ASIAN JOURNAL OF CHEMISTRY ASIAN JOURNAL OF CHEMISTRY https://doi.org/10.14233/ajchem.2017.20541 INTRODUCTION A high submicellar liquid chromatographic method, where organic solvent content is high and surfactants are presents in the form of small cluster in the mobile phase was developed. In this submicellar liquid chromatography micelles exist in the form of monomers. These monomers associated with the stationary phase and give hither retention time of pharma- ceutical drugs. Several reports reveled that the high organic solvent content in the mobile phase decreases the thickness of the surface coating [1-3]. A systematic perusal of literature reveled that hitherto methods [4,5] using high submicellar liquid chromatography to optimize chromatographic condi- tions are developed and validated. An high submicellar liquid chromatographic method using micellar mobile phase containing surfactant above its critical micellar concentration [6,7] was developed and validated for the determination of baclofen in active pharmaceutical ingredient (API) and pharmaceutical formulations. Baclofen i.e., 4-amino-3-(4-chlorophenyl)butanoic acid (Fig. 1), γ-amino butyric acid (GABA), introduced as race mate in the therapy of muscle spasticity, is still the classical prototype of the selective GABABR agonists [8]. It is primarily used to treat spasticity and is in the early research stages for the treatment of alcoholism. It is also used by compounding pharmacies in A Submicellar Liquid Chromatographic Method for Quantitative Determination of Muscle Relaxant Drug Baclofen in Solubilized System HITESH MALVIA 1 , ASHOK KUMAR 1,* , PRATIBHA SHARMA 1 and RITESH MISHRA 2 1 School of Chemical Sciences, Devi Ahilya University, Khandwa Road, Indore-452 001, India 2 API Research & Development Department, Medilux Laboratories Pvt. Ltd., Pithampur-454 775, India *Corresponding author: E-mail: drashoksharma2001@yahoo.com Received: 25 January 2017; Accepted: 31 March 2017; Published online: 13 May 2017; AJC-18384 A high performance liquid chromatography method, using micellar solution above the critical micellar concentration (CMC) has been developed and validated to quantify baclofen (a muscle relaxant drug) in active pharmaceutical ingredients and pharmaceutical formulations. Process optimization was done at various conditions such as different surfactants, surfactant concentration, pH of buffer solution, solvent composition, solvent selection and different HPLC columns. An isocratic HPLC mode, column temperature 35 °C, Intersil ODS-3 V 250 × 4.6, 5 μm column, 0.8 mL/min mobile phase flow rate and UV detection wavelength at 220 nm was used for the purpose. The method was validated as per International Conference on Harmonization (ICH) guidelines viz., specificity, linearity, range, inter and intra-day precision, accuracy (recovery) and robustness. Forced degradation conditions such as basic, acidic, oxidative, thermal degradation and photolytic are applied to prove the stability indicating nature of the proposed method. Keywords: Critical micelle concentration, Micellar liquid chromatography, Sodium dodecyl suphate, Baclofen. Asian Journal of Chemistry; Vol. 29, No. 7 (2017), 1509-1514 topical pain creams as a muscle relaxant. The most pre- dominant pharmacological effects of baclofen are its muscle relaxant, anti-nociceptive and anti-drug craving properties [9,10] as well as the reduction in cognitive behaviour [11]. Baclofen is used clinically for the treatment of spasticity asso- ciated with brain and spinal cord injuries [12], drug addiction and alcoholism [13,14], gastroesophageal reflux disease (GERD) [15], cancer pain [16] and overactive bladder [17-19]. NH 2 COOH Cl Fig. 1. Baclofen [4-amino-3-(4-chlorophenyl)butanoic acid] A systematic perusal of literature reveled that hitherto a few methods [20-24] are available for the analysis of baclofen. However, most of them suffer from various bottle-necks such as long analysis time, inaccurate analysis and tedious workup procedures. Hence keeping in view to overcome the short- comings of existing methods, it was thought to develop a novel, MLC quantitation strategy for the determination of baclofen in solubilized systems.