FORM-2 THE PATENTS ACT, 1970 (39 OF 1970) & The Patent Rules, 2003 COMPLETE SPECIFICATION Sec l0-Rule l3 A. STABLE ORAL DOSAGE FORM OF LOFEXIDINE INDOCO REMEDIES LIMITED Indian R-92-93, T.T.C Industrial Area, Thane Belapur Road, Rabale MIDC Navi Mumbai-400701 The following complete specification describes the invention and the manner in which it is to be performed. Field of Invention: The present invention relates to a stable oral dosage form of Lofexidine. More specifically, the present invention relates to a stable oral dosage form of Lofexidine and a method of preparing the same, which is chemically stable at room temperature and is devoid of sticking and content uniformity issues. The present invention further provides apparatus and methods to resolve content uniformity, sticking, and dissolution related hurdles. Background of the Invention: Lofexidine is a α2-adrenergic receptor agonist analogue of clonidine that acts centrally to suppress opiate withdrawal symptoms. The drug has been available for use as a non-opioid medication for opioid detoxification in the United Kingdom under the label BritLofex since 1992. Lofexidine works by relaxing blood vessels so that blood can flow more easily through the body. The Lofexidine, 2-[l[(2, 6-Dichlorophenoxy) ethyl]-4, 5-dihydro-lH-imidazoline (CAS No. 31036-80-3) has the structure shown in formula I below: The USFDA approved Lofexidine tablets on May 16, 2018, with the brand name Lucemyra, manufactured by USWM LLC. WO2009120735A1 discloses the trans-mucosal composition comprising of Lofexidine and method for treating opiate withdrawal symptoms and said composition is formulated in tablet, gel or adhesive dosage form. US11065205B2, provides tablet made up of three parts core, first coating layer and second coating layer. The first part core is made up of active ingredient and excipient and core is coated with combinatipn of wax and hydroxypropyl cellulose in ratio 40:60 to 60:40 w/w forming a second part of tablet. This second part is coated with active ingredient and excipients by forming third part and immediate pulsed release of excipients. US20130095174A1 provide composition and method for accelerating rate of delivery of Lofexidine to the systemic circulation by trans-mucosal administration through nasal, sublingual or buccal routes to provide rapid response in treatment of opiate addicts, migraine, neuropathic pain, and other therapeutic indications. The main excipient involve in such delivery is permeation enhancer and selected from the group consisting of fatty acids, fatty acid esters, fatty alcohols, fatty acid esters of lactic acid or glycolic acid, glycerol triesters, glycerol diesters, glycerol monoesters, triacetin, short chain alcohols, and mixtures thereof. The shelf life of solid dosage form depends on various physical and chemical parameters. The stability can be affected by physical parameters such as temperature, pressure, moisture content etc. Also, chemical parameters like chemical composition, endothermic or exothermic reactions are responsible for affecting stability. The Lofexidine tablets are marketed in the USA under the brand name Lucemyra. From the information published by the USFDA in the chemistry review section of freedom of information (FOI), the following issues are highlighted: • Sticking of tablets at accelerated stability conditions at 40°C./75% RH. • Two of the drug substance impurities exceed the ICH qualification threshold. • One of the drug product impurities exceeds the ICH qualification threshold. • Due to the sticking issue observed in accelerated stability conditions at 40°C /75% RH desiccant is considered important for stability. The drug substance concentration in Lofexidine tablets is very low, approximately 0.17% w/w, due to which there are issues with the content uniformity and assay of the compressed tablets. The problem in the preparation of pharmaceutical preparations, in particular solid dosage forms containing Lofexidine as an active ingredient, is the low content of active ingredient required in the dosage form. Since the active ingredient has to be admixed with a relatively large amount of excipients, it is difficult to obtain a homogenous distribution of the drug substance. Drug content uniformity among individual dosage units of pharmaceutical products has received increasing attention over recent years. The size and shape of the drug substance is crucial for a homogenous distribution in a dosage form. Large and irregularly shaped particles can easily decrease content uniformity. Poor content uniformity has been shown to cause a decrease in bioavailability. To ensure drug content uniformity, each dosage unit should contain the active drug within a prescribed range as per the United States Pharmacopoeia and the European Pharmacopoeia. Therefore, there remains a need for stable and industrially acceptable pharmaceutical composition comprising Lofexidine or a salt thereof whose manufacturing process is simple, reliable and economical. The inventors of the present invention have successfully solved the aforementioned problems by developing a stable Lofexidine composition and process for its preparation, along with an improved dissolution method. Additionally, the process also solves sticking problems and issues related to content uniformity. Object of the Invention: The object of the invention is to provide a stable oral dosage form comprising Lofexidine and pharmaceutically acceptable excipients. Another object of the present invention is to provide a stable oral dosage form comprising Lofexidine, diluent, stabilizer, binder, surfactant, lubricant and coating agent. Another object of the present invention is to provide a stable oral dosage form comprising Lofexidine, diluent, disintegrant, stabilizer, binder, surfactant, lubricant and coating agent. Another object of the present invention is to provide a stable oral dosage of Lofexidine such as a tablet, capsule or granules. One another object of the present invention is to provide a stable oral dosage form comprising Lofexidine which is devoid of sticking and content uniformity issues. Another object of the present invention is to provide a stable oral dosage form comprising Lofexidine, and pharmaceutically acceptable excipients which exhibits a complete and consistent dissolution profile. Yet another object of the present invention is to provide a stable oral dosage form comprising of Lofexidine, lactose, microcrystalline cellulose, citric acid, povidone, sodium lauryl sulphate, calcium stearate and Opadry AMB II. Yet another object of the present invention is to provide a stable oral dosage form comprising of Lofexidine, lactose, microcrystalline cellulose, citric acid, povidone, sodium lauryl sulphate, sodium starch glycolate, calcium stearate and Opadry AMB II. A further object of the present invention is to provide a method for preparing a stable solid oral dosage form comprising Lofexidine. Further, another object of the present invention is to develop a dissolution method for a stable oral dosage form comprising Lofexidine. Another object of the present invention is the development and use of rate controlled granulating solvent addition vessel to achieve uniform and consistent content uniformity due to the very low quantity of API in formulation. A further object of the present invention is to provide a stable oral dosage form comprising Lofexidine for the treatment of opioid withdrawal symptoms. Summary of the Invention; In one aspect, the present invention relates to a stable solid oral dosage form comprising of Lofexidine and pharmaceutically acceptable excipients. According to one aspect, the present invention provides a process for manufacturing stable solid oral dosage form comprising Lofexidine and pharmaceutically acceptable excipients. According to another aspect, the present invention provides a stable solid oral dosage form comprising Lofexidine, which is devoid of sticking and content uniformity issues. According to another aspect, the present invention provides a stable solid oral dosage form comprising Lofexidine, for mitigation of opioid withdrawal symptoms. According to one aspect, the present invention provides a stable solid oral dosage form comprising Lofexidine and pharmaceutically acceptable excipients packaged in pharmaceutically acceptable containers. Detailed Description of the Invention: The present invention, in one aspect, relates to a stable solid oral dosage form comprising of Lofexidine and pharmaceutically acceptable excipients. According to another aspect, the present invention provides a stable solid oral dosage form comprising Lofexidine, to overcome the problem of sticking and content uniformity. According to one embodiment, the present invention provides a stable solid oral dosage form comprising Lofexidine, a diluent, a disintegrant, a stabilizer, a binder, a surfactant, a lubricant, a coating agent and pharmaceutically acceptable excipients. The present invention, in one embodiment, provides a stable solid oral dosage form comprising of Lofexidine, sodium starch glycolate as disintegrant and pharmaceutically acceptable excipients. According to one embodiment, the present invention provides a stable solid oral dosage form comprising 0.17% Lofexidine, 30 % to 90 % diluent, 2 % to 10 % disintegrant, 5 % to 15% stabilizer, 0.5 % to 5% binder, 0.2 % to 2 % surfactant, 1 % to 3 % lubricant, 1 % to 3 % coating agent and pharmaceutically acceptable excipients. According to one embodiment, the present invention provides a stable solid oral dosage form comprising Lofexidine, lactose, microcrystalline cellulose, sodium Starch glycolate, citric acid povidone, sodium lauryl sulphate, calcium stearate, opadry OY-S-9480 (HPMC base material), and pharmaceutical^ acceptable excipients. According to one embodiment, the present invention provides a stable solid oral dosage form comprising Lofexidine, lactose, microcrystalline cellulose, sodium starch glycolate, citric acid, povidone, sodium lauryl sulphate, calcium stearate, opadry AMB II (PVA base material), and pharmaceutically acceptable excipients. According to one embodiment, the present invention provides a stable solid oral dosage form comprising: 0.17 % Lofexidine, 30 % to 80 % lactose, 3 % to 6 % microcrystalline cellulose, 3 % to 6% sodium starch glycolate, 10 % to 12 % citric acid, 0.5 % to 1.5 % povidone, 0.5 % to 0.8 % sodium lauryl sulphate, 1.20 % to 2 % calcium stearate, 1.25 % to 2.25 % coating agent and other pharmaceutical acceptable excipients. According to one embodiment, the present invention provides a stable solid oral dosage form comprising 0.17% Lofexidine, 75% lactose, 4.91% microcrystalline cellulose, 10.6% citric acid, 0.95% povidone, 0.60% sodium lauryl sulfate, 4.31% sodium starch glycolate, 1.72% calcium stearate and 1.72% of Opadry AMB II, wherein said stable composition shows excellent content uniformity without any sticking problems. According to one embodiment, the present invention provides a stable solid oral dosage form comprising 0.17% Lofexidine, 75% lactose, 4.91% microcrystalline cellulose, 10.6% citric acid, 0.95% povidone, 0.60% sodium lauryl sulfate, 4.31% sodium starch glycolate, 1.72% calcium stearate and 1.72% of Opadry AMB II, wherein coating agent comprises of polyvinyl alcohol, titanium dioxide, sodium lauryl sulphate, talc, FD&C yellow, FD&C blue, glyceryl mono and dicaprylocaprate, FD&C yellow, and FD&C blue or combination thereof to overcome problem of sticking and content uniformity. According to one embodiment, the present invention provides a stable oral dosage form comprising Lofexidine or its acceptable salt, sodium starch glycolate as disintegrant and pharmaceutical acceptable excipients, wherein the composition is coated with coating solution comprising,polyvinyl alcohol, titanium dioxide, sodium lauryl sulphate, talc, FD&C yellow, FD&C blue, glyceryl mono and dicaprylocaprate, FD&C yellow, and FD&C blue or combination thereof to overcome problem of sticking and content uniformity. According to one embodiment, the present invention provides a stable solid oral dosage form comprising 0.17% Lofexidine, 75% lactose, 4.91% microcrystalline cellulose, 10.6% citric acid, 0.95% povidone, 0.60% sodium lauryl sulfate, 4.31% sodium starch glycolate, 1.72% calcium stearate and 1.72% of Opadry AMB II. According to one embodiment, the present invention provides an apparatus shown in figure 1 to achieve uniform pouring of API in pharmaceutical excipient base to prepare tablets with enhanced content uniformity. The pharmaceutically acceptable excipients contained in the stable solid oral dosage form of the present invention include diluent, disintegrant, stabilizer, binder, surfactant, lubricant, coating agent, and other conventional agents that may be typically used in formulating a stable solid oral dosage form. Diluents that can be used in the solid dosage form of the present invention include, but are not limited to, sugar, sorbitol, xylitol, mannitol, lactose, carboxymethyl cellulose, microcrystalline cellulose, potato, maize, wheat, arrowroot, amylopectin and combinations thereof. Disintegrants that can be used in the solid dosage form of the present invention include, but are not limited to, sodium starch glycolate, croscarmellose, crospovidone and combinations thereof. Stabilizers that can be used in the solid dosage form of the present invention include, but are not limited to, citric acid monohydrate, polyvinylpyrrolidone, sodium alginate, tweens, polaxamer and combinations thereof. Binders that can be used in the solid dosage form of the present invention include, but are not limited to, povidone, cellulose, gelatin, cellulose derivatives sucrose, mannitol, polyethylene glycol and combinations thereof. Surfactants that can be used in the solid dosage form of the present invention include, but are not limited to, sodium lauryl sulfate, polyoxyethylene stearates, tween and combinations thereof. Lubricants that can be used in the solid dosage form of the present invention include, but are not limited to, calcium stearate, stearic acid, talc, magnesium stearate and combinations thereof. Coating agents that can be used in the solid dosage form of the present invention include, but are not limited to, opadry AMB, opadry OY-S, Ti02 and hydroxypropyl cellulose hydroxypropyl methylcellulose, hydroxypropyl methylcellulose, methylene chloride, dyes and combinations thereof. In one embodiment, the solid oral dosage form is in the form of a tablet or granules. The tablet is coated with a coating agent. The coating is for aesthetic purposes and provides good appearance to the final dosage form. According to one embodiment, the present invention provides a stable solid oral dosage form comprising 0.17 % Lofexidine, 30 % to 80 % lactose, 3 % to 6 % microcrystalline cellulose, 10 % to 12 % citric acid, 0.5 % to 1.5 % povidone, 0.5 % to 8 % sodium lauryl sulphate, 1.2 % to 2% calcium stearate, 1.25 % to 2.25 % opadry AMB II (PVA base material), and pharmaceutically acceptable excipients According to one aspect, the present invention provides a process for manufacturing a stable, solid oral dosage form comprising Lofexidine and pharmaceutically acceptable excipients. In one embodiment, the present invention provides a process for the preparation of stable injectable composition comprising: 1) Preparing blend by mixing stabilizer, diluent with binder. 2) Preparing granulating liquid by adding API to a mixture of binder and surfactant. 3) Adding the granulating liquid of step 2 to the blend of step 1. 4) Preparing granules by drying and milling the wet mass of step 3. 5) Adding disintegrate and lubricant to the granules of step 4 and compressing same to form a tablet. 6) Coating of tablet using coating agent. 7) Packaging of coated tablet in suitable packaging material. In one embodiment, the present invention provides a process for the preparation of stable injectable composition comprising: 1) Preparing blend by mixing stabilizer, diluent with binder. 2) Preparing granulating liquid by adding API to a mixture of binder and surfactant. 3) Adding the granulating liquid of step 2 to blend of step 1 at a controlled rate by using a modified vessel. 4) Preparing granules by drying and milling the wet mass of step 3. 5) Adding disintegrant and lubricant to the granules of step 4 and compressing same to form a tablet. 6) Coating of a tablet using coating agent. 7) Packaging of a coated tablet in suitable packaging material. In one embodiment, the present invention provides a process for the preparation of stable injectable composition comprising: 1) Preparing the blend by mixing citric acid, microcrystalline cellulose with povidone. 2) Preparing granulating liquid by adding Lofexidine or its salt to a mixture of binder and surfactant. 3) Adding the granulating liquid of step 2 to the blend of step 1 at controlled rate by using a modified vessel. 4) Preparing granules by drying and milling the wet mass of step 3. 5) Adding sodium starch glycolate and sodium lauryl sulphate to the granules of step 4 and compressing same to form a tablet. 6) Coating of tablet using opadry AMB II agent. 7) Packaging of coated tablet in suitable packaging material. According to one aspect, the present invention provides a method for mitigation of opioid withdrawal symptoms to facilitate abrupt opioid discontinuation in adults. According to one aspect, the present invention provides a stable, solid oral dosage form comprising Lofexidine and pharmaceutically acceptable excipients packaged in pharmaceutically acceptable containers. According to one embodiment, the present invention provides a stable, solid oral dosage form comprising Lofexidine and pharmaceutically acceptable excipients packaged in HDPE bottles. According to one embodiment, the present invention provides a stable, solid oral dosage form comprising Lofexidine and pharmaceutically acceptable excipients packaged in blister pack. According to one embodiment, the present invention provides a stable, solid oral dosage form comprising Lofexidine and pharmaceutically acceptable excipients packaged in a strip pack. According to one aspect, the present invention provides a method for performing a dissolution test. According to one embodiment, the present invention provides a dissolution method for a solid dosage form comprising Lofexidine, lactose, citric acid, povidone, microcrystalline cellulose, calcium stearate, sodium lauryl sulphate, sodium starch glycolate, opadry AMB II (PVA base material), and pharmaceutically acceptable excipients. During the development of the Lofexidine tablet, the inventors of the present invention tried various excipients and processes to achieve a stable and compatible dosage form. The main issues that arose are as follows: 1) Assay and content uniformity due to low quantity of active drug. 2) Sticking of tablets. 3) Incomplete drug release during dissolution testing. To cope with above issues, the following experiments were carried out to build a good quality product by modifying and improving the product composition, manufacturing process, and testing methods. The details of experiments are provided as follows: Experiment No. 1: Content Uniformity This section provide experiment conducted to solve content uniformity and sticking issues. Content uniformity of the active pharmaceutical ingredient is a critical quality attribute of the tablet dosage form, ensuring reproducible drug potency. The acceptable content uniformity value assures correct mixing of the active agent in the tablet base and prohibits particle segregation during storage and the compression process itself. This factor is mainly dependent on various parameters, such as the quantity and characteristics of the active agent, excipients and manufacturing process. Various manufacturing technologies, such as rapid mixer granulation, order of mixing, and top spray granulation, have improved the manufacturing process and quality of low dose drug products by achieving predefined objectives of content uniformity during mixing and formulation of low dose drugs. During accelerated storage conditions Lofexidine tablets showed sticking of tablets, and this information is disclosed in the chemistry review section of freedom of information published by the USFDA. The coating agent is one of the important excipients of tablet composition, which aids in solving issue like palatability, texture, deterioration, stability etc. To solve the sticking problem, hydroxypropyl methyl cellulose based coating was replaced with polyvinyl alcohol based coating material. The coating material of marketed Lucemyra tablets is opadry OY-S-9480, which comprises hydroxypropyl cellulose, titanium dioxide, propylene glycol and FD&C yellow #6/sunset yellow FCF aluminum lake & FD&C blue #2/indigo carmine aluminum lake. The coating solution of opadry-AMB II used in the present invention comprises of polyvinyl alcohol, titanium dioxide, sodium lauryl sulphate, talc, FD&C yellow #6/sunset yellow FCF aluminum lake, FD&C blue #2/indigo carmine aluminum lake, glyceryl mono and dicaprylocaprate, FD&C yellow #6/sunset yellow FCF aluminum lake, and FD&C blue #2/indigo carmine aluminum lake. The disintegration rate of the marketed Lucemyra tablets, i.e. batch no. 4099314-R was found to be faster than batch no. 3405695, therefore a disintegrating agent was added to boost up disintegration. The inventors of the present invention prepared tablets with the following processes and evaluated them further to obtain the best suitable process for making Lofexidine tablets with good content uniformity. A) Wet granulation with binder addition by pouring method. B) Wet granulation with binder addition by tubing and peristaltic pump. C) Wet granulation by Top Spray. D) Wet granulation where binder addition is controlled with the aid of a modified vessel. The table no 1 represents quality and quantity of excipients along with modification in binder addition process during manufacturing process. Table No. 1 s r. N 0. Ingredients Referen ce Product (Lucemy ra Tablet 0.18 mg) Test Product (Lofexidi ne Tablet 0.18 mg) Test Product (Lofexidi ne Tablet 0.18 mg) Test Product (Lofexid ine Tablet 0.18 mg) Test Product (Lofexid ine Tablet 0.18 mg) Manufacturin g process - A B C D Batch No. - LGF/R/0. 18/011 LGF/R/0. 18/014 LGF/R/ 0.18/022 LGF/R/ 0.18/036 1 Lofexidine hydrochloride 0.2 0.2 0.2 0.2 0.2 2 Lactose 92.6 92.6 92.6 92.6 87 3 Citric acid 12.3 12.3 12.3 12.3 12.3 4 Povidone 1.1 1.1 1.1 1.1 1.1 5 Microcrystallin e cellulose 5.7 5.7 5.7 5.7 5.7 6 Calcium stearate 1.4 1.4 1.4 1.4 2 7 Sodium lauryl sulphate 0.7 0.7 0.7 0.7 0.7 Sodium Starch 5 Glycolate Opadry OY-S- 8 9480 (HPMC base material) 2 2 2 ~_ ™^ Opadry AMB 9 II (PVA base material) —— —— —— 2 2 Binder Binder addition Binder addition Binder addition addition by tubing Fluidized bed is controlle Process by pouring and d with method peristaltic processer aid of 1 pump modified 0 vessel 1 1 Manufacturing process Wet granulati on Wet granulatio n Wet granulatio n Wet granulati on Wet granulati on Wet granulation process used during experimentation is as follows - 1) Citric acid, lactose, microcrystalline cellulose and povidone were mixed in suitable mixer. 2) Povidone, sodium lauryl sulfate and Lofexidine mixed together to form granulating liquid. 3) Granulating liquid of step 2 was added to dry mixed powder of step 1 using modified vessel at controlled rate of addition. 4) Drying of wet mass of step 3 was done using fluid bed processor and milling of dried granules was carried out using multimill with different screen sizes. 5) Calcium stearate (and Sodium starch glycolate for batch no LGF/R/0.18/036) was/were sifted through suitable sieves and was added to milled granules of step 4 and then compressed to form tablet. 6) Resultant tablet was coated with opadry AMB II or or opadry OY-S-9480. 7) Then resultant tablets were packed in suitable packing material. All above batches were evaluated for content uniformity test and result are tabulated in table no 2. Table no 2: Tabl ets cou nt Specif icatio n Lucymyr a (Batch no -3405695) Lucymyr a (Batch no-4099314- R) Batch No.: LGF/R /0.18/0 11 Batch No.: LGF/R/0.18/ 014 Batch No.: LGF/R/0.18/ 022 LGF/R /0.18/0 36 Manufacturi ng process - A B C D Details - - Binder additio nby pouring method Binder addition by tubing and peristaltic pump Fluidized bed processer Binder additio nis controll ed with aid of modifie d vessel 1 For 10 dosag e units: Accep tance value < Ll% 97.7 97.3 97.3 93.4 81.5 95.1 2 95.9 99.1 98.8 90.1 102.4 96.4 3 95.7 101.1 92.3 94.2 97.5 98.0 4 93.1 93.3 95.9 99.9 101.9 95.3 5 96.1 94.8 94.6 88 101.1 96.6 6 For 30 dosag e units Accep tance value < Ll% and 96 97.0 90.4 90.4 103 99.7 7 97.4 95.1 95.2 87.2 101.7 96.3 8 91.5 100.2 94.9 83.9 83.4 98.0 9 96.7 95.1 92.2 93.4 102.6 95.9 10 93.6 99.6 91.1 86.4 81.8 100.8 Min. 91.5 93.3 90.4 83.9 81.5 95.1 Max no indivi dual conte nt of any 97.7 101.1 98.8 99.9 103 100.8 Avg. 95.4 97.3 94.3 90.7 95.69 97.2 %R SD 2.09 2.72 2.9 5.14 9.85 1.94 dosag e unit is less than (1-L2 X 0.01) AV valu M or more than 7.9 7.6 10.7 19 25.42 5.8 e (1+L2 X 0.01) M.(L1 is 15,0 and L2 is 25.0) NLT 90.0% Assa w/w and 97.6 96.7 96.4 90.5 94.3 97.4 y NMT 110% w/w Rem s Shows low By Fluidized Content ark Shows and variable bed processer uniform low content content ity as content uniformity uniformity as well as uniform with higher result depicts assay ity with AV value. variable of CU higher Adsorption of content results AV APIin silicon uniformity were value. tubing of around 4-5% with higher AV value. within specific ation. Remark: The content uniformity of batch no. LGF/R/0.18/036 was within limits of specification; therefore, this batch was further optimised to resolve stickiness issues. Experiment No. 2: Sticking of tablets - Batch no. LGF/R/0.18/014, in which qualitative and quantitative composition as well as packaging material are identical to marketed Lucemyra tablet. Packaging material for the LGF/R/0.18/036 batch is the same as batch no. LGF/R/0.18/014. Both batches were evaluated in order to study physical parameters during stability storage and results for same are provided in table no 3 - Table no 3. Test product (Lofexidine tablet 0.18 mg) Test product (Lofexidine tablet 0.18 mg) Batch No.: LGF/R/0.18/014 Batch No.: LGF/R/0.18/036 40°C/75% RH 40°C/75% 40°C/75% RH 40°C/75% Initial Initial 1 Month RH 3 Month 1 Month RH 3 Month Tablets i No sticking No Tablets sticking sticking was No No sticking was was sticking was observed observed also sticking observed. Also observed. was also increase in increase in was impurities are Also observed. impurity levels was observed. impurity levels was observed. observed. well controlled. impurities are well controlled. The above table shows that tablets of batch no. LGF/R/0.18/014 coated with HPMC and even in the presence of desiccant, showed sticking issues at an accelerated condition of 40°C/75% RH. However, tablets of batch no. LGF/R/0.18/036 coated with polyvinyl alcohol (PVA) didn't show any sticking issues at an accelerated condition of 40°C/75% RH. In conclusion, tablets of batch number LGF/R/0.18/036 show excellent content uniformity and remain stable over months of 40°C/75%RH without any sticking. After a satisfactory result of batch no. LGF/R/0.18/036 for the content uniformity property, the said batch was charged for stability to generate further data. Observed values during stability studies were recorded as mentioned in Table no 4-Table No. 4: Comparative physicochemical studies of Test product (Lofexidine Tablet 0.18 mg) at initial and 3 months accelerated condition. Reference Reference Sr. No Test Specif icatio n Product (Lucemyra Tablet 0.18 Product (Lucemyra Tablet 0.18 Test Product (Lofexidine Tablet 0.18 mg) mg) mg) Batch No 3405695 4099314-R LGF/R/0.18/036 Cone lition Initial Initial Initial 40°C/75% RH IMonth 40°C/75% RH 3Month 1 Dissolution in pH 7.2 Phos phate Buffer: Q= 80 % of Lofex 10 Min idine dissol ved at 30 min 86 99 94 97 92 15 Min 91 99 99 96 99 30 Min 91 98 99 97 98 45 Min 91 101 99 97 98 60 Min 91 101 99 97 98 2 Related Substance / Amid 0 amine impur ity NMT 1.0 % 0.62 0.23 0.16 0.53 0.89 Amid e impur ity NMT 1.0% ND ND 0.04 ND ND Nitrile impur ity NMT 1.0 % ND ND ND ND ND Acid impur ity NMT 1.0% ND ND ND 0.07 0.16 Ethyl ester impur ity NMT 1.0 % ND ND ND ND ND Highe St Indivi dual unspe cified impur ity NMT 0.5 % 0.16 0.07 ND ND 0.21 Total impur ity NMT 3.0% 0.83 0.30 0.20 0.60 1.26 NLT 95.0% w/w 3 Assay and NMT 105% w/w 97.6 96.7 101.1 99.2 97.7 Remark: • Up to 3 months of accelerated conditions (40 °C and 75% RH), the physicochemical results were satisfactory. • No sticking was observed in tablets coated with Opadry AMB after 3 months of accelerated testing at 40 °C and 75% RH. Experiment no 3: Formulation with Disintegrant: In the second marketed samples of Lucymera (4099314-R), dissolution was found to be faster as compared to the first marketed samples (3405695). Hence, sodium starch glycolate is added as a disintegrant in the composition of the present invention to achieve a better disintegration time and dissolution. Selection of Disintegrant: Croscarmellose Sodium and Sodium Starch Glycolate are widely used as disintegrants in the pharmaceutical industry. Hence, these two disintegrants were evaluated by performing an API excipient compatibility study. Below are the details of the compatibility study (table no.5) Table No.5 Batch No. Specification LGF/R/0.18/021 (Drug Excipients compatibility study) API + Sodium Starch Glycolate API + Croscarmellose Sodium Condition Initial 1M 40°C /75% RH) Initial 1M 40°C /75% RH) Amido amine impurity NMT 1.0% 0.03 0.31 0.04 1.37 Amide impurity NMT 1.0% ND ND ND ND Acid impurity NMT 1.0% ND ND ND ND Nitrile impurity NMT 1.0% ND ND ND ND Ethyl ester impurity NMT 1.0% ND ND ND ND Single Maximum Unknown Impurity NMT 0.5% ND ND ND ND Total Impurities NMT 2.5% 0.03 0.31 0.04 1.37 Sr. No. Ingredients Lofexidine Tablet 0.18 mg Batch No. LGF/R/0.18/036 1. Lofexidine Hydrochloride 0.20 2. Lactose 87.00 3. Citric acid 12.30 4. Povidone 1.10 5. Microcrystalline cellulose 5.70 6. Sodium Starch Glycolate 5.00 7. Calcium stearate 2.00 8. Sodium lauryl sulphate 0.70 9. Opadry AMB II (PVA base material) 2.00 Manufacturing Process: 1) Citric acid, lactose, microcrystalline cellulose and povidone were mixed h suitable mixer. 2) Povidone, SLS and Lofexidine mixed together to form granulating liquid. 3) Granulating liquid of step 2 was added to dry mixed powder of step 1 usinj modified vessel at controlled rate of addition. 4) Drying of wet mass of step 3 was done using fluid bed processor and milling of dried granules was carried out using multimill with different screen sizes 5) Sodium starch glycolate and Calcium stearate was sifted through suitable sieves and was added to milled granules of step 4 and then compressed tc form tablet. 6) Resultant tablet was coated with Opadry AMB II. 7) Then resultant tablet was packed in suitable packing material. The details about dissolution of batches are summarized in following tables. Table No. 6: Dissolution performed in cone glass jar at 50 rpm Parameter Condition Medium 0.025 M Potassium phosphate buffer, pH 7.2 Volume 500 mL Temperature 37°C±0.5°C Speed 50 rpm Apparatus USP Apparatus 2 (paddles) Time points 5, 10, 15, 20, 30, 45, 60 min and recovery Type of vessel Cone glass vessel Table No. 7: Dissolution data of example 1 in cone glass vessel at 50 rpm Lofexidine Tablets 0.18 mg Batch No.: LGF/R/0.18/036 Time Min Max Avg. % RSD 5 50 63 59 8.1 10 90 97 93 3.2 15 91 97 94 2.1 20 92 97 95 2.2 30 90 97 94 2.8 45 90 97 94 3.2 60 91 97 94 2.5 Rec. 92 96 94 1.7 Table No. 8: Dissolution data of cone glass vessel at SO rpm (marketed sample of lucymera 4099314-R) Lucemyra (Lofexidine Tablets 0.18 mg) Lot No.: 4099314-R Time Min Max Avg. % RSD 5 50 82 64 14.8 10 88 102 99 4.8 15 88 104 99 5.1 20 88 103 99 4.8 30 87 103 98 4.9 45 86 101 97 5.2 60 86 101 97 5.0 Rec. 86 101 98 4.7 Table No. 09: Comparative Content uniformity of Reference product (Lucemyra tablet 0.18 mg) and Test product (Lofexidine Tablet 0.18 me) Sr. No. Test Specification Reference Product (Lucemyra Tablet 0.18 mg) Test Product (Lofexidine Tablet 0.18 mg) Batch No. 4099314-R LGF/R/0.18/036 1. Disintegration Time 4'37"-5' 12" 5' 15" -5' 50" 2. Related Substance Amido amine impurity NMT1.0% 0.23 0.04 Amide impurity NMT1.0% ND ND Nitrile impurity NMT 1.0 % ND ND Acid impurity NMT 1.0 % ND ND Ethyl ester impurity NMT 1.0 % ND ND Highest Individual unspecified impurity NMT 0.5 % 0.07 ND Total impurity NMT 2.5.0% 0.30 0.04 3. Assay NLT 95.0% w/w and NMT 105% w/w 96.7 97.4 4. Content Uniformity 1 For 10 dosage units: Acceptance value