A review on role of cleaning validation protocol in Pharmaceutical manufacturing unit

A review on role of cleaning validation protocol inPharmaceutical manufacturing unitK. Harshavardhan*1, V.S.Thiruvengada Rajan 1, N. Amruth Kumar 1, S.Angala Parameswari 1,C.Madhusudhana Chetty 21Department of Pharmaceutical Analysis and Quality Assurance, 2Department of Bio-Technology,Annamacharya College of Pharmacy, Rajampet-516126, Andhra Pradesh, IndiaABSTRACTCleaning validation is must in order to identify and correction of potential problems previously unsuspected which shows effect on safety, efficacy and quality of subsequent batches of drug product with in the equipment. Manu-factures and authorities set high standards for the effective and reliable cleaning of production equipment in or-der to prevent cross contamination. Regulations, tight deadlines and increasing awareness of cost necessitate effi-cient and residue free cleaning processes. Residue free cleaning is a key factor in the life cycle of any chemical pharmaceutical product from research and development in the laboratory during scale up in the pilot plant and finally at the production site. An effective cleaning process takes all the individual factors in to account and is based on precise knowledge of the product mix and cleaning chemistry which results in greater efficiency and lower costs. The benefits due to cleaning validation are compliance with federal regulations, identification and correction of potential problems, previously unsuspected which could compromise the safety and efficacy of drug products.Keywords: Analytical testing methods; cleaning validation protocol; cleaning validation; validation. INTRODUCTIONCleaning validation provides documented evidence that the cleaning methods employed with in a facility are effective and consistent in cleaning pharmaceutical production equipment. Validation of equipment clean-ing procedures is mainly used in pharmaceutical indus-tries to prevent cross contamination and adulteration of drug products. The important task of performing a cleaning validation is to identify and correction of po-tential problems previously unsuspected which shows effect on safety, efficacy, or quality of subsequent batches of drug product produced within the equip-ment. Cleaning validation is important like that of pro-duction process and the process validation. It is there-fore deserves the same careful attention. The main rationale for requiring clean equipment is to prevent contamination or adulterations of drug products (Gala-towitsch S 2000). ObjectiveCleaning validation should be followed for prevention of interactions between active pharmaceutical ingre-dients. The cleaning of difficult to reach surface is oneof the most important consideration in equipment cleaning validation. It is necessary to validate cleaning procedure for the following reasons (Cleaning Valida-tion, 1999)1. Customer requirement-it ensures the safety and the purity of the product.2. Regulatory requirement in active pharmaceutical ingredient product manufacture.3. Assurance from an internal control and compliance point of view the quality of process.When the cleaning process is used only between batches of the same product the firm need to meet criteria of visible clean for the equipment. Residue free cleaning is a key factor in the life cycle of any chemical pharmaceutical product from research and develop-ment in the laboratory during scale up in the pilot plant and finally at the production site. An effective cleaning process takes all the individual factors in to account and is based on a precise knowledge of the product mix and cleaning chemistry (Mendenhall DW 1989). Various types of contaminants Contamination with active ingredientsCross contamination with Active ingredients may cause potential clinically significant synergistic interactions between pharmacologically active chemicals and it causes an unintended pharmacological activity so con-tamination of one batch product with residual active* Corresponding AuthorEmail: harshan17@ Contact: +91-9966981423 Received on: 04.07.2011 Revised on: 25.08.2011 Accepted on: 04.09.2011ISSN: 2231-2935 Review Articleingredient from a previous batch should not be tole-rated if the residues are more than the predetermined level.Contamination with unintended materials or com-poundsPrecursors to active pharmaceutical ingredients. Sol-vents and other materials employed during the manu-facturing process. Cleaning agent themselves and lu-bricants.MICROBIAL CONTAMINATIONThere is chance of microbial growth if the processing equipment is not properly maintained, cleaned and stored.It includes preventive measures rather than removal of contamination (Parentaral drug association, 1998; Cleaning validation, 1999).FDA RequirementsFDA expects firms to have written standard operating procedures (SOP) detailing the cleaning process used for various pieces of equipment. If firms have a specific cleaning process for cleaning between different batches of the same product and use a different process for cleaning between product changes, FDA expects the written procedures to address these dif-ferent scenarios. If firms have one process for remov-ing water-soluble residues and another process for non water soluble residues the written procedure should address both scenarios and make it clear when a given procedure is followed. It is required by the FDA, in the general validation procedure, that the personnel re-sponsible for performing and approving the study should comply with the acceptance criteria and the revalidation data. FDA expects firms to prepare specific written validation protocols in advance for the studies to be performed on each manufacturing system or piece of equipment which should address such issues as sampling procedures, and analytical methods to be used including the sensitivity of those methods. It is expected that firms conduct the validation studies in accordance with the protocols and document the re-sult of studies. Final validation report is to be approved by the regulatory board which states whether or not the cleaning process is valid (FDA guidelines 1993). Cleaning Validation PolicyThe main focus of this document will be to describe equipment and ancillary equipment/ process Cleaning Validation in an Active Pharmaceutical Ingredient manufacturing plant. However, it is appropriate to start by giving a brief introduction as to how the con-cept of Cleaning Validation should be approached in a facility. It is advisable for Active Pharmaceutical Ingre-dient manufacturing facilities to hold an Official Clean-ing Validation Policy. Specific department responsibili-ties should be outlined in this and it should be ap-proved by senior management. This policy should serve to provide a general guideline and direction for com-pany personnel, regulatory authorities and customers as to how the company deals with areas associated with Cleaning Validation. The policy should incorporate the following types of statements∙Definition of terms employed during validation i.e. rinse vs flush vs wash etc.∙A statement specifying what company policy is on validation of cleaning procedures related to equip-ment (including ancillary) and processes.∙Company policy re dedication of equipment in cer-tain cases (if products are deemed too dangerous and / or highly active to manufacture on multi-product equipment).∙Analytical validation policy.∙The policy should also state the rational for the me-thods by which acceptance criteria is determined.∙Revalidation policy (Health Sciences Authority,dec 2008).Acceptance criteria based on therapeutic daily doseThe principle for the requirement is that the standard Therapeutic Daily Dose (TDD)of the following sub-stance (contaminated. substance, in this case called "next") maybe contaminated by no more than a certain proportion (usually 1/1000 part) of the TDD of the sub-stance investigated in the cleaning validation (conta-minating substance, in this case called "previous"). This method only applies when the therapeutic daily dose is known. It is generally used for final product changeov-er API Process A to API Process B.ProcedureEstablish the limit for Maximum Allowable Carryover (MACO) according to the following equation.TDD previous x MBSMACO = ------------------------------SF x TDD nextMACO = Maximum Allowable Carryover: acceptable transferred amount from the investigated product ("previous")TDD previous = Standard therapeutic dose of the investi-gated product (in the same Dosage form as TDD next)TDD next = Standard therapeutic dose of the daily dose for the next productMBS = Minimum batch size for the next product(s) (where MACO can end up)SF = Safety factor (normally 1000 is used in calculations based on TDD)Based In Toxicological DataIn cases in which a therapeutic dose is not known (e.g. for intermediates and detergents), toxicity data may be used for calculating MACO.152 ©JK Welfare & Pharmascope Foundation | International Journal of Review in Life SciencesProcedureCalculate the so called NOEL number (No Observable Effect Level) according to the following equation and use the result for the establishment of MACO.LD50 (g/kg) x 70 (kg a person)NOEL = --------------------------------------2000From the NOEL number a MACO can then be calculated according to:NOEL x MBSMACO = -------------------SF x TDD nextMACO = Maximum Allowable Carryover: acceptable transferred amount from the investigated product ("previous")NOEL = No Observed Effect LevelLD50 = Lethal Dose 50 in g/kg animal.The identification of the animal (mouse, rat etc.) and the way of entry (IV, oral etc.) is important.70 kg = 70 kg is the weight of an average adult2000 = 2000 is an empirical constantTDD next = Largest normal daily dose for the next prod-uctMBS = Minimum batch size for the next product(s) (where MACO can end up)SF = Safety factorThe safety factor (SF) varies depending on the route of administration. Generally a factor of 200 is employed when manufacturing APIs to be administered in oral dosage forms. SF can vary depending on sub-stance/dosage form according to (suppose tox values from oral administration) as for example.Safety factorsTopicals 10- 100Oral products 100 - 1000Parentrals 1000 -10 000To calculate MACO values from tox data is frequently done when therapeutic dosage data is not available or not relevant. It is generally employed if the previous product is an intermediate and the following product an API.Establishment of limitsNMT 0.1% of the normal therapeutic dose of any prod-uct to appear in the maximum daily dose of the follow-ing product. NMT 10ppm of any product to appear in another product. No quantity of residue to be visisble on the equipment after cleaning procedures are per-formed(Fourman GL 1993; Vitale KM 1995; Brewer R 1996). CLEANING PROCEDURESStandard cleaning procedures for each piece of equip-ment and process should be prepared. It is vital that the equipment design is evaluated in detail in conjunc-tion with the product residues which are to be re-moved, the available cleaning agents and cleaning techniques, when determining the optimum cleaning procedure for the equipment. Cleaning procedures should be sufficiently detailed to remove the possibility of any inconsistencies during the cleaning process. Fol-lowing parameters are to be considered during clean-ing procedures (Quality assurance of pharmaceuticals: a compendium of guidelines 2006).Equipment parameters to be evaluated∙Identification of the equipment to be cleaned.∙Difficult to clean areas∙Property of materials∙Ease of disassembly∙MobilityResidues to be cleaned∙Cleaning limits∙Solubility of residues∙Length of campaignsCleaning agent parameters to be evaluated∙Preferable materials that are normally used in the process.∙Detergent available∙Solubility properties∙Environmental considerations∙Health and safety considerationsCleaning techniques to be evaluated∙Manual cleaning∙Clean in place∙Clean out of place∙Semi automatic procedures∙Automatic procedure∙Time consideration∙Number of cleaning cycles.Levels of cleaningThe manufacturing process of an Active Pharmaceuti-cal Ingredient (API) typically consists of various chemi-cal reaction and purification steps followed by physical changes. In general early steps undergo further processing and purification and so potential carryover of the previous product would be removed. Theamount or as we will call it here, level of cleaning re-quired in order to ensure that the API is free from un-acceptable levels of contamination by previous sub-stances varies depending on the step being cleaned and the next substance being manufactured in the same piece of equipment. API‘s and related interm e-diates are often produced in multi-purpose equipment with frequent product changes which results in a high amount of cleaning. During the course of this chapter the reader will be introduced to the concept of using different levels of cleaning, thereby giving the oppor-tunity to minimize the amount of cleaning and cleaning validation required without affecting the safety of the API. The CEFIC, APIC Guide to Cleaning Validation re-commends three levels of cleaning that may be imple-mented. This approach is outlined in the table 1 below, however should be mentioned that additional levels might be necessary depending on nature of the process and requirements of individual companies (Cleaning validation 2000).Table 1: Levels of CleaningSampling TechniquesFor all the methods the sampling points must be fixed in a manner that the true contamination of the equip-ment will be reflected. A combination of rinse sampling and swabbing is the effective method (James A 1992; Parentaral drug association 1998; Pei yang 2005; Hyde JM 1994; James A 1992; Philips GF 1989).Direct Surface SamplingIt will determine the material used for sampling and its impact on the test data since the material used may interfere with the test. For example adhesive materials used in swabs found to interact with the samples dur-ing analysis. AdvantagesAreas which are hardest to clean and reasonably ac-cessible can be evaluated that establishes the level of contamination or residue per given surface area.∙Residues that are not soluble and dried out can be sampled by physical removal.Swab samplingDuring swab sampling usually a small area of the cleaned equipment is swabbed with a pre-defined ma-terial and method (swab material, solvent and tech-nique). Subsequently the swab is extracted and the extract examined by a suitable analytical method. Then the quantified residue of the samples is extrapolated to the whole equipment It includes both physical and chemical forces.It is important:∙That the validation of the swab sampling is per-formed on the same surface (material, polish grade, area in dm2) and with the same materials as the rou-tine sampling of the equipment.∙To choose the swabb ing material such that it’s e x-tractable materials do not interfere with the ex-pected residue.∙To choose the sampling points such that they represent the worst case spots of the equipment AdvantagesIt is possible to sample insoluble residue as physical forces or action is associated with it. DisadvantagesBy this method it is not possible to swab difficult to reach area (e.g. sealing, slots, and condensers, piping). Rinse samplingIn this method the equipment is rinsed with the sol-vent after cleaned. If properly designed this method will probably give the best picture of the amount of the residue in the equipment (Leblane DA 1998). AdvantagesThis method covers the entire surface area of equip-ment even the difficult to reach area and which cannot be disassembled.DisadvantagesThe residue or contaminant may not be soluble or may be physically occluded in the equipment. An analogy that can be used is the dirty pot. In the evaluation of cleaning of a dirty pot, particularly with dried out resi-due, one does not look at the rinse water to see that it is clean one looks at the pot.154 ©JK Welfare & Pharmascope Foundation | International Journal of Review in Life SciencesStampsThis is not routinely used method. Stamps (coins) are placed on the appropriate sampling points in the equipment during the manufacture of product and cleaning. Then these coins are evaluated for contami-nation. From data obtained overall contamination of the equipment is calculated. For quantization the coins may be first swabbed and the samples further ana-lyzed.Routine production in process controlMonitoring indirect testing such as conductivity testing may be performed for routine monitoring once a clean-ing process has been validated. These are true in case of bulk drug substance manufacture where reactors, centrifuges, piping between large equipment can be sampled by rinse solution samples.TESTING METHODSThe analytical methods should be validated. The ana-lytical methods used must be specific towards the resi-duals or contaminants (e.g. product residue, detergent, residue and /or endotoxin). The analytical methods used should have predetermined specificity and sensi-tivity. If levels of contamination or residue are not de-tected, it does not mean that there is no residual con-taminant present after cleaning, it means that the le-vels of contaminant greater than the sensitivity or de-tection limit of the analytical method are not present in the sample. For detection of protein residue the product specific assay(s) can be used in addition to total organic carbon. A negative test may also be the result of poor sampling technique. The firm should challenge the analytical method in combination with the sampling method(s) used to show that contami-nants can be recovered from the equipment surface. There are many analytical techniques available but selection of appropriate tool depends on the parame-ters to be measured. Analytical methods are catego-rized in to specific and non specific methods(Kirsch RB 1998; Cleaning Validation 2000; Kaiser HJ 1999; Gavlick WK 1995; Jenkins KM 1994; Philips GF 1989; LeBlanc DA 1998; Fourman GL 1993; Swartz ME 1998). Specific MethodsIn this method a unique compound can be detected from potential contaminants. E.g. HPLCNon Specific MethodsIn this method any compound can be detected which produces certain response. E.g. Total Organic Carbon, pH and conductivity.HPLCEvery pharmaceutical company has an HPLC instru-ment, utilizing a variety of detectors. These include UV, fluorescence, electrochemical, refractive index, con-ductivity, Evaporate light scattering detector (ELSD) and many others. The vast majority of techniques de-scribed in the literature are for the determination of surfactants in concentrated products. Therefore, the limits of quantitation and the limit of detection are rather high. Analysis of anionic and cationic surfactants is done by HPLC and Capillary electrophoresis whereas amphoteric surfactants are analysed by HPLC, CD and ELSD (Lin W 2000; Heinig K 1997a, 1997b; Schmitt TM 1998; McPherson BP 1994).Capillary electrophoresisCapillary electrophoresis is used to separate, detect and determine sodium lauryl sulphate in cationic, anionic and non ionic surfactants (Kelly MA 1997) (Shamsi SA 1995) micellar electro kinetic capillary chromatography is used for the separation of non ionic alkyl phenol poly oxy ethylene type surfactants (Heinig K 1998; Heinig K 1999)LC-MS-MSCurrently liquid chromatography-ultraviolet spectro-metry is widely used because of its familiarity, robust-ness, ease of use and regulatory acceptability. This method will afford faster development and analysis time, potentially making the predominant tool of choice. This method is widely used for the detection of low dose compounds because of its selectivity and sen-sitivity (Kelvin J 2006)Total Organic CarbonTOC is determined by the oxidation of organic com-pound in to carbon dioxide. The oxidation can occur through a number of mechanisms depending on the instrument being used. TOC is used for the analysis of detergents, endotoxins, biological media and poly ethylene glycol (Jenkins KM 1996; Westman L 2000; Guazzaroni M 1998; Biwald CE 1997).Ion ChromatographyIon chromatography can be used for the analysis of inorganic, organic and surfactants present in the clean-ers. Most of the cleaners contain sodium and or potas-sium. The ion chromatography detection technique of suppressed conductivity is more sensitive to potassium ions than to sodium ions. Very low levels of cleaning agents can be detected by using this technique. Other techniques like TLC, AAS and Bioluminescence are widely used for the qualitative determination of surfac-tants as well as Inorganic contaminants and biological (Hoeft CE 1994; Pan N 1995; Takeda T 1992; Murawski D 1991; Nair LM 1998; Weston A 1998).Thin Layer ChromatographyTLC is useful in the determination in qualitative deter-mination of surfactants (Bosdorf V 1996; Read H 1985; Henrich LH 1992).Atomic Absorption SpectroscopyIt is widely in determination of inorganic surfactants (Raghavan R 2000)BioluminanceIt is widely used in the determination of biological (Da-vidson CA 1999).Optically Simulated Electronic EmissionIn some cases the limits of residue are very less that they cannot be detected by conventional methods. OSEE is very sensitive method that can be used for both qualitative and quantitative manner in this re-gard. Apart from the above mentioned techniques the biopharmaceutical industry utilizes a wide variety of techniques .these include enzyme linked immune sor-bent assay and limulus amaebocyte lysate technique (Inampudi P 1996; Rowell FJ 1998).Cleaning Validation ProtocolCleaning validation should be described in cleaning validation protocols, which should be formally ap-proved, e.g. by the quality control or quality assurance unit (Quality assurance of pharmaceuticals 2006).In preparing the cleaning validation protocol, the fol-lowing should be considered:∙disassembly of system;∙pre cleaning;∙cleaning agent, concentration, solution volume, wa-ter quality;∙time and temperature;∙flow rate, pressure and rinsing;∙complexity and design of the equipment;∙training of operators; and∙size of the systemCleaning Validation ReportA validation report is necessary to present the results and conclusions and secure approval of the study. The report should include the following information: Refer-ences to all the procedures followed to clean the sam-ples and tests. Any recommendations based on the results or relevant information obtained during the study including revalidation practices if applicable. Re-view of any deviations from the protocol. When it is unlikely that further batches of the product will be manufactured for a period of time, it is advisable to generate reports on a batch by batch basis until such time. The report should conclude an appropriate level of verification subsequent to validation (Parentaral drug association 1998; Lakshman Prabu S 2010). CONCLUSIONCleaning validation is required in the pharmaceutical field to avoid potentially clinically significant synergistic interactions between pharmaceutical components. A cleaning validation programme should contain the as-sessment of equipment and products, assessment of the impact of a process on routine process, determina-tion of an appropriate cleaning agent and method, de-termination of acceptance criteria for the residues, determination of a degree of evaluation required to validate the procedure, decisive on the residues to be tested based on the respective parameters. Cleaning validation there by assures the safety and purity of the finished products as well as avoiding cross contamina-tion.REFERENCESBiwald CE, Gavlick WK. Use of Total Organic Carbon Analysis and Fourier-Transform Infrared Spectros-copy to Determine Residues of Cleaning Agents on Surfaces. J AOAC Inte. 1997; 80: 1078-1083.Bosdorf V, Krubmann H. Analysis of Detergents and Cleaning Agents with Thin-Layer Chromatography. Fourth World Surfactants Congressional Association. Barcelona 1996; 4: 92-95.Brewer R. Regulatory aspects of cleaning validation, ISPE seminar, Rockville, Maryland, March 1996.Cleaning Validation in Active Pharmaceutical Ingredient manufacturing plants by Active pharmaceutical in-gredients committee. September 1999.Davidson CA, Griffith CJ, Peters AC, Fielding LM. Evalua-tion of Two Methods for Evaluating Surface Cleanli-ness ATP Bioluminescence and Traditional Hygiene Swabbing. Luminescence. 1999; 14: 33-38.FDA, Guide to inspections of validation of cleaning process division of investigations, Office of regional operations & Office regulatory affairs. 1993.Fourman GL, Mullen MV. Determining cleaning valida-tion acceptance limits for Pharmaceutical manufac-turing operations. Pharm Tech 1993; 54-60.Galatowitsch S. The Importance of Cleaning Validation. Clean rooms 2000; 14(6): 19-22.Gavlick WK, Ohlemeier LA, Kaiser HJ. Analytical Strate-gies for Cleaning Agent Residue Determination. Pharm Tech 1995; 19: 136-144.Guazzaroni M, Yiin B, Yu JL. Application of Total Or-ganic Carbon Analysis for Cleaning Validation in Pharmaceutical Manufacturing. American Biotech Lab 1998; 16(10): 66-67.Guidance on aspects of cleaning validation in active pharmaceutical ingredient plants. Active pharmaceu-tical ingredients committee. Dec-2000.Health Products and Food Branch Inspectorate Good Manufacturing Practices - Cleaning Validation Guide-lines spring 2000.Health Sciences Authority – Health Products Regulation Group Cleaning Validation. Guide-Mqa-008-007, De-cember 2008, 6 – 11.156 ©JK Welfare & Pharmascope Foundation | International Journal of Review in Life SciencesHeinig K, Vogt C, Werner G. Determination of Cationic Surfactants by Capillary Electrophoresis with Indirect Photometric Detection. J Chrom 1997; 781: 17-22. Heinig K, Vogt C, Werner G. Determination of Linear Alkylbenzene-sulfonates in Industrial and Environ-mental Sample by Capillary Electrophoresis. Ana-lyst.1998; 123: 349 - 353.Heinig K, Vogt C, Werner G. Separation of Nonionic Surfactants of the Polyoxyethylene Type by Capillary Electrophoresis. J Anal Chem 1997; 357: 695-700. Heinig K, Vogt C. Determination of Surfactants by Capil-lary Electrophoresis. Electrophoresis 1999; 20: 3311-3328.Henrich LH. Separation and Identification of Surfac-tants in Commercial Cleaners. J Planar Chrom 1992; 5(2): 103-117.Hoeft CE, Zollars RL. Direct Determination of Anionic Surfactants Using Ion Chromatography. J Liq Chrom 1994; 17(12): 2691-2704.Hyde JM. Cleaning validation strategies, ISPE CIP/SIP seminar, Atlanta-Georgia, June 1994.Inampudi P, Lombardo S, Ruezinsky G. An Integrated Approach for Validating Cleaning Procedures in Bio-pharmaceutical Manufacturing Facilities. Annals of the New York Academy of Sciences 1996; 782: 363-374.James A. Points to consider in the validation of equip-ment cleaning procedures. J Parental Sci Tech 1992;46 (5): 163-168.James A. Validation of equipment cleaning procedures, PDA congress, Basel- Switzerland, February 1992. Jenkins KM, Vanderwielen AJ, Armstrong JA. Applica-tion of Total Organic Carbon Analysis to Cleaning Validation. J Sci Tech 1996; 50: 6-15.Jenkins KM, Vanderwielen AJ. Cleaning Validation: An Overall Perspective. Pharm Tech 1994; 18: 60-73. Kaiser HJ, Tirey JF, LeBlanc DA. Measurement of Or-ganic and Inorganic Residues Recovered from Sur-faces. J Valn Tech 1999; 6(1): 424-436.Kelly MA, Altria KD. Clark BJ. Quantitative Analysis of Sodium Dodecyl Sulphate by Capillary Electrophore-sis. J Chrom 1997; 781: 67-71.Kelvin J, Kolodsick, Holly, Philips, Jennifer Feng, Mat-thew Molski, Carol A, Kingsmill. Enhancing drug de-velopment by applying LC-MS-MS for cleaning valida-tion in manufacturing equipment. Pharmaceutical Technology, Feb 2, 2006.Kirsch RB. Validation of Analytical Methods Used in Pharmaceutical Cleaning Assessment and Validation. Pharm Tech 1998; 40-46. LakshmanaPrabu S, Suriyaprakash TNK. Cleaning Vali-dation and its importance in Pharmaceutical Indus-try. Pharma Times 2010; 42(7).LeBlanc DA. Establishing Scientifically Justified Accep-tance Criteria for Cleaning Validation of Finished Drug Products. Pharm Tech 1998; 22(10): 136-148.Leblane DA. Rinse sampling for cleaning validation studies. Pharm Tech 1998; 22(5): 66-74.Lin W, Lin S, Shu S. Comparison of Analyses of Surfac-tants in Cosmetics Using High-Performance Liquid Chromatography and High Performance Capillary Electrophoresis. J surfactants and detergents 2000; 3(1): 67-72.McPherson BP, Rasmussen HT. Chromatography of Cationic Surfactants: HPLC, TLC, and GLC. Cationic Surfactants. Surfactant science. New York: Marcel Dekker. 1994; 289-326.Mendenhall DW. Cleaning validation. Drug Dev Ind Pharm 1989; 15(13): 2105-2114.Murawski D. Ion Chromatography for the Analysis of Household Consumer Products. J Chrom 1991; 546: 351-367.Nair LM, Saari Nordhaus R. Recent Developments in Surfactant Analysis by Ion Chromatography. J Chrom 1998; 804: 233-239.Pan N, Pietrzyck DJ. Separation of Anionic Surfactants on Anion Exchangers. J Chrom 1995; 706: 327-337.Parenteral Drug Association. Points to Consider for Cleaning Validation. Technical Report No. 29; 1998.Pei Yang, Kim Burson, Debrafeder, Fraser Macdonald. Method development of swab sampling Afor clean-ing validation of a residual active pharmaceutical in-gredient. Pharmaceutical Technology, 2005, 84-92. Phillips GF. The need for impurity control. Die Pharm Ind 1989; 51(11): 1282-1286.Quality assurance of pharmaceuticals: a compendium of guidelines and related materials. Good manufac-turing practices and inspection, 2nd edition, vol 2. 2006.Raghavan R, Mulligan JA. Low-Level (PPB) Determina-tion of Cisplatin in Cleaning Validation (Rinse Water) Samples. I. An Atomic Absorption Spectrophotomet-ric Technique. Drug Device Ind Pharm. 2000; 26(4): 423-428.Read H. Surfactant Analysis Using HPTLC and the Latro-scan. Proceedings of the International Symposium on Instrumental High Performance Thin-Layer Chroma-tography. Institute of Chromatography. Federal Re-public of Germany 3rd ed, 1985; 157-171.Richard J, Julia Roberts, Vincent van Nostrand, TaraLuk-ievis. Correlation of visible –residue limits with swab©JK Welfare & Pharmascope Foundation | International Journal of Review in Life Sciences157。