Drug preservative

Control of pH is of critical importance in many industrial operations such as water purification, food and drug preservation, and agriculture. 

TE Haag, DF Loncrini. Esters of para-hydroxybenzoic acid. In JJ Kabara, ed. Cosmetic and Drug Preservation. New York Marcel Dekker, 1984, pp 63-77. 

It is possible to study cilia beat frequency and drug interaction with mucus independently using models such as tissue explants or cultures of ciliated cells or purified mucus preparations. However, these are not able to provide information about mucociliary transport rates. For such studies, a model incorporating the integrated cilia and mucus components is required such as the frog palate. Drugs, preservatives and absorption enhancers, and bioadhesive formulations have been extensively studied in this model [9]. 

Therefore, corneal absorption depends on the integral tear film concentration (also known as the area under the curve) during the first 10 to 20 minutes after instillation of drug. Absorption is subject to modification by many factors, including other drugs, preservatives, infection, inflammation, or neuronal control, which can greatly affect drug bioavailability at the desired site of action. 

The combination of active drug, preservative, and vehicle usually results in a hypotonic formulation (< 290 mOsm). Simple or complex salts, buffering agents, or certain sugars are often added to adjust osmolarity of the solution to the desired value. An osmolarity of 290 mOsm is equivalent to 0.9% saline, and this is the value sought for most ophthalmic and intravenous medications.The ocular tear film has a wide tolerance for variation in osmotic pressure. However, increasing tonicity above that of the tears causes immediate dilution by osmotic water movement from the eyelids and eye. Hypotonic solutions are sometimes used to treat dry eye conditions and to reduce tear osmolarity from abnormally high values. 

Drug + preservative Pilocarpine 2 Severe membrane disruption death and desquamation of... 

Emulsions are formulated for virtually all the major routes of administration, and there are a number of dermatological, oral and, parenteral preparations available commercially. The internal phase may contain water-soluble drugs, preservatives, and flavoring agents whilst the oil phase may itself be therapeutically active or may act as a carrier for an oil-soluble drug. Such preparations provide an effective approach to... 

Kabara, J.J., Cosmetic and Drug Preservation, Principles and Practice, Marcel Dekker, New York, 1984. 

Ans. Drugs, preservatives, and food additives are absorbed along with nutrients and carried to the liver. There the relatively insoluble compounds are detoxified by cytoplasmic oxidases. The reaction produces hydroxylated derivatives which are further combined by esterification to water-soluble compounds and along with originally water-soluble foreign compounds are eliminated in the urine. 

Kabara, J.J. "Ctosmetic Drug Preservation", Marcel Dekker Mew York, 1984, p. 275-304. 

Kabara JJ (1984) Cosmetic and drug preservation. Dekker, New York... 

Cosmetic and Drug Preservation Principles and Practice, edited by Jon J. Kabara... 

Like thickeners, other additives used in pharmaceutical suspensions can affect the potential of the drug. Preservative substances are often used to prevent or at least minimize possible sources of deterioration in pharmaceutical preparations. Preservatives include antimicrobial agents to eliminate or inhibit the growth... 

Hart, J. R., 1984. Chelating agents as preservative potentiators. In J. J. Kabara (ed.). Cosmetic and Drug Preservation. Principles and Practice. New York - Basel, Marcel Dekker, pp. 323-337. 

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