Image downloaded from pixabay.com(copyright free) Antioxidants may be described as compounds which have the capability of functioning chemically as reducing agent.They are used in pharmaceutical formulations containing easily oxidized substances in order to keep the substance in their oxidized form. The Mechanism of antioxidant action may be seen in two ways,both achieving the same net result : The active component is oxidized,the antioxidant reduces it back to its normal oxidation state. The antioxidant is oxidized in the place of active constituent. THE THEORY OF ANTIOXIDANTS  Antioxidant action is same as that involved in any oxidation-reduction or Redox reaction.For example,the usual way of examining a Redox reaction is to separate it into half-cell reaction of the oxidizing and reducing agents.Since in Redox reaction,there is a transfer of electron from one compound to other,the loss of gain of electron is used to balance the oxidation states on both sides of the half - cell react

The chemistry of glass is extremely complicated.The word " glass " is a generic term referring to vitreous material (material which softens gradually over a temperature range rather than melting sharply).Most commercial glasses are vitreous silicates with some type of additives which confers special properties.Boron decreases the coefficient of expansion in PYREX Glass.Potassium gives a brown light-resistant glass.The rare earths selectively absorb light of certain wavelengths. Glass may be considered as SODIUM SILICATE ( Na 4 SiO 4 ). Aqueous solutions may slowly become alkaline upon standing for prolonged times in soft glass containers.It is shown by the reaction given below: 4Na + + SiO 4 -4 + 3H 2 0 ⟶ H 3 SiO 4 - + 4Na +  + 3OH - The compendia usually specify the type of glass container if the drug is base-sensitive.The water for injection must be stored in glass of TYPE Ⅰ or Ⅱ as the above reaction is greatly speeded up during heat sterilization.Both the U.S.P

The pH Of Solutions The concept of pH is very convenient for expressing Hydrogen ion concentration.It was introduced by SORENSEN in 1909.Hydrogen ion concentration [H + ] are typically quite small numbers.Therefore,it can be expressed in terms of pH. pH is defined as the negative logarithm(log) of the base 10 of the H + concentration. Mathematically,it may be expressed as pH = -log[ H + ],where[ H + ] is the concentration of hydrogen ion in moles per litre. To calculate Hydrogen ion concentration we go through following step: Pure water ionises as follows- H 2 O  ⇌ H + +  OH - We can write the equilibrium expression as K = [H + ][OH - ] / [H 2 O] Since,water is so little dissociated,the concentration of on-dissociated molecules[H 2 O], is presumed to be constant.We can write K [H 2 O] = [H][OH - ] Kw = [ H + ][OH - ] where Kw is called product of ionic water and is value is 1 x 10 -14 at 25℃,i.e Kw = [ H + ][OH - ] log Kw = log[ H + ] + log[OH - ] -log Kw = -log[ H + ] - log[OH - ]

This Blog shows discussion of several topics important to the preparation,preservation and storage of pharmaceutical products.The major topics include ACIDS and BASES - frequently employed in the conversion of drugs to chemical forms convenient to their product formulation;BUFFERS - used to maintain the pH of various formulations within Prescribed Limits .

POSOLOGY (Greek ' Posos -HOW MUCH and logos -SCIENCE') is the science of doses .Since the optimum dose of drug to produce the desired therapeutic effect varies from person to person,therefore the doses of drug are actually expressed in the form of range.The prescribed dose is that which exert the Therapeutic effect in the majority of subject.It should be minimum for eliciting the desired therapeutic response and maximum that can be tolerated by an average subject.

Drugs cannot be used for administration in their native forms,and in order to obtain the maximum therapeutic effect, it is formulated or design in to dosage forms such as  Tablets,Capsules,Solutions,Suspension,Ointment etc.

Dosage Forms is a blend of drug component with non - drug component produced in definite physical forms,shape and size intended to be administered by a particular route of administration.These include tablets,capsules,solutions,suspension and creams.

According to route of administration, the other   type of dosage forms are   Rectal,Parenteral, Vaginal,Inhaled,Ophthalmic,Otic and Nasal

According to route of administration, the second type of dosage forms are Topical Dosage Forms.                                              Topical Dosage Forms  Topical Dosage forms are defined as the the medication which are meant to be applied on the surface of the body externally. Topical semi-solid dosage forms are normally presented in the form of creams, gels, ointments, or pastes. They contain one or more active ingredients dissolved or uniformly dispersed in a suitable base and any suitable excipients such as emulsifiers, viscosity-increasing agents, antimicrobial agents, antioxidants, or stabilizing agents. Preparations susceptible to the growth of microorganisms should contain a suitable antimicrobial agent in an appropriate concentration unless the preparations themselves have adequate antimicrobial properties. Assurance must be provided through product development studies that such excipients do not adversely affect either the stability of the final product or t

Dosage Form :- Dosage form is a blend of drug component with a non-drug component produced in a definite physical form,shape,size and intended to be administered by a particular route of administration.These include tablets, capsules, solutions, suspensions, creams etc. The Need for Dosage Forms: 1- Accurate dose. 2- Protection e.g. coated tablets, sealed ampules. 3- Protection from gastric juice. 4- Masking taste and odour. 5- Placement of drugs within body tissues. 6- Sustained release medication. 7- Controlled release medication. 8- Optimal drug action. 9- Insertion of drugs into body cavities (rectal, vaginal). 10- Use of desired vehicle for insoluble drugs.  Classification Of Dosage Form : They are classified according to:- Route of administration-  1)Oral : Oral dosage forms are  dosage forms which are meant to be taken orally.These include  Tablet, Buccal and Sublingual tablet , Effervescent tablet,Chewabl