A multicentric, open label, balanced, randomized, two-stage, two-treatment, two-period, two-sequence, crossover, multiple oral dose, comparative bioavailability study of cyclophosphamide powder for oral solution (Test drug from Intas pharmaceutical Ltd., India) with Cyclophosphamide Tablets 50 mg (Reference drug from Baxter) in adult patients with breast cancer.

INTERVENTION: Product Name: Cyclophosphamide powder for oral solution 600 mg / 20 mL Pharmaceutical Form: Powder for oral solution INN or Proposed INN: CYCLOPHOSPHAMIDE CAS Number: 50‐18‐0 Concentration unit: mg/ml milligram(s)/millilitre Concentration type: equal Concentration number: 30‐ Trade Name: Cyclophosphamide Tablets 50 mg Product Name: Cyclophosphamide Tablets 50 mg Pharmaceutical Form: Tablet INN or Proposed INN: CYCLOPHOSPHAMIDE CAS Number: 50‐18‐0 Concentration unit: mg milligram(s) Concentration type: equal Concentration number: 50‐ CONDITION: Adult female patients with breast cancer. ; MedDRA version: 20.0 Level: PT Classification code 10006187 Term: Breast cancer System Organ Class: 10029104 ‐ Neoplasms benign, malignant and unspecified (incl cysts and polyps) Therapeutic area: Diseases [C] ‐ Cancer [C04] PRIMARY OUTCOME: Main Objective: To characterize the pharmacokinetic profile and to compare bioavailability of cyclophosphamide powder relative to cyclophosphamide tablet. Primary end point(s): To characterize the pharmacokinetic profile and to compare bioavailability of cyclophosphamide powder relative to cyclophosphamide tablet. Secondary Objective: ‐ To evaluate taste/palatability of cyclophosphamide powder; ‐ To compare the safety of cyclophosphamide powder relative to cyclophosphamide tablet. Timepoint(s) of evaluation of this end point: Following pharmacokinetic parameters will be evaluated:; ‐ Primary Pharmacokinetic Parameters: Cmax,ss and AUC0‐t,ss; ‐ Secondary Pharmacokinetic Parameters: Tmax,ss, Cav,ss, Ct,ss, %Fluctuation and Cpd SECONDARY OUTCOME: Secondary end point(s): ‐ To evaluate taste/palatability of cyclophosphamide powder; ‐ To compare the safety of cyclophosphamide powder relative to cyclophosphamide tablet. Timepoint(s) of evaluation of this end point: ‐ Test product palatability will be evaluated using palatability evaluation scale in terms of taste, flavor and mouth feel assessment.; ‐ Frequency and/or incidence of significant clinical signs and symptoms, and laboratory abnormalities during treatment INCLUSION CRITERIA: 1. Participant must sign an ICF indicating that she understands the purpose of, and procedures required for the study as described in this protocol and is willing to participate in the study. 2. Participant must be female of weight =40 kg, aged between 18 to 55 years of age inclusive, at the time of signing the informed consent. 3. Participants with documented medical history of histologically or cytologically confirmed breast cancer. 4. Participant must have of HER2 negative, ER/PR positive or negative breast cancer [as defined by American Society for Clinical Oncology (ASCO)‐ College of American Pathologists (CAP) guidelines] confirmed by local laboratory performed on primary tumor and/or metastatic lesion. 5. Patients who are a. Neoadjuvant, adjuvant, recurrent, or metastatic setting AND b. To be initiated on cyclophosphamide 100 mg/m2 (rounded within 5% of the prescribed dose but always in multiples of 50 mg per day) daily for at least 1