 |
|
4. |
ESC+ ETI |
0.02 M Potassium Dihydrogen Orthophosphate: CAN (40:60%, v/v) |
ESC-20-120 ETI-1-6 |
ESC-2.8 ETI-4.1 |
254 |
0.998 0.998 |
21 |
|
5. |
ESC+ CLO |
Acetonitrile 50 mM Phosphate Buffer(pH-4.3) : 10mM Triethylamine (70:30%, v/v/v) |
ESC-5.0-25.0 CLO-0.5-2.5 |
ESC-5.90 CLO-7.90 |
268 |
ESC-0.999 CLO-0.999 |
22 |
|
6. |
ESC+ CLO |
Buffer(pH- 3.0±0.05) : ACN (50:50%, v/v) |
ESC-20-120 CLO-1-6 |
ESC-2.840 CLO-4.007 |
240 |
ESC-0.99920 CLO-0.99918 |
23 |
|
7. |
ESC+ FLU |
ACN : Potassium Phosphate Buffer (pH- 7.0) (60:40 %, v/v) |
ESC-5-25 FLU-10-50 |
ESC-6.5 FLU-2.8 |
231 |
ESC-0.992 FLU-0.999 |
24 |
Table.3: Analysis of Escitalopram and Its Combinations Using HPLC (Column Specifications, Detector, Flow rate and mode of analysis)
|
Sr. No |
Drugs |
Mode of analysis |
Column, Internal diameter and Particle Size |
Flow rate. |
Detector |
Ref. |
|
1. |
ESC |
Isocratic |
Inertsil ODS-2, 250 ×4.6mm, 5 μm, |
1.0 mL/min |
PDA, ESI-MS, UV |
18 |
|
2. |
ESC |
Isocratic |
Kromosil (250 × 4.6) mm, 5 μm |
1 mL/min |
UV/VIS |
19 |
|
3. |
ESC |
Isocratic |
C18 Column (150mm ×4.6 mm, 5µm) |
1mL/min |
UV/VIS |
20 |
|
4. |
ESC+ ETI |
Isocratic |
C18 (250×4.6 mm, 5µm) |
1 mL/min |
UV/VIS Detector |
21 |
|
5. |
ESC+ CLO |
Isocratic |
ODS Hypersil C18 Column (250 × 4.6mm) |
1.5 mL/min |
UV/VIS Detector |
22 |
|
6. |
ESC+ CLO |
Isocratic |
Hypersil ODS C18 Column (250×4.6mm, 5µm) |
1.0 mL/min |
UV Deuterium detector |
23 |
|
7. |
ESC+ FLU |
Isocratic |
Hibar C18 Column 250mm × 4.6nm id, 5 |
1.2mL/mi |
UV Detector |
24 |
HIGH PERFORMANCE THIN LAYER CHROMATOGRAPHY FOR ESTIMATION OF ESCITALOPRAM:
High Performance Thin Layer Chromatography (HPTLC) is a sophisticated and automated variant of thin-layer chromatography with improved and advanced separation efficiency and detection limits. It is also known as High Pressure Thin Layer Chromatography/Planar chromatography or Flat-bed chromatography. It is an effective analytical technique that works for both qualitative and quantitative problems 25. HPTLC is a useful method for accurate identification since it can provide chromatographic fingerprints that can be seen and preserved as digital images 26. Only one HPTLC method has been reported in combination of ESC with CLO. Chromatographic separation achieved by using pre-coated silica gel aluminum plate 60F254 as stationary phase using CAMAG Linomat V semiautomatic sample applicator. The mobile phase was selected methanol–toluene–triethylamine (1:3.5:0.1, v/v/v) with UV detection monitored at 253 nm. The retention factor was ESC and CLO were 0.36 and 0.49, respectively with a correlation coefficient (r2) of 0.998, the results were shown to be linear in the concentration range of 50-150 ng/band for ESC and 5-15 ng/band for CLO. The method was validated for precision, accuracy, specificity, and Ruggedness as per ICH guideline 27.
STABILITY INDICATING METHODS FOR ESTIMATION OF ESCITALOPRAM:
Stability indicating methods' main goal is to provide information on the stress testing environment in order to assess the stability of pharmaceutical substances and products. The API is distinguished from any potential metabolic byproducts using SIMs 28. SIM is a quantitative analytical method that determines the quantity of API that has changed as a result of deterioration under various stress conditions 29. Total five methods have been reported for the estimation of ESC in different stress conditions.
Table 4: Stability-indicating methods for analysis of Escitalopram
|
Sr. No |
Name of drug |
Mobile phase composition |
Detection λ (max) nm |
Linearity µg/ml |
Rt./Rf (in.min) |
r2 |
Ref. |
|
1. |
ESC+CLO |
ACN : 50mM Phosphate Buffer : 10mM Triethylamine (70:30%, v/v) |
268 |
ESC-5.0-25.0 CLO-0.5-2.5 |
5.90 7.94 |
0.999 0.999 |
30 |
|
2. |
ESC+LMF |
0.1% OPA (pH-4.0) : ACN (60:40%, v/v) |
230 |
ESC-75 LMF-100 |
3.045 3.661 |
ESC - 0.999 LMF- 0.999 |
31 |
|
3. |
ESC+LMF |
ACN : 0.01% H3PO4 in Water (35:65%, v/v) |
212 |
ESC-20-120 LMF-15-90 |
ESC-3.045 LMF-3.661 |
ESC - 0.999 LMF- 0.999 |
32 |
|
4. |
ESC+LMF |
0.01 N KH2PO4 Buffer : ACN (50:50%, v/v) |
230 |
ESC-25-150 LMF-18.75-112.5 |
3.279 2.232 |
0.9993 0.9998 |
33 |
|
5. |
ESC +ETI |
ACN : Methanol : 0.002 M Ammonium Acetate Buffer (pH-4.5) (30:20:50%, v/v/v) |
227 |
ESC-30-70 ETI-3.0-7.0 |
2.3 5.7 |
ESC- 0.999 ETI- 0.999 |
34 |
Table.5: Analysis of Escitalopram and Its Combinations Using Stability Indicating Method
|
Sr.No |
Drugs |
Mode of analysis |
Column, Internal diameter and Particle Size |
Flow rate. |
Detector |
Ref. |
|
1. |
ESC+CLO |
Isocratic |
Hypersil C18 Column (250×4.6 mm, 5µ) |
1.5 |
UV/VIS |
30 |
|
2. |
ESC +LMF |
Isocratic |
Kromosil (250×4.6 mm, 5µ) |
1.0 |
PDA |
31 |
|
3. |
ESC+LMF |
Isocratic |
ODS(250×4.6 mm, 5µ) |
1.0 |
PDA |
32 |
|
4. |
ESC+LMF |
Isocratic |
BDS C18 (150×2mm, 3µ) |
0.9 |
PDA |
33 |
|
5. |
ESC+ETI |
Isocratic |
C18 Column Inertsil ODS 3V, (150mm×4.6mm, 5µ) |
1.0 |
DAD |
34 |
The isocratic mode ESC determination has been published in the literature using the SIMs technology. The separation and identification of the ESC were completed using a C18 column with dimensions of 250 x 4.6 mm; 5 µm and several combinations of mobile phases, including Water, Acetonitrile and methanol. The detection was carried out using PDA detectors 30-34. Table no 4 and 5 provide all summery.
DISCUSSION:
Seventeen analytical methods available for the Estimation of drug ESC in single and combination of different formulations includes CLO, ESZ, ETI, FLU and LMF. Using different analytical techniques like UV-Spectrophotometry, HPLC, HPTLC and stability-indicating methods. Establishment of about seventeen analytical methods applied for the determination of ESC has also been reported.
Figure no 2: Total Analytical Methods of ESC Published During 2007- 2021
Figure no 2: Total Analytical Methods of ESC Published During 2007- 2021
CONCLUSION:
The main goal of the compilation of review is to gather as much information as is possible about the analytical methods of Escitalopram oxalate and thoroughly research it. According to the results of this survey, HPLC, HPTLC, UV/Visible spectrophotometry, and stability indicating techniques have a very limited number of available analytical methods. The current review article can give the researcher the key details regarding the many techniques used for ESC analysis as well as details regarding the wide range of possibilities available.The review of different analytical methods used for determination of ESC in bulk and in its combined pharmaceutical formulations. An analysis of the literature published between 2007 and 2021 described analytical techniques for ESC estimation Figure no 2. Several analytical techniques are used for analysis. One of the most commonly used solvents for sample preparations is methanol. The different solvents used for separation of ESC include methanol, acetonitrile and buffer or their combination in appropriate proportion. Several methods reported utilizing various analytical techniques for ESC were contrasted in Figure no 3.
CONFLICT OF INTEREST:
The authors have no conflicts of interest regarding this investigation.
ACKNOWLEDGEMENT:
Authors are thankful to Principal, J.E.S’s College of Pharmacy, Nandurbar, 425412, for providing necessary library facilities.
ABBREVIATIONS:
API- Active Pharmaceutical ingredient
AUC- Area under curve
HPLC- High performance liquid chromatography
HPTLC-High performance thin layer chromatography
LC- Liquid chromatography
OPA- o- phosphoric acid
SIM- stability indicating method
TEA- Triethylamine
LMF- L-Methylfolate
MeOH- Methanol
ACN- Acetonitrile
FLU- Flupentixol
ETI- Etizolam
ESZ- Eszopiclone
CLO- Clonazepam
IP- Indian Pharmacopoeia
USP- United States Pharmacopoeia
ESC- Escitalopram
ESC-OX- Escitalopram oxalate
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Received on 08.04.2023 Modified on 17.05.2023
Accepted on 22.06.2023 ©Asian Pharma Press All Right Reserved
Asian J. Pharm. Ana. 2023; 13(3):217-221.
DOI: 10.52711/2231-5675.2023.00035